| draft-ietf-sigtran-sua-04 Description: Request For Comments
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INTERNET-DRAFT J. Loughney
Internet Engineering Task Force Nokia
G. Sidebottom, Guy Mousseau
Issued: 24 November 2000 Nortel Networks
Expires: 24 May 2001 S. Lorusso
Unisphere Solutions
L. Coede, G. Verwimp
Siemens
J. Keller
Tekelec
F. Escobar
Ericsson
W. Sully, S. Furniss
Marconi
SS7 SCCP-User Adaptation Layer (SUA)
<draft-ietf-sigtran-sua-04.txt>
Status of This Memo
This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC 2026.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts.
Internet-Drafts are draft documents valid for a maximum of six
months and may be updated, replaced, or obsoleted by other documents
at any time. It is inappropriate to use Internet-Drafts as
reference material or to cite them other than as 'work in progress.'
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html .
This draft expires on 24 May 2001
Abstract
This Internet Draft defines a protocol for the transport of any SS7
SCCP-User signaling (e.g., TCAP, RANAP, etc.) over IP using the
Stream Control Transport Protocol. The protocol should be modular
and symmetric, to allow it to work in diverse architectures, such as
a Signaling Gateway to IP Signaling Endpoint architecture as well as
a peer-to-peer IP Signaling Endpoint architecture. Protocol
elements are added to allow seamless operation between peers in the
SS7 and IP domains.
Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
Abstract..............................................................1
1. Introduction.......................................................3
1.1 Scope ...........................................................3
1.2 Terminology .....................................................3
1.3 Signaling Transport Architecture ................................5
1.4 Services Provided by the SUA Layer .............................10
1.5 Internal Functions Provided in the SUA Layer ...................11
1.6 Definition of SUA Boundaries ...................................12
2 Conventions........................................................13
3 Protocol Elements..................................................13
3.1 Common Message Header ..........................................14
3.2 SUA Connectionless Messages ....................................17
3.3 Connection Oriented Messages ...................................18
3.4 SS7 Signaling Network Management Messages ......................26
3.5 Application Server Process Maintenance Messages ................31
3.6 ASP Traffic Maintenance Messages ...............................34
3.7 Management Messages ............................................37
3.8 Common Parameters ..............................................38
3.9 SUA-Specific parameters ........................................46
4 Procedures.........................................................59
4.1 Peer Message Procedures ........................................59
4.2 Signaling Gateway Related Procedures ...........................60
4.3 Layer Management Procedures ....................................61
4.4 SCTP Management Procedures .....................................61
5 Examples of SUA Procedures.........................................68
5.1 SG Architecture ................................................68
5.2 IP-IP Architecture .............................................70
6 Message Routing Scenarios..........................................72
6.1 Basic case with single SG acting as end- or relay-point ........72
6.2 Replicated SG acting as end-point ..............................74
6.3 Replicated SG acting as relay-point ............................74
7 Security...........................................................75
7.1 Introduction ...................................................75
7.2 Threats ........................................................75
7.3 Protecting Confidentiality .....................................76
8 IANA Considerations................................................76
8.1 SCTP Payload Protocol ID .......................................76
8.2 Port Number ....................................................76
8.3 IETF Defined Message Classes ...................................77
9 Timer Values.......................................................78
10 Acknowledgements..................................................78
10 Authors' Addresses................................................78
11 References........................................................79
Appendix A: Message mapping between SCCP and SUA.....................80
Appendix B: Message Mapping Examples.................................82
1 SUA->SCCP ........................................................82
2 SCCP->SUA ........................................................82
Copyright Statement..................................................82
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
1. Introduction
1.1 Scope
There is on-going integration of SCN networks and IP networks.
Network service providers are designing all IP architectures which
include support for SS7 and SS7-like signaling protocols. IP
provides an effective way to transport user data and for operators
to expand their networks and build new services. In these networks,
there may be some need for interworking between the SS7 and IP
domains.
This document details the delivery of SCCP-user messages (MAP & CAP
over TCAP, RANAP, etc.) and new third generation network protocol
messages over IP between two signaling endpoints. Consideration is
given for the transport from an SS7 Signaling Gateway (SG) to an IP
signaling node (such as an IP-resident Database) as described in the
Framework Architecture for Signaling Transport [2719]. This protocol
can also support transport of SCCP-user messages between two
endpoints wholly contained within an IP network.
The delivery mechanism SHOULD meet the following criteria:
* Support for transfer of SS7 SCCP-User Part messages (e.g., TCAP,
RANAP, etc.)
* Support for SCCP connectionless service.
* Support for SCCP connection oriented service.
* Support for the seamless operation of SCCP-User protocol peers
* Support for the management of SCTP transport associations between
a SG and one or more IP-based signaling nodes).
* Support for distributed IP-based signaling nodes.
* Support for the asynchronous reporting of status changes to
management
The protocol is modular in design, allowing different
implementations to be made, based upon the environment that needs to
be supported. Depending upon the upper layer protocol supported, the
SUA will need to support SCCP connectionless service, SCCP connect-
orient service or both services.
1.2 Terminology
Signaling Gateway (SG) - Network element that terminates SCN
signaling and transports SCCP-User signaling over IP to an IP
signaling endpoint. A Signaling Gateway could be modeled as one or
more Application Servers, which is located at the border of the SS7
and IP networks.
Application Server (AS) - A logical entity serving a specific
Routing Key. An example of an Application Server is an IP database
handling all request for a unique set of SCCP-users. The AS
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
contains a set of one or more unique Application Server Processes,
of which one or more is normally actively processing traffic.
Application Server Process (ASP) - An Application Server Process
serves as an active or standby process of an Application Server
(e.g., part of a distributed signaling node or database element).
Examples of ASPs are MGCs, IP SCPs, or IP-based HLRs. An ASP
contains an SCTP end-point and may be configured to process traffic
within more than one Application Server.
Association - An association refers to an SCTP association. The
association provides the transport for the delivery of SCCP-User
protocol data units and SUA adaptation layer peer messages.
Routing Key - The Routing Key describes a set of SS7 parameter and
/or parameter-ranges that uniquely defines the range of signaling
traffic configured to be handled by a particular Application Server.
An example would be where a Routing Key consists of a particular PC
and SSN to which all traffic would be directed to a particular
Application Server. Routing Keys are mutually exclusive in the
sense that a received SS7 signaling message cannot be directed to
more than one Routing Key. A Routing Key cannot extend across more
than a single SS7 PC, in order to more easily support SS7 Management
procedures. It is not necessary for the parameter ranges within a
particular Routing Key to be contiguous.
Routing Context - An Application Server Process may be configured to
process traffic within more than one Application Server. In this
case, the Routing Context parameter is exchanged between two ASPs,
identifying the relevant Application Server. From the perspective
of an ASP, the Routing Context uniquely identifies the range of
traffic associated with a particular Application Server, which the
ASP is configured to receive. There is a 1:1 relationship between a
Routing Context value and a Routing Key within an AS. Therefore the
Routing Context can be viewed as an index into an AS Table
containing the AS Routing Keys.
Fail-over - The capability to re-route signaling traffic as required
to an alternate Application Server Process, or group of ASPs, within
an Application Server in the event of failure or unavailability of a
currently used Application Server Process. Fail-back may apply upon
the return to service of a previously unavailable Application Server
Process.
Signaling Point Management Cluster (SPMC) - A complete set of
Application Servers represented to the SS7 network under the same
SS7 Point Code. SPMCs are used to sum the availability / congestion
/ User_Part status of an SS7 destination point code that is
distributed in the IP domain, for the purpose of supporting
management procedures at an SG.
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
Network Appearance - The Network Appearance identifies an SS7
network context for the purposes of logically separating the
signaling traffic between the SG and the Application Server
Processes over a common SCTP Association. An example is where an SG
is logically partitioned to appear as an element in four separate
national SS7 networks. A Network Appearance implicitly defines the
SS7 Point Code(s), Network Indicator and SCCP protocol
type/variant/version used within a specific SS7 network partition.
An physical SS7 route-set or link-set at an SG can appear in only
one network appearance. The Network Appearance is not globally
significant and requires coordination only between the SG and the
ASP.
Network Byte Order - Most significant byte first, a.k.a. Big Endian.
Layer Management - Layer Management is a nodal function in an SG or
ASP that handles the inputs and outputs between the SUA layer and a
local management entity.
Host - The computing platform that the ASP process is running on.
Stream - A stream refers to an SCTP stream; a uni-directional
logical channel established from one SCTP endpoint to another
associated SCTP endpoint, within which all user messages are
delivered in-sequence except for those submitted to the un-ordered
delivery service.
Transport address - an address which serves as a source or
destination for the unreliable packet transport service used by
SCTP. In IP networks, a transport address is defined by the
combination of an IP address and an SCTP port number. Note, only
one SCTP port may be defined for each endpoint, but each SCTP
endpoint may have multiple IP addresses.
1.3 Signaling Transport Architecture
The framework architecture that has been defined for SCN signaling
transport over IP [2719] uses multiple components, including an IP
transport protocol, a signaling common transport protocol and an
adaptation module to support the services expected by a particular
SCN signaling protocol from its underlying protocol layer.
In general terms, the SUA architecture can be modeled as a peer-to-
peer architecture.
1.3.1 Protocol Architecture for TCAP Transport
In this architecture, the SCCP and SUA layers interface in the SG.
There needs to be interworking between the SCCP and SUA layers to
provide for the seamless transfer of the user messages as well as
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
the management messages. The SUA handles the SS7 address to IP
address mapping.
******** SS7 *************** IP ********
* SEP *---------* *--------* *
* or * * SG * * ASP *
* STP * * * * *
******** *************** ********
+------+ +------+
| TCAP | | TCAP |
+------+ +------+------+ +------+
| SCCP | | SCCP | SUA | | SUA |
+------+ +------+------+ +------+
| MTP3 | | MTP3 | | | |
+------| +------+ SCTP | | SCTP |
| MTP2 | | MTP2 | | | |
+------+ +------+------+ +------+
| L1 | | L1 | IP | | IP |
+------+ +------+------+ +------+
| | | |
+---------------+ +------------+
TCAP - Transaction Capability Application Protocol
STP - SS7 Signaling Transfer Point
1.3.2 Protocol Architecture for RANAP Transport
In this architecture, the SS7 application protocol is invoked at the
SG. For messages destined for an ASP, the SUA handles address
translation, for example by way of Global Title Translation or via
mapping table, resolving the destination specified by SS7
Application to a SCTP association / IP address.
******** SS7 *************** IP ********
* SEP *---------* *--------* *
* or * * SG * * ASP *
* STP * * * * *
******** *************** ********
+------+ +-------------+ +------+
| S7AP | | S7AP | | S7AP |
+------+ +------+------+ +------+
| SCCP | | SCCP | SUA | | SUA |
+------+ +------+------+ +------+
| MTP3 | | MTP3 | | | |
+------| +------+ SCTP | | SCTP |
| MTP2 | | MTP2 | | | |
+------+ +------+------+ +------+
| L1 | | L1 | IP | | IP |
+------+ +------+------+ +------+
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
| | | |
+---------------+ +------------+
S7AP - SS7 Application Protocol (e.g. - RANAP/RNSAP)
STP - SS7 Signaling Transfer Point
This architecture may simplify, in some cases, to carrying an SS7
application protocol between two IP based endpoints. In this
scenario, full SG functionality may not be needed. This
architecture is considered in the next section.
1.3.3 All IP Architecture
This architecture can be used to carry a protocol which uses the
transport services of SCCP, but is contained with an IP network.
This allows extra flexibility in developing networks, especially
when interaction between legacy signaling is not needed. The
architecture removes the need for signaling gateway functionality.
******** IP ********
* *--------* *
* AS * * AS *
* * * *
******** ********
+------+ +------+
| AP | | AP |
+------+ +------+
| SUA | | SUA |
+------+ +------+
| SCTP | | SCTP |
+------+ +------+
| IP | | IP |
+------+ +------+
| |
+----------------+
AP - Application Protocol (e.g. - RANAP/RNSAP)
In the case where a collision occurs during initiation, there exist
two possible solutions: 1) if there are sufficient resources, both
initiations could be accepted; 2) both ASPs should back-off and
after some amount of time, later re-establish an initiation.
1.3.4 Generalized Point-to-Point Network Architecture
Figure 1 shows an example network architecture which can support
robust operation and failover support. There needs to be some
management resources at the AS to manage traffic.
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
***********
* AS1 *
* +-----+ * SCTP Associations
* |ASP1 +-------------------+
* +-----+ * | ***********
* * | * AS3 *
* +-----+ * | * +-----+ *
* |ASP2 +-----------------------------------------+ASP1 | *
* +-----+ * | * +-----+ *
* * | * *
* +-----+ * | * +-----+ *
* |ASP3 | * +--------------------------+ASP2 | *
* +-----+ * | | * +-----+ *
*********** | | ***********
| |
*********** | | ***********
* AS2 * | | * AS4 *
* +-----+ * | | * +-----+ *
* |ASP1 +--------------+ +---------------------+ASP1 | *
* +-----+ * * +-----+ *
* * * *
* +-----+ * * +-----+ *
* |ASP2 +-----------------------------------------+ASP1 | *
* +-----+ * * +-----+ *
* * ***********
* +-----+ *
* |ASP3 | *
* +-----+ *
* *
***********
Figure 1: Generalized Architecture
In this example, the Application Servers are shown residing within
one logical box, with ASPs located inside. In fact, an AS could be
distributed among several hosts. In such a scenario, the host
should share state as protection in the case of a failure.
Additionally, in a distributed system, one ASP could be registered
to more than one AS. This draft should not restrict such systems -
though such a case in not specified.
1.3.5 Generalized Signaling Gateway Network Architecture
When interworking between SS7 and IP domains is needed, the SG acts
as the gateway node between the SS7 network and the IP network. The
SG will transport SCCP-user signaling traffic from the SS7 network
to the IP-based signaling nodes (for example IP-resident
Databases). The Signaling Gateway can be considered as a group of
Application Servers with additional functionality to interface
towards an SS7 network.
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
The SUA protocol should be flexible enough to allow different
configurations and transport technology to allow the network
operators to meet their operation, management and performance
requirements.
Figure 2 shows a possible realization of this architecture, with
Signaling Gateway functionality.
Signaling Gateway
****************
* +----------+ * **************
* | AS1 | * * AS3 *
* | ******** | * * ******** *
* | * ASP1 +---------------------------------------------+ ASP1 * *
* | ******** | * * ******** *
* | ******** | * * ******** *
* | * ASP2 +--------------------------+ +----------+ ASP2 * *
* | ******** | * | | * ******** *
* +----------+ * | | * . *
* +----------+ * | | * . *
* | AS2 | * | | * . *
* | ******** | * | | * ******** *
* | * ASP1 +----------------------------------+ * * ASPN * *
* | ******** | * SCTP Associations | * ******** *
* | ******** | * | **************
* | * ASP2 +---------------- |
* | ******** | * | | **************
* +----------+ * | | * AS4 *
**************** | | * ******** *
| +------------------+ ASP1 * *
| * ******** *
| * . *
| * . *
| * *
| * ******** *
+-----------------------------+ ASPn * *
* ******** *
**************
Figure 2: Signaling Gateway Architecture
1.3.6 ASP Fail-over Model and Terminology
The SUA protocol supports ASP fail-over functions in order to
support a high availability of transaction processing capability.
An Application Server can be considered as a list of all ASPs
configured/registered to handle SCCP-user messages within a certain
range of routing information, known as a Routing Key. One or more
ASPs in the list may normally be active to handle traffic, while
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
others may while any others are inactive but available in the event
of failure or unavailability of the active ASP(s).
The fail-over model supports an "n+k" redundancy model, where "n"
ASPs is the minimum number of redundant ASPs required to handle
traffic and "k" ASPs are available to take over for a failed or
unavailable ASP. Note that "1+1" active/standby redundancy is a
subset of this model. A simplex "1+0" model is also supported as a
subset, with no ASP redundancy.
To avoid a single point of failure, it is recommended that a minimum
of two ASPs be resident in the list, resident in separate physical
hosts and therefore available over different SCTP Associations.
1.4 Services Provided by the SUA Layer
1.4.1 Support for the transport of SCCP-User Messages
The SUA needs to support the transfer of SCCP-user messages. The SUA
layer at the SG needs to seamlessly transport the user messages.
1.4.2 SCCP Protocol Class Support
Depending upon the SCCP-users supported, the SUA shall support the 4
possible SCCP protocol classes transparently. The SCCP protocol
classes are defined as follows:
* Protocol class 0 provides unordered transfer of SCCP-user
messages in a connectionless manner.
* Protocol class 1 allows the SCCP-user to select the in-sequence
delivery of SCCP-user messages in a connectionless manner.
* Protocol class 2 allows the bi-directional transfer of SCCP-user
messages by setting up a temporary or permanent signaling
connection.
* Protocol class 3 allows the features of protocol class 2 with
the inclusion of flow control. Detection of message loss or
mis-sequencing is included.
Protocol classes 0 and 1 make up the SCCP connectionless service.
Protocol classes 2 and 3 make up the SCCP connection-oriented
service.
1.4.3 Native Management Functions
The SUA layer may provide management of the underlying SCTP layer to
ensure that transport is available according to the degree specified
by the SCCP-user application.
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The SUA layer provides the capability to indicate errors associated
with the SUA-protocol messages and to provide notification to local
management and the remote peer as is necessary.
1.4.4 Interworking with SCCP Network Management Functions
The SUA layer needs to support the following SCCP network management
primitives (a reference to ITU and ANSI sections where these
primitives and corresponding parameters are described, is also
given):
Generic |Specific |
Name |Name |ANSI/ITU Reference
----------+-----------+---------------------------------------------
N-Coord |Request |ITU-Q.711 Chap 6.3.2.3.1 (Tab 13/Q.711)
|Indication |ANSI-T1.112 Chap 2.3.2.3.1 (Tab 8D/T1.112.1)
|Response |
|Confirm |
----------+-----------+---------------------------------------------
N-State |Request |ITU-Q.711 Chap 6.3.2.3.2 (Tab 14/Q.711)
|Indication |ANSI-T1.112 Chap 2.3.2.3.2 (Tab 8E/T1.112.1)
----------+-----------+---------------------------------------------
N-Pcstate |Indication |ITU-Q.711 Chap 6.3.2.3.3 (Tab 15/Q.711)
| |ANSI-T1.112 Chap 2.3.2.3.4 (Tab 8G/T1.112.1)
1.4.5 Support for the management between the SG and ASP.
The SUA layer should provide interworking with SCCP management
functions at the SG for seamless inter-operation between the SCN
network and the IP network. It should:
* Provide an indication to the SCCP-user at an ASP
that a remote SS7 endpoint/peer is unreachable.
* Provide an indication to the SCCP-user at an ASP
that a remote SS7 endpoint/peer is reachable.
* Provide congestion indication to SCCP-user at an ASP.
* Provide the initiation of an audit of remote SS7
endpoints at the SG.
1.5 Internal Functions Provided in the SUA Layer
1.5.1 Address Translation and Mapping at the SG
SCCP users may present the following options to address their peer
endpoints:
Global Title
PC + SSN
Host Name
IP Address(es)
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
The SG MUST translate the SS7 address presented at the SG (PC + SSN
or GT) to an SCTP-based ASP final destination, and not to another
SS7 MTP destination.
Global Titles are an interesting option for addressing. Currently,
the ITU does not support translation of Global Titles to IP
addresses. However, IP addresses are global in scope. There exist
many proprietary schemes for managing SS7 Address Translation to IP
addresses, and is considered outside of the scope of this document
to specify how this is done.
Some discussion of address translation should be made to insure
interoperability between implementations of the SUA. For further
instruction in the use of Global Titles the rules detailed in Annex
B of ITU Q.713 [ITU SCCP] or [ANSI SCCP] should be consulted.
That being said, currently, there is some work within the IETF
studying translation of E.164 numbers to Host Names [ENUMS], [E.164-
DNS].
In many cases, the network operator may have some control over the
SCCP-user protocols being transported by SUA. If possible, the
Upper Layer can present a Host Name or IP Address, which then can be
directly passed to SCTP.
An example of address translation at the SG would be that the CDPA
is extracted from the SCCP Header, processed by the SUA routing
function which yields a SA. The SA is fed back into extended SUA
routing analysis which yields the ASP to route the message to. This
is why the Source Address and Destination address-routing should be
performed based on the CDPA.
1.5.2 SCTP Stream Mapping
The SUA supports SCTP streams. The SG/AS needs to maintain a list of
SCTP and SUA-users for mapping purposes. SCCP-users requiring
sequenced message transfer need to be sent over a stream supporting
sequenced delivery.
SUA MUST use stream 0 for SUA management messages. It is recommended
that sequenced delivery be in order to preserve the order of
management message delivery.
1.6 Definition of SUA Boundaries
1.6.1 Definition of the upper boundary
The following primitives are supported between the SUA and an SCCP-
user (a reference to ITU and ANSI sections where these primitives
and corresponding parameters are described, is also given):
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Generic |Specific |
Name |Name |ANSI/ITU Reference
------------+----------+-------------------------------------------
N-Connect |Request |ITU-Q.711 Chap 6.1.1.2.2 (Tab 2/Q.711)
|Indication|ANSI-T1.112 Chap 2.1.1.2.2 (Tab 2/T1.112.1)
|Response |
|Confirm |
------------+----------+-------------------------------------------
N-Data |Request |ITU-Q.711 Chap 6.1.1.2.3 (Tab 3/Q.711)
|Indication|ANSI-T1.112 Chap 2.1.1.2.3 (Tab 3/T1.112.1)
------------+----------+-------------------------------------------
N-Expedited |Request |ITU-Q.711 Chap 6.1.1.2.3 (Tab 4/Q.711)
Data |Indication|ANSI-T1.112 Chap 2.1.1.2.3 (Tab 4/T1.112.1)
------------+----------+-------------------------------------------
N-Reset |Request |ITU-Q.711 Chap 6.1.1.2.3 (Tab 5/Q.711)
|Indication|ANSI-T1.112 Chap 2.1.1.2.3 (Tab 5/T1.112.1)
|Response |
|Confirm |
------------+----------+-------------------------------------------
N-Disconnect|Request |ITU-Q.711 Chap 6.1.1.2.4 (Tab 6/Q.711)
|Indication|ANSI-T1.112 Chap 2.1.1.2.4 (Tab 6/T1.112.1)
------------+----------+-------------------------------------------
N-Inform |Request |ITU-Q.711 Chap 6.1.1.3.1 (Tab 7/Q.711)
|Indication|ANSI-T1.112 Chap 2.1.1.2.5 (Tab 6A/T1.112.1)
------------+----------+-------------------------------------------
N-Unit Data |Request |ITU-Q.711 Chap 6.2.2.3.1 (Tab 10/Q.711)
|Indication|ANSI-T1.112 Chap 2.2.2.3.1 (Tab 8A/T1.112.1)
------------+----------+-------------------------------------------
N-Notice |Indication|ITU-Q.711 Chap 6.2.2.3.2 (Tab 11/Q.711)
| |ANSI-T1.112 Chap 2.2.2.3.2 (Tab 8B/T1.112.1)
1.6.2 Definition of the lower boundary
The upper layer primitives provided by the SCTP are provided in
[SCTP].
2 Conventions
The keywords MUST, MUST NOT, REQUIRED, SHALL, SHALL NOT, SHOULD,
SHOULD NOT, RECOMMENDED, NOT RECOMMENDED, MAY, and OPTIONAL, when
they appear in this document, are to be interpreted as described in
[RFC2119].
3 Protocol Elements
The general message format includes a Common Message Header together
with a list of zero or more parameters as defined by the Message
Type.
For forward compatibility, all Message Types may have attached
parameters even if none are specified in this version.
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3.1 Common Message Header
The protocol messages for the SCCP-User Adaptation Protocol requires
a message structure which contains a version, message type, message
length and message contents. This message header is common among
all signaling protocol adaptation layers:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version | Reserved | Message Class | Message Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Message Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| msg data |
Note that the 'data' portion of SUA messages SHALL contain SCCP-User
data, not the encapsulated SCCP message.
Optional parameters can only occur at most once in an SUA message.
3.1.1 SUA Protocol Version
The version field (ver) contains the version of the SUA adaptation
layer. The supported versions are:
01 SUA version 1.0
3.1.2 Message Classes
Message Classes
0 Management (MGMT) Message
1 Reserved
2 SS7 Signaling Network Management (SSNM) Messages
3 ASP State Maintenance (ASPSM) Messages
4 ASP Traffic Maintenance (ASPTM) Messages
5 Reserved
6 Reserved
7 Connectionless Messages
8 Connection-Oriented Messages
9 - 127 Reserved by the IETF
128 - 255 Reserved for IETF-Defined Message Class Extensions
3.1.3 Message Types
SUA Management Messages
0 Error (ERR)
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1 Notify (NTFY)
2 - 127 Reserved by the IETF
128- 255 Reserved for IETF-Defined Message Class Extensions
SS7 Signaling Network Management (SSNM) Messages
0 Reserved
1 Destination Unavailable (DUNA)
2 Destination Available (DAVA)
3 Destination State Audit (DAUD)
4 SS7 Network Congestion (SCON)
5 Destination User Part Unavailable (DUPU)
6 SCCP Management (SCMG)
7 - 127 Reserved by the IETF
128 - 255 Reserved for IETF-Defined Message Class Extensions
Application Server Process Maintenance (ASPM) Messages
0 Reserved
1 ASP Up (UP)
2 ASP Down (DOWN)
3 Heartbeat (BEAT)
4 ASP Up Ack (UP ACK)
5 ASP Down Ack (Down ACK)
6 Heartbeat Ack (BEAT ACK)
7 - 127 Reserved by the IETF
128 - 255 Reserved for IETF-Defined Message Class Extensions
ASP Traffic Maintenance (ASPTM) Messages
0 Reserved
1 ASP Active (ACTIVE)
2 ASP Inactive (INACTIVE)
3 ASP Active Ack (ACTIVE ACK)
4 ASP Inactive Ack (INACTIVE ACK)
5 - 127 Reserved by the IETF
128 - 255 Reserved for IETF-Defined Message Class Extensions
Connectionless Messages
0 Reserved
1 Connectionless Data Transfer (CLDT)
2 Connectionless Data Response (CLDR)
3 - 127 Reserved by the IETF
128 - 255 Reserved for IETF-Defined Message Class Extensions
Connection-Oriented Messages
0 Reserved
1 Connection Request (CORE)
2 Connection Acknowledge (COAK)
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
3 Connection Refused (COREF)
4 Release Request (RELRE)
5 Release Complete (RELCO)
6 Reset Confirm (RESCO)
7 Reset Request (RESRE)
8 Connection Oriented Data Transfer (CODT)
9 Connection Oriented Data Acknowledge (CODA)
10 Connection Oriented Error (COERR)
11 - 127 Reserved by the IETF
128 - 255 Reserved for IETF-Defined Message Class Extensions
3.1.4 Message Length
The Message Length defines the length of the message in octets,
including the header.
3.1.4 Tag-Length-Value Format
SUA messages consist of a Common Header followed by zero or more
parameters, as defined by the message type. The Tag-Length-Value
(TLV) parameters contained in a message are defined in a Tag-
Length-Value format as shown below.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Parameter Tag | Parameter Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ \
/ Parameter Value /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameter Tag: 16 bits (unsigned integer)
Tag field is a 16-bit identifier of the type of parameter. It
takes a value of 0 to 65534.
Parameter Length: 16 bits (unsigned integer)
The Parameter Length field contains the size of the parameter in
bytes, including the Parameter Tag, Parameter Length, and
Parameter Value fields. The Parameter Length does not include any
padding bytes.
Parameter Value: variable-length.
The Parameter Value field contains the actual information to be
transferred in the parameter.
The total length of a parameter (including Tag, Parameter Length
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
and Value fields) MUST be a multiple of 4 bytes. If the length of
the parameter is not a multiple of 4 bytes, the sender pads the
Parameter at the end (i.e., after the Parameter Value field) with
all zero bytes. The length of the padding is NOT included in the
parameter length field. A sender should NEVER pad with more than
3 bytes. The receiver MUST ignore the padding bytes.
3.2 SUA Connectionless Messages
The following section describes the SUA Connectionless transfer
messages and parameter contents. The general message format
includes a Common Message Header together with a list of zero or
more parameters as defined by the Message Type. All Message Types
can have attached parameters.
3.2.1 Connectionless Data Transfer
This message transfers data between one SUA to another.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0105 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0102 | Parameter Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ Source Address /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0103 | Parameter Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ destination address /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0003 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ data /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameters
Flags Mandatory
Source Address Mandatory
Destination Address Mandatory
Data Mandatory
Implementation note:
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
This message covers the following SCCP messages: unitdata (UDT),
extended unitdata (XUDT), long unitdata (LUDT).
3.2.2 Connectionless Data Response
This message is used as a response message by the peer and/or report
errors.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0105 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0109 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SCCP Error Cause |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0102 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ Source Address /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0103 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ destination address /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0003 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ data /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameters
Flags Mandatory
SCCP Error Cause Mandatory
Source Address Mandatory
Destination Address Mandatory
Data Optional
Implementation note:
This message covers the following SCCP messages: long unitdata
service (LUDTS), unitdata service (UDTS), extended unitdata service
(XUDTS).
3.3 Connection Oriented Messages
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
3.3.1 Connection Oriented Data Transfer
This message transfers data between one SUA to another for
connection oriented service.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0107 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| destination reference number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0003 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ data /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0105 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0101 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameters
Destination Reference Number Mandatory
Data Mandatory
Flags Mandatory *1
Sequence number Mandatory *2
NOTE *1: Mandatory for representing DT1 message.
NOTE *2: Mandatory when CODT message maps a DT2 message.
Otherwise, the parameter is not be present.
Implementation note:
This message covers the following SCCP messages: data form 1 (DT1),
data form 2 (DT2), expedited data (ED).
3.3.2 Connection Oriented Data Acknowledge
This message is used to acknowledge receipt of data by the peer.
This message is used only with protocol class 3.
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0107 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| destination reference number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x010F | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Receive Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x010C | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Credit |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameters
Destination Reference Number Mandatory
Receive Sequence number Mandatory *1
Credit Mandatory *1
NOTE *1: Mandatory when representing Data Acknowledgement (AK).
Implementation note:
This message covers the following SCCP messages: data
acknowledgement (AK), expedited data acknowledgement (EA).
3.3.3 Connect Request
This message is used for establishing a signaling connection between
two peer endpoints. This is used for connection oriented service.
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0105 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0106 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source Reference Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0103 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ Destination Address /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0102 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ Source Address /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x010C | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Credit |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0003 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ Data /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameters
Flags Mandatory
Source Reference Number Mandatory
Destination Address Mandatory
Source Address Optional
Credit Optional
Data Optional
3.3.4 Connection Acknowledge
This message is used to acknowledge a connection request between two
peer endpoints.
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0107 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Destination Reference Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0106 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source Reference Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0105 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x010C | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Credit |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0103 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ Destination Address /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0003 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ Data /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameters
Destination Reference Number Mandatory
Source Reference Number Mandatory
Flags Mandatory
Credit Optional
Destination Address Optional *1
Data Optional
NOTE *1: Destination Address parameter will be present in case
that the received CORE message conveys the Source
Address parameter.
Implementation note:
This message covers the following SCCP message: connection confirm
(CC).
3.3.5 Connection Refused (COREF)
This message is used to refuse a connection request between two peer
endpoints.
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0107 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Destination Reference Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0109 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SCCP Error Cause |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0103 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ Destination Address /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0001 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ Data /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameters
Destination Reference Number Mandatory
SCCP Error Cause Mandatory
Destination Address Optional *1
Data Optional
Note *1: Destination Address parameter will be present in case
that the received CORE message conveys the Source
Address parameter.
3.3.6 Release Request
This message is used to request a signaling connection between two
peer endpoints be released. All associated resources can then be
released.
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0107 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| destination reference number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0106 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| source reference number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0104 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Return Cause |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0105 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0003 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ data /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameters
Destination Reference Number Mandatory
Source Reference Number Mandatory
Return Cause Mandatory
Flags Optional
Data Optional
Implementation Note:
This message covers the following SCCP message: connection refused
(CREF).
3.3.7 Release Complete
This message is used to acknowledge the release of a signaling
connection between two peer endpoints. All associated resources
should be released.
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0107 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| destination reference number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0106 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| source reference number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameters
Destination Reference Number Mandatory
Source Reference Number Mandatory
3.3.8 Reset Request
This message is used to indicate that the sending SCCP/SUA wants to
initiate a reset procedure (re-initialization of sequence numbers)
the peer endpoint.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0107 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| destination reference number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0106 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| source reference number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0109 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SCCP Error Cause |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameters
Destination Reference Number Mandatory
Source Reference Number Mandatory
SCCP Error Cause Mandatory
3.3.9 Reset Confirm
This message is used to confirm the Reset Request.
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0107 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| destination reference number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0106 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| source reference number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameters
Destination Reference Number Mandatory
Source Reference Number Mandatory
3.3.10 Connection Oriented Error (COERR)
The COERR message is sent when an invalid value is found in an
incoming message.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0107 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| destination reference number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0109 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SCCP Error Cause |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameters
Destination Reference Number Mandatory
SCCP Error Cause Mandatory
Implementation Note:
This message covers the following SCCP message: Protocol data unit
error (ERR)
3.4 SS7 Signaling Network Management Messages
3.4.1 Destination Unavailable
The DUNA message is sent from the SG to all concerned ASPs to
indicate that the SG has determined that an SS7 destination is
unreachable. The SUA-User at the ASP is expected to stop traffic to
the affected destination through the SG initiating the DUNA.
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
The format for DUNA Message parameters is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0001 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Network Appearance |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0005 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ Affected Point Code /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0004 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ info string /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameters
Affected Point Code Mandatory
Network Appearance Optional
Info String Optional
3.4.2 Destination Available
The DAVA message is sent from the SG to all concerned ASPs to
indicate that the SG has determined that an SS7 destination is now
reachable. The ASP SUA-User protocol is expected to resume traffic
to the affected destination through the SG initiating the DAVA.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0001 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Network Appearance |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0005 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ Affected Point Code /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0004 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ info string /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameters
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
Affected Point Code Mandatory
Network Appearance Optional
Info String Optional
3.4.3 Destination State Audit
The DAUD message can be sent from the ASP to the SG to query the
availability state of the SS7 routes to an affected destination. A
DAUD may be sent periodically after the ASP has received a DUNA,
until a DAVA is received. The DAUD can also be sent when an ASP
recovers from isolation from the SG.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0001 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Network Appearance |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0005 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ Affected Point Code /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0004 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ info string /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameters
Affected Point Code Mandatory
Network Appearance Optional
Info String Optional
3.4.4 SS7 Network Congestion
The SCON message can be sent from the SG to all concerned ASPs to
indicate that the congestion level in the SS7 network to a specified
destination has changed.
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0001 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Network Appearance |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0010 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Congestion Level |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0005 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ Affected PC(s) \
/ /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0004 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ info string /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameters
Network Appearance Optional
Congestion Level Mandatory
Affected PCs Mandatory
Info String Optional
3.4.5 Destination User Part Unavailable
The DUPU message is used by an SG to inform an ASP that a remote
peer SUA-User User Part at an SS7 node is unavailable.
The format for DUPU Message parameters is as follows:
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0001 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Network Appearance |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0005 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ Affected Point Code /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0009 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Cause/User |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0004 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ info string /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameters
Network Appearance Optional
Affected Point Code Mandatory Note *1
Cause/User Mandatory
Info String Optional
3.4.6 SCCP Management Message
The SCMG message is sent between SUA Peers to indicate status of
subsystems. Only one SCMG message type can be sent per message.
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x010D | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SCMG Message Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x010E | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SMI | Subsystem |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0005 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ Affected PC /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0108 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| congestion level |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0004 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ INFO String \
\ /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameters
SCMG Message Type Mandatory
Subsystem/SMI Mandatory
Affected Point Code Mandatory *1
Congestion Level Mandatory *2
Info String Optional
Note *1: In the SCMG message, the Affected Point Code Parameter
MUST contain, at most, a single Affected Point Code.
Note *2: When the SCMG Message Type is SSC, then the Congestion
Level parameter is Mandatory, otherwise it is optional.
3.5 Application Server Process Maintenance Messages
3.5.1 ASP Up (ASPUP)
The ASP UP (ASPUP) message is used to indicate to a remote SUA peer
that the Adaptation layer is up and running.
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x010A | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ASP Capabilities |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0004 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ info string /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameters
ASP Capabilities Optional
Info String Optional
3.5.2 ASP Up Ack (UPACK)
The ASP UP Ack message is used to acknowledge an ASP-Up message
received from a remote SUA peer.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x010A | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ASP Capabilities |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0004 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ info string /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameters
ASP Capabilities Optional
Info String Optional
3.5.3 ASP Down (ASPDN)
The ASP Down (ASPDN) message is used to indicate to a remote SUA
peer that the adaptation layer is not running.
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0002 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Cause Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0004 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ info string /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameters
Cause Code Mandatory
Info String Optional
3.5.4 ASP Down Ack (DNACK)
The ASP DOWN Ack message is used to acknowledge an ASP-Down message
received from a remote SUA peer.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0002 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Cause Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0004 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ info string /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameters
Reason Mandatory
Info String Optional
3.5.5 Heartbeat (BEAT)
The Heartbeat message is optionally used to ensure that the SUA
peers are still available to each other.
The format for the BEAT message is as follows:
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 8 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ Heartbeat Data /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameters
Heartbeat Data Optional
3.5.6 Heartbeat Ack (BEAT ACK)
The Heartbeat ACK message is sent in response to a BEAT message. A
peer MUST send a BEAT ACK in response to a BEAT message. It includes
all the parameters of the received Heartbeat message, without any
change.
The format for the BEAT ACK message is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 8 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ Heartbeat Data /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameters
Heartbeat Data Optional
3.6 ASP Traffic Maintenance Messages
3.6.1 ASP Active (ASPAC)
The ASPAC message is sent by an ASP to indicate to a remote SUA peer
that it is Active and ready to process signaling traffic for a
particular Application Server
The format for the ASPAC message is as follows:
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x000D | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Status Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0006 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ Routing Context /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0004 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ INFO String /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameters
Status Type Mandatory
Routing Context Optional
INFO String Optional
3.6.2 ASP Active Ack
The ASPAC Ack message is used to acknowledge an ASP-Active message
received from a remote SUA peer.
The format for the ASPAC Ack message is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x000D | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Status Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0006 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ Routing Context /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0004 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ INFO String /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameters
Status Type Mandatory
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
Routing Context Optional
INFO String Optional
The Status Type field in the ASPAC Ack message should contain the
type as the ASPAC message to which the message is acknowledging.
3.6.3 ASP Inactive (ASPIA)
The ASPIA message is sent by an ASP to indicate to a remote SUA peer
that it is no longer processing signaling traffic within a
particular Application Server.
The format for the ASPIA message parameters is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x000D | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Status Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0006 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ Routing Context /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0004 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ INFO String /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameters
Status Type Mandatory
Routing Context Optional
INFO String Optional
A node that receives an ASPIA with an incorrect Type for a
particular Routing Context will respond with an Error Message
(Cause: Invalid Traffic Handling Mode).
3.6.4 ASP Inactive Ack
The ASPIA Ack message is used to acknowledge an ASP-Inactive message
received from a remote SUA peer.
The format for the ASPIA Ack message is as follows:
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x000D | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Status Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0006 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ Routing Context /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0004 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ INFO String /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameters
Status Type Mandatory
Routing Context Optional
INFO String Optional
The Status Type field in the Ack message should contain the type as
the ASPIA message to which the message is acknowledging.
3.7 Management Messages
These messages are used for managing SUA and the representations of
the SCCP subsystems in the SUA layer.
3.7.1 Error (ERR)
The ERR message is sent between two SUA peers to indicate an error
situation. The Data parameter is optional, possibly used for error
logging and/or debugging.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x000C | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Error Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0007 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ Diagnostic Info /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameters
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
Error Code Mandatory
Diagnostic Info Optional
3.7.2 Notify (NTFY)
The Notify message used to provide an autonomous indication of SUA
events to an SUA peer.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x000D | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Status Type / Status ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0006 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ Routing Context /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0004 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ info string /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The NTFY message contains the following parameters:
Parameters
Status Type Mandatory
Routing Context Optional
Info String Optional
3.8 Common Parameters
These TLV parameters are common across the different adaptation
layers.
Parameter Name Parameter ID
============== ============
Network Appearance 0x0001
Cause Code 0x0002
Data 0x0003
Info String 0x0004
Affected Point Code 0x0005
Routing Context 0x0006
Diagnostic Info 0x0007
Heartbeat Data 0x0008
Cause/User 0x0009
Congestion 0x000A
Not used 0x000B
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Not used 0x000C
Status Type / Status ID 0x000D
3.8.1 Network Appearance
The Network Appearance parameter identifies the SS7 network context
for the message, for the purposes of logically separating the
signaling traffic between the SG and the Application Server
Processes over common SCTP Associations. An example is where an SG
is logically partitioned to appear as an element in four different
national SS7 networks. A Network Appearance implicitly defines the
SS7 Destination Point Code used, the SS7 Network Indicator value and
SCCP/SCCP-User protocol type/variant/version used within the SS7
network partition. Where an SG operates in the context of a single
SS7 network, or individual SCTP associations are dedicated to each
SS7 network appearance, the Network Appearance parameter is not
required.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0001 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| network appearance |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
In an SSNM message, the Network Appearance parameter defines the
format of the Affected PC(s) in the Affected Destination parameter.
The PC point code length (e.g., 14-, 16-, or 24-bit) and sub-field
definitions (e.g., ANSI 24-bit network/cluster/member, ITU-
international 14-bit zone/region/signal_point, many national field
variants, ...) are fixed within a particular Network Appearance.
Where an SG operates in the context of a single SS7 network, or
individual SCTP associations are dedicated to each SS7 network
context, the Network Appearance parameter is not required and the
format of the Affected PC(s) is understood implicitly.
The format of the Network Appearance parameter is an integer, the
values of which are assigned according to network operator policy.
The values used are of local significance only, coordinated between
the SG and ASP.
Where the optional Network Appearance parameter is present, it must
be the first parameter in the message as it defines the format of
the Affected PCs in the Affected Destination parameter.
3.8.2 Cause Code
The Cause Code parameter indicates the reason that the remote SUA
adaptation layer is unavailable. The valid values for Reason are
shown in the following table.
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
Value Description
0x1 Processor Outage
0x2 Management Inhibit
3.8.3 Data
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0003 | length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ data /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3.8.4 Info String
The INFO String parameter can carry any meaningful 8-BIT ASCII
character string along with the message. Length of the INFO String
parameter is from 0 to 255 characters. No procedures are presently
identified for its use but the INFO String may be used by Operators
for debugging purposes.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0004 | length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ info string /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3.8.5 Affected Point Code
The Affected Point Code parameter contains one or more Affected
Destination Point Codes, each a three-octet parameter to allow for
4-, 16- and 24-bit binary formatted SS7 Point Codes. Affected Point
codes that are less than 24-bits, are padded on the left to the 24-
bit boundary.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0005 | length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Mask | Affected PC 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ . . . /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
The encoding is shown below for ANSI and ITU Point Code examples.
ANSI 24-bit Point Code:
0 1 2 3-->
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Mask | Network | Cluster | Member |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|MSB-----------------------------------------LSB|
ITU 14-bit Point Code:
0 1 2 3-->
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Mask |0 0 0 0 0 0 0 0 0 0|Zone | Region | SP |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|MSB--------------------LSB|
It is optional to send an Affected Pointe Code parameter with more
than one Affected PC but it is mandatory to receive it. All the
Affected PCs included must be within the same Network Appearance.
Including multiple Affected PCs may be useful when reception of an
management message or a linkset event simultaneously affects the
availability status of a list of destinations at an SG.
Mask: 8-bits
The Mask parameter is used to identify a contiguous range of
Affected Destination Point Codes, independent of the point code
format. Identifying a contiguous range of Affected PCs may be
useful when reception of an MTP3 management message or a linkset
event simultaneously affects the availability status of a series of
destinations at an SG.
The Mask parameter is an integer representing a bit mask that can be
applied to the related Affected PC field. The bit mask identifies
how many bits of the Affected PC field is significant and which are
effectively "wildcarded". For example, a mask of "8" indicates that
the last eight bits of the PC is "wildcarded". For an ANSI 24-bit
Affected PC, this is equivalent to signaling that all PCs in an ANSI
Cluster are unavailable. A mask of "3" indicates that the last
three bits of the PC is "wildcarded". For a 14-bit ITU Affected PC,
this is equivalent to signaling that an ITU Region is unavailable.
3.8.6 Routing Context
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0006 | length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ Routing Context /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The Routing Context parameter contains (a list of) integers indexing
the Application Server traffic that the sending ASP is configured to
receive. There is one-to-one relationship between an index entry
and an AS Name. Because an AS can only appear in one Network
Appearance, the Network Appearance parameter is not required in the
ASPAC message
An Application Server Process may be configured to process traffic
for more than one logical Application Server. From the perspective
of an ASP, a Routing Context defines a range of signaling traffic
that the ASP is currently configured to receive from the SG.
3.8.7 Diagnostic Information
The Diagnostic Information can be used to convey any information
relevant to an error condition, to assist in the identification of
the error condition. In the case of an Invalid Network Appearance,
Adaptation Layer Identifier or Traffic Handling Mode, the Diagnostic
information includes the received parameter. In the other cases,
the Diagnostic information may be the first 40 bytes of the
offending message.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0007 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ Diagnostic Information* /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3.8.8 Heartbeat Data
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 8 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ Heartbeat Data /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
The data field can be used to store information in the heartbeat
message useful to the sending node (e.g. the data field can contain
a time stamp, a sequence number, etc.).
3.8.9 Cause/User
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 9 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Cause | User |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Unavailability Cause field: 16-bits (unsigned integer)
The Unavailability Cause parameter provides the reason for the
unavailability of the SUA-User. The valid values for the
Unavailability Cause parameter are shown in the following table.
0 Unknown
1 Unequipped Remote User
2 Inaccessible Remote User
User Identity field: 16-bits (unsigned integer)
The User Identity describes the specific SUA-User that is
unavailable. Some of the valid values for the User Identity are
shown below.
0 - 2 Reserved by M3UA
3 SCCP/SUA
4 - 10 Reserved by M3UA
3.8.10 Congestion Level
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0010 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Congestion Level |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Congestion Level field: 8-bits (unsigned integer)
The Congestion Level will have two different meanings, depending
upon the message it is received with.
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
For the SCON message, the Congestion Level field, contains one of
the following values, which are associated with a destination point
code:
0 No Congestion or Undefined
1 Congestion Level 1
2 Congestion Level 2
3 Congestion Level 3
The congestion levels are as defined in the national congestion
method in the appropriate MTP recommendation [ITU-MTP], [ANSI-MTP].
For MTP congestion methods that do not employ congestion levels
(e.g., the ITU international method, the parameter is always
"Undefined").
When an SCON is received at the SG, a TFC message is generated into
the SS7 network.
For the SCMG message, the valid values for the Congestion Level
parameter range from 0 to 7, where 0 indicates least congested and 7
indicates most congested.
4.8.11 Error Code
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag =0x000C | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Error Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The Error Code parameter indicates the reason for the Error Message.
The Error parameter value can be one of the following values:
Invalid Version 0x01
Invalid Network Identifier 0x02
Unexpected Message Class 0x03
Invalid Message Type 0x04
Unsupported Traffic Handling Mode 0x05
Unexpected Message 0x06
Protocol Error 0x07
Reserved 0x08
Invalid Stream Identifier 0x09
The "Invalid Version" error would be sent if a message was received
with an invalid or unsupported version. The Error message would
contain the supported version in the Common header. The Error
message could optionally provide the supported version in the
Diagnostic Information area.
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
The "Invalid Interface Identifier" error would be sent by a SG if
an ASP sends a message with an invalid (unconfigured) Interface
Identifier value.
The "Unsupported Traffic Handling Mode" error would be sent by a SG
if an ASP sends an ASP Active with an unsupported Traffic Handling
Mode. An example would be a case in which the SG did not support
load-sharing.
The "Unexpected Message" error would be sent by an ASP if it
received a message while it was in the Inactive state.
The "Protocol Error" error would be sent for any protocol anomaly
(i.e. a bogus message).
The "Invalid Stream Identifier" error would be sent if a message
was received on an unexpected SCTP stream (i.e. a stream that did
not have an Interface Identifier associated with it).
The "Unexpected Message Class" error would be sent if a message with
an unexpected or unsupported Message Class is received.
The optional Diagnostic information can be any information germane
to the error condition, to assist in identification of the error
condition. To enhance debugging, the Diagnostic information could
contain the first 40 bytes of the offending message.
The Cause parameter can be one of the following values:
Invalid Version 0x1
Invalid Network Appearance 0x2
Invalid Adaptation Layer Identifier 0x3
Invalid Message Type 0x4
Invalid Traffic Handling Mode 0x5
Unexpected Message Type 0x6
Protocol Error 0x7
Invalid Routing Context 0x8
Unsupported Message Type 0x9
3.8.12 Status
The Status Type parameter identifies the type of the status that is
being notified.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x000D | length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Status Type | Status ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
The valid values are shown in the following table.
1 Application Server state change (AS_State_Change)
2 Other
The Status Id parameter identifies the status that is being
notified. The valid values are shown in the following table.
If the Status Type is AS_STATE_CHANGE
If the Status Type is AS_State_Change the following Status
Information values are used:
1 Application Server Down (AS_Down)
2 Application Server Up (AS_Up)
3 Application Server Active (AS_Active)
4 Application Server Pending (AS_Pending)
5 Alternate ASP Active
6 Insufficient ASPs
If the Status Type is Other, then the following Status Information
values are defined:
1 Insufficient ASP resources active in AS
This notification is not based on the SG reporting the state change
of an ASP or AS. For the value defined the SG is indicating to an
ASP(s) in the AS that another ASP is required in order to handle the
load of the AS.
3.9 SUA-Specific parameters
These TLV parameters are specific to the SUA protocol.
Parameter Name Parameter ID
============== ============
Sequence Number 0x0101
Source Address 0x0102
Destination Address 0x0103
Return Cause 0x0104
Flags 0x0105
Source Reference Number 0x0106
Destination Reference Number 0x0107
Reserved 0x0108
SCCP Error 0x0109
ASP Capabilities 0x010A
Status 0x010B
Credit 0x010C
Not used 0x010D
SMI / Subsystem 0x010E
Loughney, et al. [Page 46]
Internet Draft SS7 SCCP-User Adaptation Layer November 24, 2000
3.9.1 Sequence Number
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 0x0101 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| spare | Rec Seq Num | Sent Seq Num |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
It is used exclusively for protocol class 3 to number each DT
message sequentially for the purpose of flow control, sequence
numbering and segmenting and reassembly.
It is used to number each DT message sequentially for the purpose of
flow control. It contains the received as well as the sent sequence
number, P(R) and P(S) in Q.713.
As such it can be used to acknowledge the receipt of data transfers
from the peer in case of protocol class 3.
Sent Sequence Number is one octet and is coded as follows:
Bits 8-2 are used to indicate the Send Sequence Number P(S).
Bit 1 of octet 1 is spare.
Receive Sequence Number is one octet, and is coded as follows:
Bits 8-2 are used to indicate the Receive Sequence Number
P(R).
Bit 1 is used for the more data indication, as follows:
0 no more data
1 more data.
3.9.2 Source Address (=CLG)
0 1 |
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