Message Transfer Part (MTP) Level 3

MTP

Section: OpenSS7 SS7 Stack Devices (4)
Updated: 2007-06-24
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NAME

MTP - Signalling System No. 7 (SS7) Message Transfer Part (MTP)

SYNOPSIS

#include <ss7/mtpi.h>
#include <ss7/mtpi_ioctl.h>

int mtp_stream = open(device, flags);
int mtp_xtistr = t_open(device, flags);
int mtp_socket = socket(PF_SS7, socket_type, SS7PROTO_MTP);

DESCRIPTION

MTP
is an implementation of the Signalling System No. 7 (SS7(4)) Message Transfer Part (MTP) defined in ITU-T Recommendation Q.704[1] and ANSI T1.111.4[2]. MTP provides reliable sequenced or unsequenced delivery of packets over a connectionless transport between two MTP endpoints. MTP provides strong assurances that the data arrives in order on a stream, if requested, and maintains sequencing of packets in the face of most network failures. It generates and checks a per-packet checksum to catch transmission errors. MTP routing routes around link and node failures in the SS7(4) network.

MTP is implemented as a STREAMS(4) multiplexing driver. sl(4), m2ua(4) or m2pa(4) streams are linked under the MTP multiplexing driver using the I_LINK or I_PLINK commands of streamio(7), to provide link services to MTP. Once linked, the streams must be configured using mtp_ioctl(4).

MTP provides the following stream types:

/dev/mtp: This device provides the MTP protocol service interface using the M-primitives of the Message Transfer Part Interface described in mtpi(7).
/dev/mtp-npi-cl, /dev/mtp-npi-co: This device provides the MTP protocol service interface using the N-primitives of the Network Provider Interface[3] npi(7) used for the Message Transfer Part as described in npi_mtp(7). The npi(7) interface provided on a stream opening this device is suitable for use with the sockets(3) library and provides the MTP interface using sockets as described in mtp_socket(7). mtp-npi-cl provides a connectionless N_CLNS network service provider; mtp-npi-co provides a pseudo-connection-oriented N_CONS network service provider.
/dev/mtp-tpi-cl, /dev/mtp-tpi-co: This device provides the MTP protocol service interface using the T-primitives of the Transport Provider Interface[4] tpi(7) used for the Message Transfer Part as described in tpi_mtp(7). The tpi(7) interface provided on a stream opening this device is suitable for use with the xnet(3) or xti(3) library and provides the MTP interface using XTI as described in xti_mtp(3). mtp-tpi-cl provides a connectionless N_CLNS transport service provider; mtp-tpi-co provides a pseudo-connection-oriented N_CONS transport service provider.

MTP provides two socket types used by the sockets(3) library socket(3) call. MTP provides sockets in the protocol family PF_SS7 using the protocol number SS7PROTO_MTP. The socket_type argument can be one of the following:

SOCK_RDM: Provides a connectionless datagram service with reliable delivery including retransmission. Message boundaries are preserved. This socket uses the underlying /dev/mtp-tpi-cl transport service provider.
SOCK_SEQPACKET: Provides a pseudo-connection-oriented packet service with reliable delivery including retransmission. Message boundaries are preserved. Messages can be sent and received in order, if requested. This socket uses the underlying /dev/mtp-tpi-co transport service provider.

The following entries in /etc/protosw provide the information necesary for socksys(4) to use these devices:

PF_SS7	SOCK_RDM	SS7PROTO_MTP	/dev/mtp-tpi-cl	tpi	clts
PF_SS7	SOCK_SEQPACKET	SS7PROTO_MTP	/dev/mtp-tpi-co	tpi	cots

For additional information, see protosw(5).

IOCTLS

All interface support a set of management IO controls using ioctl(2) system calls on the mtp_stream, mtp_xtistr or mtp_socket. These management controls are documented in mtp_ioctl(4).

FILES

<ss7/mtpi.h>, <ss7/mtpi_ioctl.h>, <sys/npi.h>, <sys/npi_ss7.h>, <sys/npi_mtp.h>, <sys/tpi.h>, <sys/tpi_ss7.h>, <sys/tpi_mtp.h>, <xti.h>, <xti_mtp.h>.

VERSIONS

The MTP interface is specific to the OpenSS7 SS7 stack. This is Version 2 of the interface.

REFERENCES

[1]: ITU-T Recommendation Q.704, Message Transfer Part --- Signalling Network Functions and Messages,March 1993,(Geneva),ITU,ITU-T Telecommunication Standardization Sector of ITU. (Previously "CCITT Recommendation")
[2]: ANSI T1.111, Signalling System No. 7 --- Message Transfer Part,1992,ANSI,American National Standards Institute.
[3]: NPI Revision 2.0.0, Network Provider Interface (NPI) Specification,No.Draft 2,August 17, 1992,(Parsippany, New Jersey),UNIXInternational,Inc.,UNIX International Press. <http://www.openss7.org/docs/npi.pdf>
[4]: TPI Revision 2.0.0, Transport Provider Interface (TPI) Specification,No.Draft 2,1999,(Parsippany, New Jersey),OpenGroup,Open Group Publication. <http://www.opengroup.org/onlinepubs/>
[5]: TTC Standard JT-Q)704, Message Transfer Part --- Signalling Network Functions and Messages,April 28, 1992,(Japan),TTC,Telecommunication Technology Committee (TTC).

Trademarks mentioned are the property of their owners.

IDENTIFICATION

OpenSS7 SS7 Stack: Package strss7 version 0.9a.7 released 2007-06-24.

This document was created by man2html, using the manual pages.
Time: 06:54:46 GMT, July 30, 2008