SIGTRAN is the name, derived from ''signaling transport'', of the former
Internet Task Force (I) working group that produced specifications for a family of protocols that provide reliable
datagram
A datagram is a basic transfer unit associated with a packet-switched network. Datagrams are typically structured in header and payload sections. Datagrams provide a connectionless communication service across a packet-switched network. The del ...
service and user layer adaptations for
Signaling System and
ISDN
Integrated Services Digital Network (ISDN) is a set of communication standards for simultaneous digital transmission of voice, video, data, and other network services over the digitalised circuits of the public switched telephone network. Work ...
communications protocols
A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information via any kind of variation of a physical quantity. The protocol defines the rules, syntax, semantics and synchroniza ...
. The SIGTRAN protocols are an extension of the SS7 protocol family. It supports the same application and call management paradigms as SS7 but uses an
Internet Protocol
The Internet Protocol (IP) is the network layer communications protocol in the Internet protocol suite for relaying datagrams across network boundaries. Its routing function enables internetworking, and essentially establishes the Internet.
...
(IP) transport called
Stream Control Transmission Protocol (SCTP), instead of TCP or UDP. Indeed, the most significant protocol defined by the SIGTRAN group is SCTP, which is used to carry
PSTN
The public switched telephone network (PSTN) provides infrastructure and services for public telecommunication. The PSTN is the aggregate of the world's circuit-switched telephone networks that are operated by national, regional, or local teleph ...
signaling over IP.
The SIGTRAN group was significantly influenced by
telecommunications
Telecommunication is the transmission of information by various types of technologies over wire, radio, optical, or other electromagnetic systems. It has its origin in the desire of humans for communication over a distance greater than that fe ...
engineers intent on using the new protocols for adapting
IP networks to the
PSTN
The public switched telephone network (PSTN) provides infrastructure and services for public telecommunication. The PSTN is the aggregate of the world's circuit-switched telephone networks that are operated by national, regional, or local teleph ...
with special regard to signaling applications. Recently, SCTP is finding applications beyond its original purpose wherever reliable datagram service is desired.
SIGTRAN has been published in RFC 2719, under the title ''Framework Architecture for Signaling Transport''. RFC 2719 also defines the concept of a ''
signaling gateway
A signaling gateway is a network component responsible for transferring signaling messages (i.e. information related to call establishment, billing, location, short messages, address conversion, and other services) between Common Channel Signalin ...
'' (SG), which converts Common Channel Signaling (CCS) messages from SS7 to SIGTRAN. Implemented in a variety of network elements including
softswitch
A softswitch (''software switch'') is a call-switching node in a telecommunications network, based not on the specialized switching hardware of the traditional telephone exchange, but implemented in software running on a general-purpose computing ...
es, the SG function can provide significant value to existing common channel signaling networks, leveraging investments associated with SS7 and delivering the cost/performance values associated with IP transport.
SIGTRAN protocols
The SIGTRAN family of protocols includes:
*
Stream Control Transmission Protocol (SCTP), RFC 2960, RFC 3873, RFC 4166, RFC 4960.
*
ISDN
Integrated Services Digital Network (ISDN) is a set of communication standards for simultaneous digital transmission of voice, video, data, and other network services over the digitalised circuits of the public switched telephone network. Work ...
User Adaptation (IUA), RFC 4233, RFC 5133.
*
Message Transfer Part
The Message Transfer Part (MTP) is part of the Signaling System 7 (SS7) used for communication in Public Switched Telephone Networks. MTP is responsible for reliable, unduplicated and in-sequence transport of SS7 messages between communication ...
2 (MTP) User Peer-to-Peer Adaptation Layer (M2PA), RFC 4165.
*
Message Transfer Part
The Message Transfer Part (MTP) is part of the Signaling System 7 (SS7) used for communication in Public Switched Telephone Networks. MTP is responsible for reliable, unduplicated and in-sequence transport of SS7 messages between communication ...
2 User Adaptation Layer (M2UA), RFC 3331.
*
Message Transfer Part
The Message Transfer Part (MTP) is part of the Signaling System 7 (SS7) used for communication in Public Switched Telephone Networks. MTP is responsible for reliable, unduplicated and in-sequence transport of SS7 messages between communication ...
3 User Adaptation Layer (M3UA), RFC 4666.
*
(SCCP) User Adaptation (SUA), RFC 3868.
*
V5 User Adaptation (V5UA), RFC 3807.
*
DPNSS
The Digital Private Network Signalling System (DPNSS) is a network protocol used on digital trunk lines for connecting to PABX. It supports a defined set of inter-networking facilities.
DPNSS was originally defined by British Telecom. The specif ...
/
DASS2 User Adaption (DUA), RFC 4129
The
Stream Control Transmission Protocol provides the
transport protocol
Transport (in British English), or transportation (in American English), is the intentional movement of humans, animals, and goods from one location to another. Modes of transport include air, land (rail and road), water, cable, pipeline, ...
for SIGTRAN user adaptation layer messages across an IP network. It is described in RFC 3873, RFC 4166 and RFC 4960.
''IUA'' provides an SCTP adaptation layer for the seamless
backhaul o
Q.921user messages and service interface across an IP network. Some users that it supports are
Q.931
ITU-T Recommendation Q.931 is the ITU standard ISDN connection control signalling protocol, forming part of ''Digital Subscriber Signalling System No. 1''. Unlike connectionless systems like UDP, ISDN is connection oriented and uses explicit sign ...
and
QSIG QSIG is an ISDN based signaling protocol for signaling between private branch exchanges (PBXs) in a private integrated services network (PISN). It makes use of the connection-level Q.931 protocol and the application-level ROSE protocol. ISDN "prop ...
. It is specified in RFC 4233.
''V5UA'' provides an SCTP adaptation layer for the seamless backhaul of V5.2 user messages and service interface across an IP network. It is a variation of ''IUA'' and is specified in RFC 3807.
''M2PA'' provides an SCTP adaptation layer for providing an SS7 MTP signaling link over an IP network. It is specified in RFC 4165. The difference between ''M2PA'' and ''M2UA'' is described in section 1.9 of RFC 4165
''M2UA'' provides an SCTP adaptation layer for the seamless backhaul of MTP Level 2 user messages and service interface across an IP network. It is specified in RFC 3331.
''M3UA'' provides an SCTP adaptation layer for the seamless backhaul or peering of MTP Level 3 user messages and service interface across an IP network. It is specified in RFC 4666.
''SUA'' provides an SCTP adaptation layer for the seamless backhaul or peering of Signalling Connection Control Part user messages and service interface across an IP network. It is specified in RFC 3868.
Scheme
Notes
References
*
*
sigtran.org- Archived SIGTRAN website.
*IEC Tutorial
[{{Cite web, url=https://sudoparatech.com/hack-phone-calls-whatsapp-to-read-messages-without-touching-the-user-phoness72019/, title=SS7 Hack phone, last=, first=, date=2019-10-06, website=Sudo Para Tech, language=en-US, url-status=live, archive-url=, archive-date=, access-date=2019-10-16]- IEC SS7 over IP (SIGTRAN) protocols
ead*Sergey Puzankov, Dmitry Kurbatov
How to Intercept a Conversation Held on the Other Side of the Planet 2014-05-22, Positive Hack Days.
*
31c3,
CCC,
and Snort 2018-03-31.
Computer network organizations
Working groups