SS7 / SIGTRAN

Trillium Signaling System 7 (SS7) software source code solutions enhance and extend the signaling capabilities of next-generation telecommunications network devices by enabling superior availability, performance and scalability.

SS7 is a suite of global telecommunications protocol standards that define the procedures by which network elements within the Public Switched Telephone Network (PSTN) exchange control information over digital signaling links for setting up, managing, and tearing down wireline and wireless calls.

Signaling System 7 is also the protocol that defines the procedures to transport and process database queries necessary for providing today's advanced intelligent network (AIN) features and services. SS7 is increasingly being used to bridge the PSTN with next-generation Internet Protocol (IP) and 3G Wireless networks.

Designed to improve network operation and to provide enhanced services, SS7 carries packetized data to form a low-delay, highly secure and reliable infrastructure that supports voice transport and services over the circuit-switched network.

The SS7 standard has been extended for multiple country-specific variations, such as the American National Standards Institute (ANSI) and Telcordia Technologies (formerly Bellcore) standards within North America, and the European Telecommunications Standards Institute (ETSI) standard in Europe.

Broadband standards have been defined to support transferring Signaling System 7 messages over ATM to take advantage of the higher speeds and Quality of Service (QoS) available in broadband networks. The SS7-over-IP standards support transporting SS7 messages over IP-based networks, which enables seamless convergence and inter-working of PSTN and IP protocols within a unified architecture.

SS7 Stack Diagram

SS7 Network Architecture

SS7 Solutions

The Trillium SS7 product line includes the following protocol layers:

Intelligent Network Application Protocol (INAP)

• Capability Set 1 (CS1), as defined by the ITU, ETSI, and the Generic Requirement (GR) standards of the Telcordia Advanced Intelligent Network (AIN)
• The interaction between the SSF, SCF, Specialized Resource Function (SRF), and the Service Data Function (SDF)

ISDN User Part (ISUP)

• The signaling protocol to establish, maintain and release circuit-switched network connections across an SS7 network; can act as originating, destination or intermediate exchange
• ITU-T, Telcordia (formally Bellcore), ANSI, Singapore, Q.767, ETSI, FTZ, Russia, Italy, NTT (Japan), and other variants

Mobile Application Part (MAP)

• Used by the Mobile Switching Center (MSC), Serving GPRS Support Node (SGSN), and Gateway GPRS Support Node (GGSN) in wireless networks to query the Home Location Register (HLR) or Visitor Location Register (VLR) to determine and/or verify subscriber services

MTP1

• Defines the physical and functional characteristics of the digital signaling link

MTP2

• Reliable transfer of signaling messages over signaling links
• ITU-T, ANSI, TTC (Japan), NTT (Japan), China, and other variants

MTP3

• Broadband and narrowband signaling traffic management, signaling link and route management
• Functionality as an SSP or STP; Direct inter-working with Trillium Q.2140 ATM
  • ITU-T, ANSI, TTC (Japan), NTT (Japan), Singapore, China, B-ICI, and other variants
• Connection-oriented and/or connection-less services (Class 0, 1, 2, and 3) for transferring data across an SS7 network
  • ITU-T, ANSI, and China variants
• End-to-end, connectionless network service protocol between transaction capability users across an SS7 network
• An ASN.1 encoding/decoding engine to encode/decode all operation codes and dialog parameters
  • ITU-T, ANSI, ETSI, and TTC (Japan) variants
• Convergence functions necessary to map the SS7 MTP Level 3 protocol to the ATM Q.SAAL protocol
• ITU-T Q.2140, B-ISDN - ATM Adaptation Layer - SSCF at NNI and Q.2110, B-ISDN - ATM Adaptation Layer - SSCOP
• Establishing, maintaining and releasing circuit-switched network connections across an SS7 network; can act as the originating, destination, or intermediate exchange
  • ITU-T and China variants
• The Motorola MC68360 SCC Driver portable software product supports the HDLC and SS7 interfaces. It can be directly used with Trillium LAPB, LAPD, Frame Relay, and MTP2 products.
• The Motorola MPC8260 Driver and MPC860 Driver portable software product supports the HDLC, AAL5, and SS7 interfaces. It can be directly used with the Trillium LAPB, LAPD, Frame Relay, ATM, and MTP2 products.

Signaling Connection Control Part (SCCP)

Transaction Capabilities Application Part (TCAP)

Q.2140

Telephone User Part (TUP)

Drivers

Trillium SS7 Software

• CAP - CAMEL Application Part
• INAP - Intelligent Network Application Part
• ISUP - ISDN User Application Part
• MAP - Mobile Application Part
• MAP IS-41 - Mobile Application Part IS-41
• MTP2 - Message Transfer Part Level 2
• MTP3 - Message Transfer Part Level 3
• MTP3-B - MTP Level3 Broadband
• Q.2140 - MTP3 / Q.SAAL Convergence Layer
• SCCP - Signaling Connection Control Part
• TCAP - Transaction Capability Application Part