SIGTRAN

Course Overview

Signalling Transport (SIGTRAN) provides an architecture and protocol suite for the transport of real-time signalling information of Internet Protocol (IP) networks. With the growing interest in offering voice services over IP networks, an in-depth knowledge of SIGTRAN operation has become essential for those involved in modern IP network operation.

This comprehensive course provides students with a full description of SIGTRAN, its operation, procedures and the protocols it employs. Opening with an overview of the importance of SIGTRAN in modern telecommunications networks and the benefits it brings, the course then moves on to look in detail at the protocols essential to SIGTRAN working. Section 2 looks at the Stream Control Transmission Protocol (SCTP), and Section 3 takes a look at SIGTRAN common elements. Sections 4 to 7 look at further protocols: the MTP2 Peer-to-Peer Adaptation (M2PA), MTP2 User Adaptation (M2UA), MTP3 User Adaptation (M3UA) and SCCP User Adaptation (SUA).

Audience

This course is primarily designed for engineers involved with the convergence of traditional telecommunications networks and Next Generation Networks (NGN) or softswitching who require an understanding of the solutions available for transporting SS7 over IPbased networks. This course is also very useful for engineers and scientists working in related areas. This includes those working within Government security or forensic work, service development, technical support staff and those in technical management roles.

Skills Gained

On completion of this course the student will be able to:

• list potential benefits of transporting SS7 signalling over an IP-based network
• describe the protocols used to implement SS7 over IP
• identify the services and functions provided by SCTP
• discuss security aspects related to the use of SCTP and TCP
• identify the common elements shared by all SIGTRAN user and peer adaptation layers and identify the SIGTRAN architectural models
• explain the peer-to-peer nature of the SIGTRAN layers and how they interwork with the client-server model employed by SCTP
• outline the fields that make up the SIGTRAN common header and the range of message classes the common header employs
• describe the operation of M2PA and identify situations in which M2PA may be used
• describe the operation of M2UA and identify situations in which M2UA may be used
• describe the operation of M3UA and identify situations in which M3UA may be used
• describe the operation of SUA and identify situations in which SUA may be used
• discuss routing procedures used in association with the support of SCCP connectionless and connection-oriented services

Prerequisites

Familiarity with the PSTN architecture and SS7 signalling protocols, particularly MTP and SCCP, together with some knowledge of the TCP/IP protocol suite.

Course Outline

Signalling Transport (SIGTRAN) Overview

• Voice over IP (VoIP) evolution
• Potential SS7 and IP interworking scenarios
• Softswitch functional entities for VoIP
• SIGTRAN layer
• User adaptation layer options
• Realization of SIGTRAN
• Stream Control Transmission Protocol (SCTP)
• Circuit-related and non-circuit-related scenarios
• Circuit-related SIGTRAN message flows

Stream Control Transmission Protocol (SCTP)

• SCTP service implementation
• SCTP association mapping
• Initiation State Model
• SCTP message flows
• Multihoming
• Retransmit Timeout (RTO)
• SCTP and Network Address Translation (NAT)
• Typical SCTP implementation data
• SCTP and TCP security issues
• Connection forgery
• Man-in-the-middle attacks

SIGTRAN Common Elements

• SIGTRAN protocol stack and architecture
• SIGTRAN terminology
• SIGTRAN layer interaction
• Peer-to-peer model
• Adaptation layer common message format
• Common header
• Common message classes
• Message types
• Parameter fields
• Example message structure
• Redundancy models
• UA state management
• ASP and AS state machine
• ASP and AS state management

MTP2 Peer-to-Peer Adaptation (M2PA)

• M2PA protocol stack
• M2PA functions
• SCTP and M2PA
• Use of SCTP associations
• MTP2 SUs and M2PA equivalent messages
• SCTP streams and SCTP notifications
• M2PA operation
• Message formats
• M2PA procedures
• Link alignment
• Data transfer
• Processor outage and recovery
• Flow control
• Changeover procedure
• M2PA implementation example

MTP2 User Adaptation (M2UA)

• Information transfer between SS7 and IP networks
• MTP3 primitives exchanged with M2UA
• Differences between M2PA and M2UA
• Protocol stack and functions
• M2UA architecture
• Application servers and server processes
• Peer-to-peer relationship
• Interfaces, links and mapping
• Deployment scenarios for ASPs and SGPs
• M2UA message format
• M2UA redundancy models
• M2UA state management
• M2UA procedures
• Processor outage
• Link congestion and link changeover
• Implementation example

MTP3 User Adaptation (M3UA)

• The SIGTRAN layer
• Information transfer between SS7 and IP networks
• M3UA services
• Application servers and server processes
• Routing keys
• Deployment scenarios for ASPs and SGPs
• M3UA IP-only operation
• Point codes and ASPs
• M3UA conceptual model and addressing schemes
• M3UA message format
• M3UA redundancy model
• M3UA state management
• Network resilience
• Routing key provisioning
• Implementation example

SCCP User Adaptation (SUA)

• SUA protocol stack
• SUA functions
• Message formats
• Routing Keys (RKs) and Routing Contexts (RCs)
• Network Appearance (NA)
• Connectionless and connection-oriented services
• Stream mapping
• Carrier grade solutions
• SUA redundancy models and loadsharing
• IPSPs
• SUA implementation example

Follow On Courses

Those involved with IP services and network operation may also benefit from a Voice over IP and IMS and SIP course, while those involved specifically with IP will benefit from the MPLS Overview, IP Engineering Overview, IP Backbone Traffic Engineering, IPv6, IP QoS and IP Security courses. Other courses that may be of interest cover technology fields such as SS7, CAMEL, ATM and SDH.