SIST-TS ETSI/TS 101 909-12 V1.1.1:2005

Digital Broadband Cable Access to the Public Telecommunications Network; IP Multimedia Time Critical Services; Part 12: Internet Signalling Transport Protocol (ISTP)

Production of IPCablecom specification for the equivalence to J.165 suitable for the EU.

Digitalni širokopasovni kabelski dostop do javnih telekomunikacijskih omrežij – Večpredstavnostne časovno kritične storitve IP – 12. del: Internetni transportni protokol signalizacije (ISTP)

General Information

• Status: Published
• Publication Date: 31-Dec-2004
• ICS: 33.040.35 - Telephone networks
• Technical Committee: SPN - Services and Protocols for Networks
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Jan-2005
• Due Date: 01-Jan-2005
• Completion Date: 01-Jan-2005
• Ref Project: ETSI TS 101 909-12 V1.1.1 (2002-11) - Digital Broadband Cable Access to the Public Telecommunications Network; IP Multimedia Time Critical Services; Part 12: Internet Signalling Transport Protocol (ISTP)

Standards Content (Sample)

SLOVENSKI STANDARD
01-januar-2005
'LJLWDOQLãLURNRSDVRYQLNDEHOVNLGRVWRSGRMDYQLKWHOHNRPXQLNDFLMVNLKRPUHåLM±
9HþSUHGVWDYQRVWQHþDVRYQRNULWLþQHVWRULWYH,3±GHO,QWHUQHWQLWUDQVSRUWQL
SURWRNROVLJQDOL]DFLMH,673
Digital Broadband Cable Access to the Public Telecommunications Network; IP
Multimedia Time Critical Services; Part 12: Internet Signalling Transport Protocol (ISTP)
Ta slovenski standard je istoveten z: TS 101 909-12 Version 1.1.1
ICS:
33.040.35 Telefonska omrežja Telephone networks
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

Technical Specification
Digital Broadband Cable Access to the
Public Telecommunications Network;
IP Multimedia Time Critical Services;
Part 12: Internet Signalling Transport Protocol (ISTP)

2 ETSI TS 101 909-12 V1.1.1 (2002-11)

Reference
DTS/SPAN-130290
Keywords
IP, protocol, transport
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ETSI
3 ETSI TS 101 909-12 V1.1.1 (2002-11)
Contents
Intellectual Property Rights.6
Foreword.6
Introduction .6
1 Scope.7
2 References.7
3 Definitions, abbreviations and conventions .7
3.1 Definitions.7
3.2 Abbreviations.8
3.3 Convention.9
4 Signalling Protocols.9
5 Void.9
6 Overview and background motivation .9
6.1 Service goals.9
6.2 IPCablecom reference architecture.10
6.3 Introduction to ISTP.11
6.4 Specification goals.13
6.5 Specification interfaces.13
7 Architecture.13
7.1 IPCablecom to PSTN .13
7.2 Signalling architecture network model.14
7.3 Distribution Model.16
7.4 Guaranteed performance.17
7.5 Protocol stack.18
8 Functional areas.18
8.1 Mapping relationships.18
8.1.1 SS7 numbering.19
8.1.2 IPCablecom numbering.19
8.1.3 ISTP numbering.20
8.2 Message distribution.20
8.3 Dynamic Mapping.20
8.4 Relationships.21
8.5 Initialization.21
8.6 Recovery.22
8.7 Dynamic provisioning.23
8.8 Administration.23
8.9 Security.23
8.10 Maintenance.23
8.11 Measurement.23
8.12 Alarms.24
8.13 Congestion.24
8.14 Management of lower layers .24
9 Protocol.24
9.1 General requirements.24
9.1.1 Communication with the lower layers .24
9.1.2 Encoding rules.25
9.1.3 SS7 Load-sharing and sequencing .25
9.2 Procedures.25
9.2.1 Registration of circuit identifiers .25
9.2.1.1 Circuit registration.26
9.2.1.2 Circuit deregistration.26
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4 ETSI TS 101 909-12 V1.1.1 (2002-11)
9.2.2 Activation of registered circuits.27
9.2.2.1 Circuit activation.27
9.2.2.2 Forced exclusive circuit activation.27
9.2.2.3 New work circuit activation .28
9.2.2.4 Circuit deactivation.28
9.2.3 Registration of subsystem transactions .28
9.2.3.1 Subsystem registration.29
9.2.3.2 Subsystem transaction deregistration .29
9.2.4 Activation of registered subsystem transactions .29
9.2.4.1 Subsystem activation.30
9.2.4.2 Forced exclusive subsystem activation .30
9.2.4.3 Subsystem deactivation.30
9.2.5 Message transfer.31
9.2.5.1 ISUP message transfer .31
9.2.5.2 TCAP message transfer.31
9.3 Failure detection and handling .31
9.3.1 Heartbeat.32
9.3.2 Signalling gateway procedures .32
9.3.2.1 Signalling point accessibility .32
9.3.2.2 Subsystem accessibility.32
9.3.2.3 SS7 network accessibility .32
9.3.2.4 MGC/CMS accessibility.33
9.3.2.5 Congestion on the SS7 network .33
9.3.2.6 Congestion on the IP network .33
9.3.3 MGC and CMS procedures.33
9.3.3.1 Signalling point accessibility .33
9.3.3.2 SS7 Network accessibility.33
9.3.3.3 Signalling gateway accessibility .33
9.3.3.4 SS7 Network congestion.34
9.3.3.5 Congestion on the IP network .34
9.4 Message format.34
9.4.1 Message types.35
9.4.2 Message nature.35
9.4.3 Parameters.36
9.4.3.1 asciiString.36
9.4.3.2 cic.36
9.4.3.3 CircuitRange.36
9.4.3.4 DestinationType.37
9.4.3.5 InaccesibilityReason.37
9.4.3.6 Integer.37
9.4.3.7 isupClientReturnValue.37
9.4.3.8 isupTransferFormat.37
9.4.3.9 NormalizedISUPMsg.38
9.4.3.10 NormalizedTCAPMsg.38
9.4.3.11 pointCode.38
9.4.3.12 QualityOfService.38
9.4.3.13 rawISUPMsg.38
9.4.3.14 rawTCAPMsg.38
9.4.3.15 routingLabel.38
9.4.3.16 sccpPartyAddress.39
9.4.3.17 stream.39
9.4.3.18 subsystem.39
9.4.3.19 subsystemActionReturnValue.39
9.4.3.20 tcapTransferFormat.40
9.5 Messages.40
9.5.1 Circuit registration and activation messages.40
9.5.1.1 Circuit registration.40
9.5.1.2 Circuit deregistration.40
9.5.1.3 Circuit activation.41
9.5.1.4 Forced exclusive circuit activation.41
9.5.1.5 New work circuit activation .41
9.5.1.6 Circuit deactivation.41
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5 ETSI TS 101 909-12 V1.1.1 (2002-11)
9.5.1.7 Forced circuit deactivation.41
9.5.1.8 New work circuit deactivation .41
9.5.2 Subsystem transaction registration and activation messages .42
9.5.2.1 Subsystem registration.42
9.5.2.2 Subsystem deregistration.42
9.5.2.3 Subsystem activation.42
9.5.2.4 Exclusive subsystem activation.43
9.5.2.5 Subsystem deactivation.43
9.5.2.6 Forced subsystem deactivation.43
9.5.3 Message transfer.43
9.5.3.1 ISUP-Message-Transfer.43
9.5.3.2 TCAP-Message-Transfer.43
9.5.4 Flow control.44
9.5.4.1 Heartbeat.44
9.5.4.2 Signalling point inaccessible.44
9.5.4.3 Signalling point accessible.45
9.5.4.4 Subsystem inaccessible.45
9.5.4.5 Subsystem accessible.45
9.5.4.6 Signalling point congestion.45
9.5.4.7 Local Congestion.46
9.5.4.8 SS7 Network accessible .46
9.5.4.9 SS7 Network inaccessible .46
Annex A (informative): SCTP and TCP usage Recommendations.47
A.1 SCTP Usage recommendations.47
A.1.1 SCTP Stream Mapping.47
A.1.2 SCTP Congestion Information .47
A.2 TCP usage recommendations .47
A.2.1 Delaying of packets .48
A.2.2 Non-blocking interface.48
A.2.3 Disable TCP socket linger.48
Annex B (informative): ISTP message flows and timer definitions.49
B.1 Timers.49
B.2 MGC requests ISUP service procedure.50
B.3 MGC terminates ISUP service procedure .51
B.4 Residential CA requests TCAP service procedure.52
B.5 Residential CA terminates TCAP service procedure .53
B.6 MGC failover procedure .54
B.7 MGC switchover procedure .55
Annex C (informative): Bibliography.56
History .57

ETSI
6 ETSI TS 101 909-12 V1.1.1 (2002-11)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (http://webapp.etsi.org/IPR/home.asp).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This Technical Specification (TS) has been produced by ETSI Technical Committee Services and Protocols for
Advanced Networks (SPAN).
The present document is part 2 of a multi-part deliverable. Full details of the entire series can be found in part 1 [3].
Introduction
This version is based on the 8TD112r2 from SPAN #78 in June 02 and the direct continuation of D8-36 presented at
TC-AT-D in July 02. The main changes are due to the new mechnism for OTID assignment and the additions in the
Subsystem registration. Proposed text changes from Ray Forbes are also covered.
ETSI
7 ETSI TS 101 909-12 V1.1.1 (2002-11)
1 Scope
The present document describes the Internet Signalling Transport Protocol (ISTP) to implement Signalling System
No. 7 signalling interconnection to a distributed IPCablecom architecture.
The present document addresses the protocol to implement ETSI SS7 used for signalling interconnection in a
distributed IPCablecom architecture. Specifically, it defines the messages and procedures for transporting SS7 ISUP,
and TCAP messages as defined by ETSI specifications between the IPCablecom control functions (Media Gateway
Controller and Call Management Server) and the SS7 Signalling Gateway. The IPCablecom Networks are always
connected to the PSTN/ISDN using standard ETSI SS7 interfaces Ref (ISUP, MTP and SCCP)
Areas beyond the scope of the present document include:
• address layer management (SNMP), security, and measurements; these are covered in other IPCablecom
Recommendations;
• implementation and vendor dependant issues, such as performance, functional distribution, network
configuration, etc.;
• details about CMS, MGC, and other media communication applications.
2 References
The following documents contain provisions which, through reference in this text, constitute provisions of the present
document.
• References are either specific (identified by date of publication and/or edition number or version number) or
non-specific.
• For a specific reference, subsequent revisions do not apply.
• For a non-specific reference, the latest version applies.
[1] ETSI EN 300 356: "Integrated Services Digital Network (ISDN); Signalling System No.7 (SS7);
ISDN User Part (ISUP) version 4 for the international interface".
[2] ETSI ETS 300 287-1 (Edition 2): "Integrated Services Digital Network (ISDN); Signalling System
No.7; Transaction Capabilities (TC) version 2; Part 1: Protocol specification [ITU-T
Recommendations Q.771 to Q.775 (1993), modified]".
[3] ETSI TS 101 909-1: "Digital Broadband Cable Access to the Public Telecommunications
Network; IP Multimedia Time Critical Services; Part 1: General ".
3 Definitions, abbreviations and conventions
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
Access Node (AN): As used in the present document, an Access Node is a layer two termination device that terminates
the network end of the J.112 connection. It is technology specific. In ITU-T Recommendation J.112 annex A it is called
the INA while in Annex B it is the CMTS.
Cable Modem (CM): layer two termination device that terminates the customer end of the J.112 connection
ETSI
8 ETSI TS 101 909-12 V1.1.1 (2002-11)
Gateway: devices bridging between the IPCablecom IP Voice Communication world and the PSTN
NOTE: Examples are the Media Gateway which provides the bearer circuit interfaces to the PSTN and transcodes
the media stream, and the Signalling Gateway which sends and receives circuit switched network
signalling to the edge of the IPCablecom network.
IPCablecom: ETSI project that includes an architecture and a series of Recommendations that enable the delivery of
real time services over the cable television networks using cable modems
Signalling Gateway (SG): signalling agent that receives/sends SCN native signalling at the edge of the IP network
NOTE: In particular the SS7 SG function translates variants ISUP and TCAP in an SS7-Internet Gateway to a
common version of ISUP and TCAP.
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
AN Access Node
ANS Announcement Server
ATM Asynchronous Transfer Mode
CA Call Agent
CIC Circuit Identification Code
CID Circuit ID
CM Cable Modem
CMS Call Management Server
DNS Directory Name Server
DPC Destination Point Code
HFC Hybrid Fibre/Coaxial [cable]
IP Internet Protocol
ISTP Internet Signalling Transport Protocol
ISUP ISDN User Part
LAN Local Area Network
MAC Media Access Control
MG Media Gateway
MGC Media Gateway Controller
MTA Media Terminal Adapter
MTP Message Transfer Part
NI Network Identifier
OPC Origination Point Code
OTID Origination Transaction Identity
PHY Physical Layer
PSTN Public Switched Telephone Network
QoS Quality of Service
RTP Real Time Protocol
SCCP Signalling Connection Control Part
SCP Service Control Point
SCTP Stream Control Transmission Protocol
SG Signalling Gateway
SIP Session Initiation Protocol
SLS Signalling Link Selection
SS7 Signalling System No. 7
SSN Switching Signalling Node
SSP Signal Switching Point
TCAP Transaction Capabilities Application Part
TCP Transmission Control Protocol
UDP User Datagram Protocol
WAN Wide Area Network
ETSI
9 ETSI TS 101 909-12 V1.1.1 (2002-11)
3.3 Convention
If the present document is implemented, the key words "MUST" and "SHALL" are to be interpreted as indicating a
mandatory aspect of the present document.
4 Signalling Protocols
The signalling protocols used for interconnection in a distributed IPCablecom PSTN gateway architecture shall be
designed to support ETSI Signalling System No. 7 (SS7).
5 Void
6 Overview and background motivation
6.1 Service goals
Cable operators are interested in deploying high-speed data and multimedia communications services on cable
television systems. It is necessary to have a series of interface Recommendations that will permit the early definition,
design, development, and deployment of packetized data-based services over cable systems on a uniform, consistent,
open, non-proprietary, multi-vendor interoperable basis. The intended system enables Internet Protocol (IP) based voice
communications, video, and data services to be provided to the customer over an all-coaxial or hybrid-fibre/coax (HFC)
cable access network by utilizing ITU-T Recommendation J.112 as the basic foundation for data transport. This is
shown in simplified form in figure 1.
Wide-Area Access Node
Network AN
AN Cable Cable CM Customer Premises
Network Side Network Modem Equipment Interface
Interface (CM)
Customer Premises
Equipment
T0912270-01
Transparent IP traffic through the system
(118825
Figure 1: Transparent IP traffic through the data-over-cable system
The transmission path over the cable system is realized at the headend by an Access Node and at each customer location
by a CM. The intent is for operators to transfer IP traffic transparently between these interfaces, thereby providing the
basic transport mechanism for data-based multimedia services.
When providing voice and other multimedia services over the J.112 access network; many issues need to be addressed
for incoming and outgoing communications. These issues include but are not limited to:
• voice or other media content conversion;
• call control signalling;
• quality of service control;
• call control signalling interoperability with the existing public network;
ETSI
10 ETSI TS 101 909-12 V1.1.1 (2002-11)
• media interfaces to the existing public network;
• data transactions to public databases;
• routing mechanisms;
• billing;
• operations and maintenance;
• security;
• privacy.
The IPCablecom project is addressing these issues through the development and publication of reference architecture
and a series of corresponding interface specifications. The present document, the IPCablecom Internet Signalling
Transport Protocol (ISTP) addresses the issue of call control signalling interoperability with the existing public
network.
6.2 IPCablecom reference architecture
The conceptual diagram in figure 2 portrays a high level architectural view of the IPCablecom network.
Subscriber equipment consists of a Media Terminal Adapter (MTA), the primary purpose is to provide a gateway
between the subscriber-side voice/video media devices and the rest of the IPCablecom network. Two types of MTAs
exist. The first is a standalone MTA that connects via a local area network (LAN) interface (e.g. IEEE 802.3) to a CM.
The second is an embedded MTA, which integrates the standalone MTA functions with the CM media access control
(MAC) and physical layer (PHY) functions in the same physical package.
Physical connectivity to the backbone consists of an all-coax or a hybrid fibre-coax (HFC) J.112 enabled cable access
network with J.112 Quality of Service (QoS). The J.112 HFC access network terminates at the head end Access Node.
The Access Node provides either a bridging point or a routing point to the backbone managed IP network.
The Call Management Server (CMS) provides control, routing, and signalling services in connection with voice
communications provided via IPCablecom. It is responsible for authorization and plays a roll in feature implementation.
The media servers provide support services for media streams such as conference mixing bridges and announcement
servers.
CMS is a meta-term for a collection of functions (both specified and unspecified within IPCablecom) within a server or
cluster of servers that work together to perform "line-side" control functions within an IPCablecom network. The
simplest way to think of a CMS is to imagine the functions of a local switch call controller being extrapolated and
placed into a server farm. The CMS includes a minimum of a call agent and a gate controller. It may have feature and
routing logic. It may or may not contain a media gateway controller, meaning that it can implement some transit switch
functionality as well as local. A SIP-proxy may also be contained within a CMS, although IPCablecom does not include
SIP in the architecture.
A Call Agent is a specific control function contained within the CMS. It implements the server side of the protocol
interface and controls MTAs. The MGC is a specific control function that may be contained within a CMS or may be
standalone in the network. It implements the server side of the TGCP protocol interface and is used to control PSTN
media trunking gateways.
The Public Switched Telephone Network (PSTN) gateway provides access from the subscriber network into the PSTN
network. For outgoing communications, the Media Gateway (MG) converts the voice samples arriving in RTP packets
into the appropriate TDM format and delivers the resulting voice stream to the public network. The Media Gateway
Controller (MGC) provides signalling information related to the communication to the PSTN through the services of the
Signalling Gateway (SG). This signalling information exchanged with the PSTN is used by the components of the
IPCablecom network to manage the communication's progress and provide required features and functionality. In
addition, IPCablecom gateways also interwork with the public databases of the PSTN using SS7 TCAP queries,
allowing the IPCablecom network to query for publicly available data (freephone numbers, local number portability
service, credit card data, etc.).
ETSI
11 ETSI TS 101 909-12 V1.1.1 (2002-11)
For incoming communications, IPCablecom equipment will convert arriving TDM circuit voice to RTP packets
carrying appropriately coded samples. It will also take the incoming communication related SS7 ISUP signalling and
convert it to signalling understood by IPCablecom devices.
The OSS back office provides support services such as billing, provisioning, fault determination, problem resolution,
and other support services.
Note that ISTP makes no assumptions on how the CMS and MGC and other ISTP-User functions are distributed or
physically located: they all MAY be collocated, each distributed on separate computers, or all distributed as separate
nodes and processes across a wide network and a large number of computers. ISTP was designed to handle all these
cases.
Embedded
Call Management
Server
Cable
MTA
Modem
HFC
CMTS
network
Announcement Servers
Media
(DOCSIS) Conference Mixing Bridges
Standalone
Servers
...
MTA
Cable
MTA
Media
Modem
Gateway
Managed IP Backbone
PSTN
Media Gateway
(QoS Features)
Controller
(Headend, Local, Regional)
Embedded
Signaling
Cable
MTA
Gateway
Modem
HFC
CMTS
network
(DOCSIS)
Standalone
Billing
OSS
MTA
Provisioning
Backoffice
Problem Resolution
Cable
DHCP Servers
MTA
Modem
TFTP Servers
...
Figure 2: IPCablecom reference architecture
6.3 Introduction to ISTP
ISTP contains features for initialization; address mapping from the SS7 domain to the IP domain; message delivery for
SS7 Integrated Services Digital Networks (ISDN) User Part (ISUP), Transaction Capabilities Application Part (TCAP);
congestion management; fault management; maintenance operations; and redundant configuration support. ISTP
bridges the gap between basic IP transport mechanisms and application level signalling. Although not a translation of
the SS7 Message Transport Protocol 3 (MTP3) and Signalling Connection and Control Protocol (SCCP) protocols,
ISTP implements analogues to some of the MTP3 and SCCP functions in a fashion appropriate to distributed systems
communicating over an IP network.
Thus ISTP distributes transparently the ISUP and TCAP functions into multiple elements while retaining the
computational intensive SCCP/MTP2/MTP3 SS7 stack elements in the Signalling Gateway (see figure 3). This also
keeps the SCCP Global Title tables in a secure central location, as preferred by SS7 network operators. This breakdown
also allows ISTP-User applications to have access to all the TCAP and ISUP data, which may be necessary for some
advanced features. It provides the maximum isolation from SS7 details while providing full transaction and signalling
information. It also allows new ISTP-User applications that require other SS7 application part protocols, such as GSM
MAP and IS41 MAP, to be added in a graceful and backward compatible manner by installing the MAP agents over
ISTP as needed.
ETSI
12 ETSI TS 101 909-12 V1.1.1 (2002-11)
ISTP-USER at the SG ISTP-USER at an I PCablecom Node
(Nodal Interworking Function)
SCCP
ISUP
TCAP application
subsystems
CID based
SSN based
distribution
ISUP
TCAP
distribution
ISTP
ISTP
SCCP
e.g. SCTP
MTP L3
e.g. SCTP
MTP L2 IP
IP
MTP L1
physical layer
physical layer
SS7 network IP based network
Figure 3: Protocol stack in IPCablecom elements
The ISTP is designed to support a wide variety of configurations, ranging from a non-redundant SS7 Signalling
Gateway serving a single non-redundant Media Gateway Controller to a distributed, fully redundant SS7 Signalling
Gateway serving multiple distributed and redundant Media Gateway Controllers and Call Management Servers, and
potentially other network elements.
NOTE: The term ISTP-User will be a generic term for any element, node, or process that uses the ISTP stack for
signalling communications. For the first phase of IPCablecom this includes the CMS, MGC and SG. In
the future, other types of elements may include the stack.
The ISTP contains functions for:
• Initialization.
• Registration Of Circuit IDs With The SS7 Gateway.
• Address Mapping Between The SS7 and IP domains.
• ISUP Maps Based On Point Code and Circuit Identification Code.
• TCAP Maps Based On Point Code and Origination Transaction ID (OTID) from the SS7 side of the SG to the
transaction ID used on the IPCablecom side and vice versa.
• ISUP/TCAP Message Delivery Using Reliable Transport.
...