ISO/IEC 13246:1997

INTERNATIONAL lSO/lEC
STANDARD 13246
First edition
1997-12-15
Information technology -
Telecommunications and information
exchange between Systems - Broadband
Private Integrated Services Network -
Inter-exchange signalling protocol-
Signalling ATM adaptation layer
Technologies de I’informa tion - T6l6communica tions et khange
d ’informa tion en tre systemes - Reseau priv6 2 /arge bande 2 intkgra tion
de Services - Protocole de signalisation d ’kchange - Couche d ’adaptation
de signalisa tion A TM
Reference number
ISO/1 EC 13246: 1997(E)
ISOIIEC 13246: 1997(E)
Conte&
Page
Foreword
Introduction
1 Scope
2 Conformance
3 Normative References
4 Definitions
5 List of Acronyms
6 Description
6.1 Common Part - AAL Type 5
6.2 SSCOP
6.3 SSCF for Broadband Inter-PINX Signalling
7 Operational Requirements
7.1 B-QSIG SAAL Connections
7.2 Traffit Management Method for B-QSIG SAAL Connections
8 B-QSIG SAAL Specification
8.1 Basic Structure
8.2 AAL Type 5
8.3 SSCOP
8.4 SSCF for Broadband Inter-PINX Signaling
Annex A - Protocol Implementation Conformance Statement (PICS) proforma for B-QSIG SAAL
Annex B - Relationship to corresponding ITU-T Recommendations for public B-ISDN UNIS 18
Annex C - Protocol data unii and related primitive sequences for establishment and release of B-QSIG
SAAL connections
0 ISO/IEC 1997
reserved. U nless otherwise specified, no part of this publication may be reproduced or utili zed in any form or by any means,
All rights
or mechani cal, i ncluding photocopyi ng and microfilm, without permiss ion in writing from the publisher.
electronie
ISO/IEC Copyright Office l Case postale 56 l CH- 12 11 Geneve 20 l Switzerland
Printed in Switzerland
0 ISO/IEC ISO/IEC 13246: 1997(E)
Foreword
ISO (the International Organization for Standardization) and IEC (the International
Electrotechnical Commission) form the specialized System for worldwide standardization.
National bodies that are members of ISO or IEC participate in the development of
International Standards through technical committees established by the respective
organization to deal with particular fields of technical activity. ISO and IEC technical
committees collaborate in fields of mutual interest. Other international organizations,
governmental and non-governmental, in liaison with ISO and IEC, also take part in the
work.
In the field of information technology, ISO and IEC have established a joint technical
committee, ISO/IEC JTC 1. Draft International Standards adopted by the joint technical
committee are circulated to national bodies for voting. Publication as an International
Standard requires approval by at least 75 % of the national bodies casting a vote.
International Standard ISO/IEC 13246 was prepared by Joint Technical Committee
ISO/IEC JTC 1, Information technology, Subcommittee SC 6, Telecommunications and
information exchange between Systems.
Annex A forms an integral part of this International Standard. Annexes B and C are for
information only.
ISO/IEC 13246: 1997(E) 0 ISO/IEC
Introduction
This International Standard is one of a series of International Standards defining Services
and signalling protocols applicable to Broadband Private Integrated Services Networks
(B-PISNs). The series uses B-ISDN concepts as developed by ITU-T and conforms to the
framework of International Standards for Open Systems Interconnection as defined by
ISOIIEC.
This particular International Standard specifies the Signalling ATM Adaptation Layer
(SAAL) protocol for use at the Q reference Point (B-QSIG SAAL).

INTERNATIONAL STANDARD 0 ISO/IEC ISO/IEC 13246: 1997(E)
Information technology - Telecommunications and information exchange
between Systems - Broadband Private Integrated Services Network - Inter-
- Signalling ATM adaptation layer
exchange signalling protocol
1 Scope
This International Standard specifies the signalling ATM adaptation layer (SAAL) protocol used at the interface
between Broadband PINXs and between Broadband PISNs within the framework of the B-QSIG signalling
System protocol family. The B-QSIG SAAL uses the functions provided by the ATM layer, and provides the
Services required by the B-QSIG Layer 3 signalling protocols.
2 Conformance
In Order to conform to this International Standard, a PINX shall satisfy requirements identified in the Protocol
Implementation Conformance Statement (PICS) in annex A.
3 Normative References
The following Standards contain provisions which, through reference in this text, constitute provisions of this
International Standard. At the time of publication, the editions indicated were valid. All Standards are subject to
revision, and Parties to agreements based on this International Standard are encouraged to investigate the
possibility of applying the most recent editions of the Standards indicated below. Members of IEC and ISO
maintain registers of currently valid International Standards.
- Open Systems Interconnection - Conformance testing
ISO/IEC 9646- 1: 1994, Information technology
methodology and framework - Part 1: General concepts.
- Open Systems Interconnection - Conformance testing
ISO/IEC 9646-7: 1995, Information technology
methodology and framework - Part 7: Implementation Conformance Statements.
ITU-T Rec. 1.321 (1991 j, B-ISDN Protocol Reference Model and Its Application.
ITU-T Rec. I.361 (1993), B-ISDN ATM Layer Specification.
ITU-T Rec. 1.362 (1993 j, B-ISDN ATM Adaptation Layer (AAL) Functional Description.
ITU-T Rec. 1.363.5 (1996), B-ISDN ATM Adaptation Layer (AAL) Specification - Part 5: AAL Type 5.
ITU-T Rec. 1.37 1 (1996>, Traffit control and congestion control in B-ISDN.
ITU-T Rec. Q.2 100 (1994 j, B-ISDN Signalling ATM Adaptation Layer Overview Description.
ITU-T Rec. Q.2110 (1994), B-ISDN ATM Adaptation Layer - Service Specific Connection Oriented Protocol
(SSCOP).
ITU-T Rec. Q.2130 (1994), B-ISDN Signalling ATM Adaptation Luyer - Service Specific Coordination
Function for Support of Signalling at the User-to-Network Interface (SSCF at UNI).
4 Definitions
For the purposes of this International Standard, the definitions given in ITU-T Recommendations 1.363.5,
Q.2110 and Q.2130 apply.
5 List of Acronyms
AAL ATM Adaptation Layer
Asynchronous Transfer Mode
ATM
B-ISDN Broadband ISDN
B-PISN Broadband Private Integrated Service Network

0 ISO/IEC
ISO/IEC 13246: 1997(E)
B-PINX B-PISN Exchange
B-QSIG Broadband QSIG
CRC Cyclic Redundancy Check
Inter-PINX-Link
IPL
PICS Protocol Implementation Conformance Statement
Private Services Network exchange
PINX
SAAL Signalling AAL
Service Data Unit
SDU
SPC Semi-Permanent Connection
Service Specific Convergence Functions
SSCF
SSCOP Service Specific Connection Oriented Protocol
UBR Unspecified Bit Rate
UNI User Network Interface
6 Description
The SAAL protocol for Broadband Inter-PINX signalling uses the Services of the ATM layer and provides the
Services required by the B-QSIG Layer 3 signalling protocols. It is based on the generic framework outlined by
Recommendations 1.362 for the functional description of the AAL, and Q.2100 for the signalling AAL
specification.
The B-QSIG SAAL allows a B-QSIG SAAL user (i.e. a layer 3 signalling protocolj to communicate with its
peer entity. In particular, it provides for a reliable transfer of layer 3 signalling messages. The information
transfer between the B-QSIG SAAL user and the B-QSIG SAAL uses primitives and is performed in Message
Mode.
Two peer-to-peer operational procedures are specified: Unassured or Assured Operation. The support of the
Assured Operation is mandatory. The support of Unassured Operation is optional.
NOTE The use of unassured Operation is not required by the B-QSIG layer 3 signalling protocol.
The basic structure of the B-QSIG SAAL is contained in Figure 1. For the B-QSIG SAAL, 3 sublayers are
defined similar to those shown in Figure 1 of Rec. Q.2100:
- SSCF for B-QSIG
- SSCOP
- Common Part - AAL Type 5.
SSCF for B-QSIG signalling
--v-m--------
Q.2110 SSCOP
(Service Specific Connection Oriented Protocol)
-------------
1.363.5 AAL type 5
-------------
Figure 1 - B-QSIG SAAL Structure
6.1 Common Part - AAL Type 5
AAL Type 5 provides transparent transfer and CRC checking (32 Bits) for SSCOP SDUs, Segmentation into
ATM cells, and reassembly.
ISO/IEC 13246: 1997(E)
0 ISO/IEC
SSCOP
6.2
SSCOP provides the basic mechanisms for the establishment and release of connections and the reliable
exchange of information between B-PINX peer entities.
SSCF for Broadband Inter-PINX Signalling
6.3
SSCF maps the particular requirements of the Broadband Inter-PINX layer 3 signalling protocols to the
SSCOP Services.
7 Operational Requirements
B-QSIG SAAL requires that the following configuration information is available at both sides of an IPL (the
method for making this information available for both peer entities is outside the scope of this International
Standard):
-
which virtual channel acts as the signalling channels for the IPL
-
which traffit management method is applied on that virtual channel.
7.1 B-QSIG SAAL Connections
The B-QSIG SAAL operates in a connection-oriented mode. The B-QSIG SAAL connection(s) shall be
established as part of the IPL establishment, and shall reside permanently (except for error cases).
NOTE B-QSIG SAAL connections are established between two peer entities at the two ends of an IPL.
7.2 Traffit Management Method for B-QSIG SAAL Connections
For the Operation of the B-QSIG SAAL protocol, the peer entities at two ends of an IPL shall be pre-
configured with the traffit resources allocated to the B-QSIG SAAL connections. For each B-QSIG SAAL
connection (or for a set of them together), the following are examples of Parameters that tan be pre-
configured (see also ITU-T Rec. I.371):
a peak cell rate indication (only), e.g. 167 cells/sec.
a)
peak cell rate, sustainable cell rate, and maximum burst size (together)
W
an indication as “unspecified bit rate” (UBR).
c>
The method of configuring the traffit resources allocated to the B-QSIG SAAL connection is outside the
scope of this International Standard. However, it is essential for the traffit management of B-QSIG SAAL
connections that both peer entities at the IPL apply the same allocation of Parameters.
8 B-QSIG SAAL Specification
Basic Structure
8.1
Clause 5 of ITU-T Rec. Q.2100 applies.
8.2 AAL Type 5
ITU-T Rec. 1.363.5 applies.
8.3 SSCOP
ITU-T Rec. Q.2110 applies.
NOTE The SSCOP tan be combined with different Service Specific Coordination Functions (SSCFs) to offer
different AAL Services. As a result, the SSCOP specification defines mandatory functions for a general protocol.
Some of these functions are not needed within B-QSIG SAAL. Therefore, it is possible for an implementation not to
implement a certain SSCOP function and still meet the mandatory requirements of B-QSIG SAAL (e.g. the SSCOP
local data retrieval function is not needed within B-QSIG SAAL), provided that the SSCOP implementation provides
for the Services used by the B-QSIG SAAL-SSCF.
A fully compliant SSCOP implementation according to ITU-T Rec. Q.2110 meets the requirements for the SSCOP of
this International Standard.
0 ISO/IEC
ISOlIEC 13246: 1997(E)
8.4 SSCF for Broadband Inter-PINX Signalling
SAAL Services Provided by the SSCF for B-QSIG Signahing
8.4.1
The foll&ng Services shall be provided. Unless specified differently, they shall be provided as specified
in clause 5 of ITU-T Rec. Q.2130:
-
assured transfer of data.
-
transparency of transferred information.
NOTE The SSCF does not interpret the structure or meaning of SDUs; as a default, it supports the transfer of
octet-aligned SDUs up to a maximum of 4 096 octets.
-
establishment and release of B-QSIG SAAL connections for assured transfer of data.
B-QSIG SAAL connections are established during IPL establishment, and reside permanently.
However, in certain error seenarios, the SSCF may release B-QSIG SAAL connections to recover
from error situations.
The following SAAL Services may optionally be provided:
-
unacknowledged transfer of data.
The use of this Service is not specified by the B-QSIG layer 3 signalling protocol.
8.4.2 Functions of the SSCF and Signalling Protocol Stack
Clause 6 of ITU-T Rec. Q.2130 applies with the following exception:
- only Point-to-Point B-QSIG SAAL connections shall be supported. In particular, B-QSIG SAAL shall
not provide the broadcast capability described in clause 6/Q.2130.
8.4.3. Definition of the Boundary of SSCF to B-QSIG-Layer 3 Protocols
@lause 7 of ITU-T Rec. Q.2130 applies with the following exceptions:
- The support of the AAL-UNITDATA primitive is not mandatory. The use of this primitive is not
specified by B-QSIG layer 3 signalling protocol.
- The support of layer 3 peer-to-peer messages in the AAL-ESTABLISH and AAL-RELEASE
primitives is not mandatory. The use of those Parameter data in these primitives is not specified by the
B-QSIG layer 3 signalling protocol.
8.4.4 Definition of the Boundary of SSCF with SSCOP
Clause 8 of ITU-T Rec. Q.2130 applies with the following exception:
- The support of the AA-UNITDATA primitive is not mandatory.
8.4.5 State Transition Table sf SSCF for Supporting B-QSIG Signalling
Clause 9 of ITU-T Rec. Q.2130 applies with the exceptions specified in sections 8.4.3 and 8.4.4 above.
8.4.6 Boundary to Layer Management
No requirements have been identified.
8.4.7 Applicability of SSCOP Parameters and Timers to B-QSIG Signalling
The values specified in Table 4 of ITU-T Rec. Q.2130 are used as default Parameters.
However, parameter- and timer values at the B-QSIG-IPL shall be configurable, in Order to be able to
select a proper set of parameter- and timer values depending on the use, condition, IPL link rate, round-trip
delay, and receiver resequencing buffer size. As a general guide, Timer POLL should be set to as large a
-
value as possible that still maintains throughput efficiency and satisfies the average and maximum delivery
of data.
For the signalling channels at the Q reference Point, no restrictions to operating at below 10 kbit/s applies.
8.4.8
PICS Proforma for SSCOP AND SSCOP-SSCF
Annex A applies.
8.4.9 SSCF for Semi-Permanent Connection (SPC) Control Signalling
Functions for the support of semi-permanent connections are outside the scope of this International
Standard.
0 ISO/IEC ISO/IEC 13246: 1997(E)
Annex A
(normative)
Protocol Implementation Conformance Statement (PICS) proforma for B-QSIG SAAL
A.l Introduction
A.l.l Basic reference documents for PICS proforma specifications
General rules for the specification of PICS proforma are provided by ISO/IEC 9646-1. Detailed guidance for
the specification of PICS proforma is provided by ISO/IEC 9646-7; in particular the structure of a PICS
proforma, the questions to be asked, the Syntax and notation to be used and the semantics of the questions
and expected answers.
For a PICS proforma, specific acronyms and terms are used as defined in ISO/IEC 9646- 1 or ISO/IEC 9646-
7, e.g.:
Implementation Conformance Statement
- ICS
Implementation Conformance Statement proforma
- ICS proforma
A row in an ICS (proforma) table
- ICS (proforma) item
Protocol ICS
- PICS
Protocol ICS proforma
- PICS proforma
-
An allowed entry in the Status column for an item in an ICS proforma table
Status (value)
An allowed entry in the support or supported values columns for an item in an IC,T:
(support) answer
question
Copyright Information
A.l.2
Users of this specification may freely reproduce the PICS proforma of this Annex A so that it tan be used for
its intended purpose and may further publish the completed PICS.
AS.3 Structure of this PICS proforma
This PICS proforma is subdivided into (sub-)clauses as follows:
- Instructions (A.2)
- Purpose of a PICS proforma (A.2.1)
- Instructions for completing the PICS proforma (A.2.2)
- Additional Information (A.2.3)
- Exception Information (A.2.4)
- Legend for the columns of the PICS proforma tables (A.2.5)
- Legend for further indications of the PICS proforma tables (A.2.6)
- Identification of the implementation (A.3) including:
- Identification of the protocol for which this PICS applies (A.3.7)
- Global Statement of conformance (A.4)
- SSCOP (A.5)
- SSCOP-SSCF B-QSIG Protocol Capabilities (A.6)

0 ISO/IEC
ISO/IEC 13246: 1997(E)
A.2 Instructions
A.2.1 Purpose of a PICS proforma
To evaluate conformance of a particular implementation, it is necessary to have a. Statement of which
capabilities and Options have been implemented for a given OS1 specification. Such a Statement is called an
Implementation Conformance Statement (ICS).
this Statement is called “Protocol Implementation Conformance Statement”
For protocol specifications,
(PICS). For the Provision of this Statement, a fixed format questionnaire called PICS proforma has to be
used. A completed PICS proforma is the PICS for the implementation in question. It is an ICS (as defined in
ISO/IEC 9646-7) for an implementation or System which Claims to conform to a given specification.
The PICS tan have a number of uses, including:
-
by the protocol implementor, as a check list for implernentations to reduce the risk of unintended non-
conformance, e.g. through oversight;
- by the supplier and acquirer, or potential acquirer, of the implementation, as a detailed indication of the
capabilities of the implementation, stated relative to the common basis for understanding provided by the
Standard ’s PICS proforma;
- by the user or potential user of the implementation, as a basis for initially checking the possibility of
interworking with another implementation - while interworking tan never be guaranteed, failure to
interwork tan often be predicted from incompatible PICS
- by a protocol tester-, as the basis for selecting appropriate tests against which to assess the Claim for
conformance of the implementation.
The PICS proforma of this Annex therefore reflect a compromise between these different requirements.
A.2.2 Instructions for completing the PICS proforma
The supplier of a protocol implementation which is claimed to conform to this International Standard shall
complete the following Protocol Implementation Conformance Statement (PICS) proforma.
The PICS proforma is a fixed format questionnaire. The supplier of the implementation shall complete this
questionnaire, in particular identify the implementation, complete the global Statement of conformance, and
providing the answers in the rows of the tables in clauses AS - A.6. The structure of the tables is explained
in subclauses A.2.5 and A.2.6. For each row in each table, the supplier shall enter an explicit answer (i.e. by
ticking the appropriate “yes ”, “no ”, or “N/A” in each of the support column boxes provided. Where a support
column box is left blank, or where it is marked “N/A” without any tick box, no answer is required. If a
“prerequisite line” (see A.2.6 below) is used after a subclause heading or table title, and its predicate is false,
no answer is required for the whole sublause or table, respe
...