ETSI ETS 300 478-1 ed.1 (1998-02)

Network Aspects (NA); Connectionless Broadband Data Service (CBDS) over Asynchronous Transfer Mode (ATM); Framework and protocol specification at the User-Network Interface (UNI); Part 1: Specification

DE/NA-053205

Omrežni vidiki (NA) –Nepovezavna širokopasovna podatkovna storitev (CBDS) z asinhronim prenosnim načinom (ATM) – Okvir in specifikacija protokola vmesnika uporabnik-omrežje (UNI) – 1. del: Specifikacija

General Information

• Status: Published
• Publication Date: 22-Feb-1998
• Technical Committee: NA 5 - Broadband Networks
• Current Stage: 12 - Completion
• Due Date: 27-Feb-1998
• Completion Date: 23-Feb-1998
• Ref Project: SIST ETS 300 478-1 E1:2003 - Network Aspects (NA); Connectionless Broadband Data Service (CBDS) over Asynchronous Transfer Mode (ATM); Framework and protocol specification at the User-Network Interface (UNI); Part 1: Specification

Standards Content (Sample)

SLOVENSKI STANDARD
SIST ETS 300 478-1 E1:2003
01-december-2003
2PUHåQLYLGLNL1$±1HSRYH]DYQDãLURNRSDVRYQDSRGDWNRYQDVWRULWHY&%'6]
DVLQKURQLPSUHQRVQLPQDþLQRP$70±2NYLULQVSHFLILNDFLMDSURWRNRODYPHVQLND
XSRUDEQLNRPUHåMH81,±GHO6SHFLILNDFLMD
Network Aspects (NA); Connectionless Broadband Data Service (CBDS) over
Asynchronous Transfer Mode (ATM); Framework and protocol specification at the User-
Network Interface (UNI); Part 1: Specification
Ta slovenski standard je istoveten z: ETS 300 478-1 Edition 1
ICS:
33.040.40 Podatkovna komunikacijska Data communication
omrežja networks
SIST ETS 300 478-1 E1:2003 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST ETS 300 478-1 E1:2003

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SIST ETS 300 478-1 E1:2003
EUROPEAN ETS 300 478-1
TELECOMMUNICATION February 1998
STANDARD
Source: NA Reference: DE/NA-053205
ICS: 33.020
Key words: Access, ATM, Broadband, CBDS, CL, Network, UNI
Network Aspects (NA);
Connectionless Broadband Data Service (CBDS)
over Asynchronous Transfer Mode (ATM);
Framework and protocol specification at the
User-Network Interface (UNI);
Part 1: Specification
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
Postal address: F-06921 Sophia Antipolis CEDEX - FRANCE
Office address: 650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
X.400: c=fr, a=atlas, p=etsi, s=secretariat - Internet: [e-mail]
Tel.: [phone] - Fax: [phone]
Copyright Notification: No part may be reproduced except as authorized by written permission. The copyright and the
foregoing restriction extend to reproduction in all media.
© European Telecommunications Standards Institute 1998. All rights reserved.

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ETS 300 478-1: February 1998
Whilst every care has been taken in the preparation and publication of this document, errors in content,
typographical or otherwise, may occur. If you have comments concerning its accuracy, please write to
"ETSI Editing and Committee Support Dept." at the address shown on the title page.

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Contents
Foreword .5
1 Scope .7
2 Normative references.7
3 Abbreviations.8
4 Framework for the provision of CBDS.9
4.1 Group addressing .9
4.2 Functional architecture.10
4.3 Connectionless server functional description .11
4.4 Interfaces .13
4.4.1 CLAI .13
4.4.1.1 Access Termination Functions (ATF).15
4.4.1.1.1 ATM Access Termination Functions (AATF).15
4.4.1.1.2 CL Access Termination Functions (CLATF).15
4.4.2 Connectionless Network Interface (CLNI).16
4.4.2.1 Network Termination Functions (NTF) .17
4.4.2.1.1 ATM Network Termination Functions (ANTF) .18
4.4.2.1.2 CL Network Termination Functions (CLNTF).18
4.5 Connections.18
4.6 Protocols.19
4.7 Numbering and addressing.19
4.7.1 Individual Address (IA) .19
4.7.2 Group Address (GA).19
4.7.3 Nested Group Address (NGA) .19
4.8 Traffic aspects: access class enforcement.20
4.8.1 Maximum Information Rate (MIR).20
4.8.2 Sustained Information Rate (SIR) and PDUs Per Time Unit (PPTU).21
4.9 Operations and maintenance.21
4.9.1 Identification of OAM information flow.21
4.9.2 OAM supported functions.21
5 Layer service and functions provided by the connectionless layer.21
5.1 Layer service provided by the connectionless layer.22
5.1.1 Description of primitives .22
5.1.1.1 CLL-UNITDATA.request.22
5.1.1.2 CLL-UNITDATA.indication.22
5.1.1.3 MCL-UNITDATA.request.22
5.1.1.4 MCL-UNITDATA.indication.23
5.1.2 Definition of parameters .23
5.1.2.1 source_address .23
5.1.2.2 destination_address.23
5.1.2.3 QoS.23
5.1.2.4 Data .23
5.2 Connectionless layer functions for user data transport.23
5.3 Transit operator selection .23
6 Protocol for the support of the CBDS on B-ISDN at the UNI .24
6.1 Protocol stack .24
6.2 Layer service expected from the AAL.24
6.3 CLNAP protocol data unit structure and encoding.25
6.3.1 Destination-Address.25
6.3.2 Source-Address.25
6.3.3 Higher-Layer-Protocol-Identifier (HLPI).26
6.3.4 PAD-length .26

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6.3.5 QoS. 26
6.3.6 CRC Indication Bit (CIB) . 26
6.3.7 Header Extension Length (HEL). 26
6.3.8 Reserved . 26
6.3.9 Header extension. 26
6.3.10 User-information . 27
6.3.11 PAD . 27
6.3.12 CRC . 27
6.4 Procedures. 27
6.4.1 Interaction between CLNAP entity and CLLR&R entity . 27
6.4.2 Primitives between CLNAP & CLLR&R entities. 27
Annex A (normative): Encodings of the destination address field and source address field. 29
Annex B (informative): CRC32 generation and checking. 30
Annex C (informative): Interworking conditions with Switched Multi-megabit Data Service (SMDS) . 31
C.1 Destination and source addresses . 31
C.2 Header Extension Length (HEL). 31
C.3 Header Extension (HE) field . 31
C.4 HLPI. 31
Annex D (informative): Additional requirements in case of address screening supplementary service . 32
Annex E (informative): Procedures. 33
E.1 Receiving procedures. 33
E.1.1 PDU checks . 33
E.1.2 Ingress error conditions. 33
E.2 Sending procedures. 34
E.2.1 PDU checks . 34
E.2.2 Egress error conditions . 34
Annex F (informative): Bibliography . 35
History. 36

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ETS 300 478-1: February 1998
Foreword
This European Telecommunication Standard (ETS) has been produced by the Network Aspects (NA)
Technical Committee of the European Telecommunications Standards Institute (ETSI).
The present document is part 1 of a multi-part ETS covering the framework and protocol specification at
the User-Network Interface (UNI) for the Connectionless Broadband Data Service (CBDS) over
Asynchronous Transfer Mode (ATM), as identified below:
Part 1: "Specification";
Part 2: "Connectionless Network Access Protocol (CLNAP); Protocol Implementation Conformance
Statement (PICS) proforma specification".
Transposition dates
Date of adoption of this ETS: 6 February 1998
Date of latest announcement of this ETS (doa): 31 May 1998
Date of latest publication of new National Standard
or endorsement of this ETS (dop/e): 30 November 1998
Date of withdrawal of any conflicting National Standard (dow): 30 November 1998

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1 Scope
This first part of ETS 300 478 describes the support of connectionless data service on Broadband
Integrated Services Digital Network (B-ISDN) in accordance with:
- ETS 300 217 [2], which details the stage 1 aspects for the Connectionless Broadband Data Service
(CBDS);
- ITU-T Recommendation I.113 [5], which defines connectionless service (vocabulary);
- CCITT Recommendation F.812 [4], which provides a service description of a CBDS. CCITT
Recommendation F.812 [4] generally describes the service to include:
- source address validation;
- addresses based on CCITT Recommendation E.164 [3] numbering;
- point-to-point and multicast information transfer;
- address screening for point-to-point and multicast information transfer;
- network capabilities for charging;
- interworking with other ConnectionLess and Connection oriented data services;
- Quality of Service (QoS) parameters.
- ITU-T Recommendation I.211 [6], which describes connectionless data service aspects. ITU-T
Recommendation I.211 [6] identifies two configurations, type (i) and type (ii) to support
connectionless data service. In type (i), a Connectionless Service Function (CLSF) is installed
outside the B-ISDN. In type (ii), a CLSF, which handles routeing of data to be transferred based on
connectionless techniques, is installed within the B-ISDN;
- ITU-T Recommendation I.327 [8], which describes "high layer capabilities" for the support of
services (e.g. connectionless service) and gives functional architectural models for the cases
mentioned in F.812 Recommendation [4];
- ITU-T Recommendation I.362 [9], which specifies the use of ATM Adaptation Layer (AAL) type 3/4
for connectionless data services (although I.362 recognizes that the use of other AAL types is for
further study) and identifies that routeing and addressing are provided by the layer located above
AAL type 3/4;
- ETS 300 349 [10], which specifies AAL type 3/4;
- ITU-T Recommendation I.364 [1], which specifies the support of Broadband Connectionless Data
Bearer Service (BCDBS) on B-ISDN.
This ETS relates to type (ii) (direct) provision of connectionless service, using B-ISDN connectionless
service. However, aspects of this ETS may be applied to some type (i) provision of connectionless
service. This ETS describes the framework for network support of CBDS and the protocol used to support
CBDS at the User Network Interface (UNI). The protocol used to support CBDS at the Network Node
Interface (NNI) is described in 300 479-1 [14].
2 Normative references
This ETS incorporates by dated and undated reference, provisions from other publications. These
normative references are cited at the appropriate places in the text and the publications are listed
hereafter. For dated references, subsequent amendments to or revisions of any of these publications
apply to this ETS only when incorporated in it by amendment or revision. For undated references the latest
edition of the publication referred to applies.
[1] ITU-T Recommendation I.364 (1993): "Support of broadband connectionless
data service on B-ISDN".

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[2] ETS 300 217-2 (1992): "Network Aspects (NA); Connectionless Broadband Data
Service (CBDS) Part 2: Basic bearer service definition".
[3] CCITT Recommendation E.164 (1991): "Numbering plan for the ISDN era".
[4] CCITT Recommendation F.812 (1992): "Broadband connectionless data bearer
service".
[5] ITU-T Recommendation I.113 (1988): "Vocabulary of terms for broadband
aspects of ISDN".
[6] ITU-T Recommendation I.211 (1993): "B-ISDN Service Aspects".
[7] ITU-T Recommendation I.324 (1988): "ISDN network architecture".
[8] ITU-T Recommendation I.327 (1993): "B-ISDN Functional Architecture".
[9] ITU-T Recommendation I.362 (1993): "B-ISDN ATM Adaptation Layer (AAL)
Functional Description".
[10] ETS 300 349: "Broadband Integrated Services Digital Network (B-ISDN);
Asynchronous Transfer Mode (ATM) Adaptation Layer (AAL) specification -
type 3/4".
[11] ISO/IEC IS 8802-6: "Information processing systems - Local Area Networks
(LAN) - Part 6: Distributed Queue Dual Bus (DQDB) Subnetwork of a
Metropolitan Area Network (MAN)".
[12] ITU-T Recommendation I.371: "Traffic Control and Congestion Control in
B-ISDN".
[13] ISO/IEC IS 10039: "LAN MAC service definition".
[14] ETS 300 479-1: "Network Aspects (NA); Connectionless Broadband Data
Service (CBDS) over Asynchronous Transfer Mode (ATM); Protocol
specification at the Network Node Interface (NNI); Part 1: Specification".
3 Abbreviations
For the purposes of this ETS, the following abbreviations apply:
AAL ATM Adaptation Layer
AATF ATM Access Termination Functions
ANTF ATM Network Termination Functions
ATF Access Termination Functions
ATM Asynchronous Transfer Mode
BAsize Buffer Allocation Size
BCD Binary Coded Decimal
BCDBS Broadband Connectionless Data Bearer Service
B-ISDN Broadband Integrated Services Digital Network
BOM Beginning Of Message
CBDS Connectionless Broadband Data Service
CF Connection Functions
CIB CRC Indication Bit
CL Connectionless
CLAI Connectionless Access Interface
CLATF CL Access Termination Functions
CLHF Connectionless service Handling Functions
CLL Connectionless Layer
CLLR&R Connectionless Layer Routeing & Relaying
CLMF Connectionless Mapping Functions
CLNAP Connectionless Network Access Protocol

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CLNI Connectionless Network Interface
CLNIP Connectionless Network Interface Protocol
CLNTF CL Network Termination Functions
CLS Connectionless Server
CLSF Connectionless Service Function
CPCS Common Part Convergence Sublayer
CPE Customer Premises Equipment
CRC Cyclic Redundancy Check
CTF Control Functions
DA Destination Address
DQDB Distributed Queue Dual Bus
EI Encapsulating Indicator
EOM End Of Message
GA Group Address
GAHF Group Address Handling Functions
GAP Group Addressed PDU
HE Header Extension
HEL Header Extension Length
IA Individual Address
IEC International Electrotechnical Commission
IM Initial MAC
IS International Standard
ISDN Integrated Services Digital Network
ISO International Organization for Standardization
LAN Local Area Network
MAC Media Access Control
MAN Metropolitan Area Network
MCL Connectionless Layer Management
MID Multiplexing Identification
MIR Maximum Information Rate
NA Network Aspects
NGA Nested Group Address
NNI Network Node Interface
NPC Network Parameter Control
NTF Network Termination Functions
OAM Operation And Maintenance
PCF Protocol Conversion Functions
PDU Protocol Data Unit
PPTU PDUs per Time Unit
QoS Quality of Service
SA Source Address
SAP Service Access Point
SAR Segmentation And Reassembly
SDU Service Data Unit
SIR Sustained Information Rate
SMDS Switched Multi-megabit Data Service
SSCS Service Specific Convergence Sublayer
SSM Single Segment Message
UNI User Network Interface
UPC Usage Parameter Control
VCI Virtual Channel Identifier
VPI Virtual Path Identifier
4 Framework for the provision of CBDS
This definition of CBDS is provided by ETS 300 217 [2] in conjunction with this ETS.
4.1 Group addressing
Group addressing is a mechanism used for multicast communication (CCITT Recommendation F.812 [4],
paragraph 2).

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Multicast information transfer allows a subscriber to send an Connectionless Network Access Protocol-
Protocol Data Unit (CLNAP-PDU) to the network which delivers the same CLNAP-PDU to several
intended recipients. The network shall deliver one and only one copy of the Group Addressed CLNAP-
PDU (GAP) across each of the Connectionless Access Interface (CLAI) associated with the individual
addresses represented by the group address (i.e. each CLAI associated with multiple destination
addresses will receive a single copy from the network). The GAP shall not be copied back to the
originating CLAI. Any recipient of a GAP may make use of the destination Group Address carried by that
GAP to multicast to the other recipients of the GAP. Non members of a group identified by a group
address (GA) may send GAPs to that group.
As a result of address screening, it is possible that some of the copies of the GAP will not be delivered, all
other copies are delivered according to the QoS.
The service provider is responsible for assigning group addresses and ensuring that each GA identifies
uniquely only one set of individual addresses. GA can be distinguished from individual addresses by the
address type.
4.2 Functional architecture
The provision of the connectionless data service in B-ISDNs is realized by means of ATM switched
capabilities and Connectionless Service Functions (CLSF). The ATM switched capabilities support the
transport of connectionless data units in B-ISDNs between specific functional groups CLSF able to handle
the connectionless protocol and to realize the adaptation of the connectionless data units into ATM cells to
be transferred in a connection-oriented environment. The CLSF functional groups may be located outside
a B-ISDN, in a private connectionless network or in a specialized service provider, or inside a B-ISDN.
The relevant reference configuration for the provision of the connectionless data service in a B-ISDN is
depicted in figure 1.
B-ISDN
custom er
CLSF
  Specialized
S /T
B B
service provider
M
CLSF
P
B-ISDN
ATM switched
  capabilities
S /T
M
B B
CLSF
CLSF
  Specialized
    Private
service provider
connectionless
B-ISDN
   network
custom er
CLSF: Connectionless Service Function.
M, P, S , T : Reference points.
B B
Figure 1: Reference configuration for the provision of the CL data service in B-ISDN
The ATM switched capabilities are performed by the ATM nodes (ATM switch/cross-connect) which
realize the ATM transport network. The CLSF functional group terminates the B-ISDN connectionless
protocol and includes functions for the adaptation of the connectionless protocol to the intrinsically
connection-oriented ATM layer protocol and functions for the adaptation of the CL protocols using up to
9 2766 octets (9 188 user information plus protocol control information), variable size PDUs to the fixed
size, 48 octet ATM-SDUs and to the specific error characteristics (possible cell loss, possible burst cell
loss) of the ATM networks. These latter functions are those performed by the ATM Adaptation layer
type 3/4 (AAL 3/4), while the former ones are those related to the layer directly above the AAL denoted
Connectionless Layer (CLL) and performed by the Connectionless Network Access Protocol (CLNAP),
Connectionless Network Interface Protocol (CLNIP) and related Connectionless Layer Routeing &
Relaying (CLLR&R) functions, respectively.

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The CLL protocols include functions such as routeing, addressing, QoS selection. In order to perform the
routeing of CL data units, the CLSF has to interact with the control/management planes of the underlying
ATM network.
CLSF CLSF
P P or M
ATM ATM
switched switched
capabilities capabilities
Option A Option B
CLSF and ATM switched capabilities CLSF and ATM switched capabilities
implemented in the same equipm ent implemented in different equipment
Figure 2: Implementation of CLSF and ATM switched capabilities
The general protocol structure for the provision of ConnectionLess (CL) data service in B-ISDN is shown
in figure 3.
Custom er terminal ATM switched capabilities
ATM switched capabilities
    equipm ent   plus transit C LSF
   plus access CLSF
CLLR&R CLLR&R
CLNAP
CLNAP CLNIP CLNIP CLNIP
ATM node
ATM node
AAL 3/4 AAL 3/4 AAL 3/4 AAL 3/4 AAL 3/4
ATM ATM
ATM ATM ATM ATM ATM
Physical Physical
Physical Physical Physical Physical Physical
NOTE: A null (empty) Service Specific Convergence Sublayer (SSCS) is used.
Figure 3: General protocol structure for provision of CBDS in B-ISDN
The CLSF functional group can be considered implemented in the same equipment together with the ATM
switched capabilities as depicted in figure 2 (option A). In this case there is no need to define the interface
at the P reference point. CLSF functional group and ATM switched capabilities can be implemented also
in separate equipment (figure 2, option B). In this case interfaces shall be defined at the M or P Reference
Points (refer to ITU-T Recommendations I.324 [7] and I.327 [8]) depending on whether the CLSF is
located outside or inside the B-ISDN.
4.3 Connectionless server functional description
A Connectionless Server (CLS) is a network element which includes the CLSF. It interfaces ATM nodes or
other CLSs at the P/M reference points and B-ISDN customer equipment at S /T reference points. The
B B
CLS may perform among others the following functions (see also figure 4):
- Connection Functions (CF), which include all port-related functionalities for the termination of ATM
connections;
- Connectionless Handling Functions (CLHF), which include all the service-specific functions required
for the support of connectionless service provision in B-ISDN. In general they are related to the
network integrity issues (e.g. address validation/screening, access class enforcement) and to
relaying issues (e.g. routeing, group address handling);

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- Control Functions (CTF) are related to connection/resource handling and service processing; the
information necessary to effect control over the communication resources in the server can be
exchanged with other network elements through signalling or management protocols;
- Operation And Maintenance (OAM) functions.
NOTE: Transit CLSs do not contain access termination functions and access connection
control functions.
Connection functions
ATF
NTF
ATF
NTF
ATF NTF
Connectionless service handling functions
Other service
CLMF
specific
functions
Control functions
Network
Access
Connection & resource
connection
connection
handling functions
control
control
Operation and m aintenance functions
Figure 4: Connectionless server functional model
The Access Termination Functions (ATF) blocks contain the functions required to receive/transmit
information from/to a B-ISDN user possibly through an ATM node. The block performs protocol
functionalities corresponding to physical, ATM, AAL type 3/4 protocols and CLNAP.
The Network Termination Functions (NTF) blocks include the functions required to receive/transmit
information from/to a CLS possibly through an ATM node. The block performs protocol functionalities
corresponding to physical, ATM, AAL type 3/4 protocols and CLNIP.
Both ATF and NTF blocks include functions for terminating ATM connections and some CL services
specific functions. The description of the functional architecture of the ATF and NTF blocks relevant to the
specification of CLAI and Connectionless Network Interface (CLNI), respectively, is given in
subclause 4.4.
The Connectionless Handling Functions (CLHF) are located partly in the ATF/NTF blocks and partly in the
Connectionless Mapping Functions (CLMF) block.
The CLMF block (see figure 5) performs routeing, protocol conversion between access and network
terminations and group address handling functions, i.e. CLLR&R functions. The CLMF block (as shown in
figure 5) is composed of the following functional blocks:
- Group Address Handling Functions (GAHF);
- Protocol Conversion Functions (PCF); and
- Routeing functions.

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PCF (Protocol
GAHF (G roup Address
Conversion Functions)
Handling F unctions)
Routeing functions
CLMF
Figure 5: CLMF Block
The GAHF block handles both group-addressed CLNAP-PDUs and group-addressed CLNIP-PDUs whose
resolution is requested by this CLS. This functional block performs group-addressed data units handling,
resolving the group address into its associated individual addresses. The resolved individual addresses
may identify end users served either by this CLS or by a remote CLS.
The PCF block performs protocol conversion between the Access Termination Functions (ATF) and the
Network Termination Functions (NTF). In particular, it provides all the relevant information necessary to
properly create a CLNIP-PDU from a CLNAP-PDU or to recover a CLNAP-PDU from the received
CLNIP-PDU.
The functions denoted as routeing, on the basis of the destination address of the data unit to be forwarded
across a User Network Interface (UNI) or Network Node Interface (NNI), select the proper outgoing
physical link and Virtual Path Identi
...