ETSI ETS 300 479-1 ed.1 (1998-02)

Network Aspects (NA); Connectionless Broadband Data Service (CBDS) over Asynchronous Transfer Mode (ATM); Protocol specification at the Network Node Interface (NNI); Part 1: Specification

DE/NA-053206

Omrežni vidiki (NA) – Nepovezavna širokopasovna podatkovna storitev (CBDS) z asinhronim prenosnim načinom (ATM) – Specifikacija protokola na vmesniku omrežnega vozlišča (NNI) – 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 300 479-1 E1:2003 - Network Aspects (NA); Connectionless Broadband Data Service (CBDS) over Asynchronous Transfer Mode (ATM); Protocol specification at the Network Node Interface (NNI); Part 1: Specification

Standards Content (Sample)

SLOVENSKI STANDARD
SIST ETS 300 479-1 E1:2003
01-december-2003
2PUHåQLYLGLNL1$±1HSRYH]DYQDãLURNRSDVRYQDSRGDWNRYQDVWRULWHY&%'6]
DVLQKURQLPSUHQRVQLPQDþLQRP$70±6SHFLILNDFLMDSURWRNRODQDYPHVQLNX
RPUHåQHJDYR]OLãþD11,±GHO6SHFLILNDFLMD
Network Aspects (NA); Connectionless Broadband Data Service (CBDS) over
Asynchronous Transfer Mode (ATM); Protocol specification at the Network Node
Interface (NNI); Part 1: Specification
Ta slovenski standard je istoveten z: ETS 300 479-1 Edition 1
ICS:
33.040.40 Podatkovna komunikacijska Data communication
omrežja networks
SIST ETS 300 479-1 E1:2003 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST ETS 300 479-1 E1:2003

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SIST ETS 300 479-1 E1:2003
EUROPEAN ETS 300 479-1
TELECOMMUNICATION February 1998
STANDARD
Source: NA Reference: DE/NA-053206
ICS: 33.020
Key words: ATM, Broadband, CBDS, NNI
Network Aspects (NA);
Connectionless Broadband Data Service (CBDS)
over Asynchronous Transfer Mode (ATM);
Protocol specification at the Network Node Interface (NNI);
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 300 479-1: 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.7
4 Framework for the provision of CBDS.8
5 Layer service and functions provided by the Connectionless Layer (CLL).8
6 Protocol for the support of the CBDS on B-ISDN at the NNI .8
6.1 Overview .8
6.2 Protocol stack .9
6.3 Layer service expected from the AAL.9
6.4 CLNIP-PDU structure and encoding.10
6.4.1 Destination Address (DA).11
6.4.2 Source Address (SA).11
6.4.3 Protocol Identifier (PI).12
6.4.4 PAD length .12
6.4.5 Quality of Service (QoS).12
6.4.6 Cyclic Redundancy Check (CRC) Indication Bit (CIB) .12
6.4.7 Header Extension Length (HEL) .12
6.4.8 Reserved .12
6.4.9 Header extension .12
6.4.10 HE Post-PAD.13
6.4.11 User Information.13
6.5 Error conditions.13
6.5.1 In the case of encapsulation.13
6.5.2 In the case of non-encapsulation .13
7 Mapping.14
7.1 Mapping between CLNAP and CLNIP .14
7.2 CLNIP procedures .16
7.2.1 Application rules for encapsulation and non-encapsulation .16
7.2.2 Encapsulation/decapsulation and non-encapsulation mechanisms.16
7.2.3 Derivation of the encapsulating CLNIP-PDU fields .17
7.2.4 Derivation of the non-encapsulating CLNIP-PDU fields.18
7.2.5 Interaction between CLNIP entity and Connectionless Layer Routeing &
Relaying (CLLR&R) entity .18
7.2.6 primitives between CLNIP and CLLR&R entities .19
8 Group addressed PDU handling .19
8.1 Definitions .20
8.1.1 Group address agent (GAA).20
8.1.2 Nested group address agent (NGAA) .20
8.1.3 Architectural configurations for Group Addressing.20
8.2 Centralized database approach.21
8.2.1 Transport.21
8.2.2 Adding a new member to the group .22
8.3 Centralized database in conjunction with one level of NGAs.22
8.3.1 Definition .22
8.3.2 Transport.23
8.3.3 Adding a new member to the group .24

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Annex A (informative): Interworking conditions with Switched Multi-megabit Data Service (SMDS):
network aspects. 25
A.1 MID . 25
A.2 PI . 25
A.3 HE. 25
A.4 Streaming mode . 25
Annex B (informative): Procedures. 26
B.1 Receiving procedure. 26
B.2 Sending procedures. 26
Annex C (informative): Bibliography . 27
History. 28

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ETS 300 479-1: 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 protocol specification at the Network
Node Interface (NNI), for the Connectionless Broadband Data Service (CBDS) over Asynchronous
Transfer Mode (ATM), as identified below:
Part 1: "Specification";
Part 2: "Connectionless Network Interface Protocol (CLNIP) 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 300 479 describes the protocol to support the Connectionless Broadband Data
Service (CBDS) at the Network Node Interface (NNI) of Broadband Integrated Services Digital Network
(B-ISDN) in accordance with:
- ETS 300 217 [1], which details the stage 1 aspects for the CBDS;
- ETS 300 478-1 [4], which provides the general framework to provide CBDS over Asynchronous
Transfer Mode (ATM) and the protocol specification to support the service at the UNI.
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] ETS 300 217 (1992): "Network Aspects (NA); Connectionless Broadband Data
Service".
[2] CCITT Recommendation E.164 (1991): "Numbering plan for the ISDN era".
[3] ETS 300 349: "Broadband Integrated Services Digital Network (B-ISDN);
Asynchronous Transfer Mode (ATM) Adaptation Layer (AAL) specification -
type 3/4".
[4] ETS 300 478-1: "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".
3 Abbreviations
For the purposes of this ETS, the following abbreviations apply:
AAL ATM Adaptation Layer
ATF Access Termination Functions
ATM Asynchronous Transfer Mode
BAsize Buffer Allocation size
B-ISDN Broadband Integrated Services Digital Network
BOM Beginning Of Message
BTag Beginning Tag
CBDS Connectionless Broadband Data Service
CIB CRC Indication Bit
CLAI Connectionless Access Interface
CLCP Connectionless Convergence Protocol
CLL Connectionless Layer
CLLR&R Connectionless Layer Routeing & Relaying
CLNAP Connectionless Network Access Protocol
CLNI Connectionless Network Interface
CLNIP Connectionless Network Interface Protocol
CLS Connectionless Server
CLSF Connectionless Service Function
CPCS Common Part Convergence Sublayer
CPI Common Part Indicator
CRC Cyclic Redundancy Check
DA Destination Address
EI Encapsulating Indicator
EOM End Of Message
GA Group Address
GAA Group Address Agent

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HE Header Extension
HEL Header Extension Length
IWU Interworking Unit
MID Multiplexing Identification
NGA Nested Group Address
NGAA Nested Group Address Agent
NNI Network Node Interface
NTF Network Termination Functions
OAM Operation Administration and Maintenance
PDU Protocol Data Unit
PI Protocol Identifier
QoS Quality of Service
SA Source Address
SAP Service Access Point
SAR Segmentation And Reassembly
SDU Service Data Unit
SMDS Switched Multi-megabit Data Service
SSCS Service Specific Convergence Sublayer
SSM Single Segment Message
UNI User Network Interface
4 Framework for the provision of CBDS
See ETS 300 478-1 [4], clause 4.
5 Layer service and functions provided by the Connectionless Layer (CLL)
See ETS 300 478-1 [4], clause 5.
6 Protocol for the support of the CBDS on B-ISDN at the NNI
6.1 Overview
The Connectionless Network Interface Protocol (CLNIP) supports the CBDS as specified in
ETS 300 217 [1] between Connectionless Servers (CLSs) inside a network operator's domain and
between two network operators' domains.
NOTE: It is assumed that this protocol applies to all cases. Additional functionalities may be
needed for the support of this service within a network operator domain.
The CLNIP provides two modes of operation: encapsulation and non-encapsulation. For the conditions for
the selection of the mode of operation and the mechanisms to be applied in either mode see clause 7.
The CLNIP shall be applied at the Connectionless Network Interface (CLNI), as shown in figure 1.

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CLNI at P CLNI at P
CLS A TM capabilities CLS
CLLR& R
CLL& R
CLNIP CLNIP
AAL 3/4 AAL 3/4
ATM
AT M
A TM c apabilities
Physical Physical
NOTE: A null (empty) Service Specific Convergence Sublayer (SSCS) is used.
Figure 1: Network and protocol architecture
6.2 Protocol stack
The protocol stack for supporting the transfer of connectionless data between CLSs is depicted in figure 2.
The CLNIP uses the ATM Adaptation Layer (AAL) type 3/4 unassured service (using null SSCS) and
includes the necessary functionality to provide the CLL service. For structure and encoding of AAL type
3/4 (Segmentation And Reassembly (SAR) sublayer and Common Part Convergence Sublayer (CPCS))
see ETS 300 349 [3].
CLNIP
AAL SAP
AAL type 3/4
ATM
Physical
NOTE: A null (empty) SSCS is used.
Figure 2: Protocol stack for CLNIP
6.3 Layer service expected from the AAL
The CLNIP expects the AAL connection to provide for the transparent and sequence-preserving transfer
of CLNIP Protocol Data Units (CLNIP-PDUs) between two CLNIP entities when accessing a point-to-point
AAL connection. This transfer is operated in an unassured manner, i.e. lost or corrupted data units are not
retransmitted (Unassured Operation).
The information transfer between the CLNIP entity and the AAL entity can be performed in a message
mode or streaming mode.

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The information exchanged between the AAL entities and the CLNIP entities across the AAL-Service
Access Point (AAL-SAP) uses the following primitives:
a) AAL-UNITDATA.request (Interface Data, More (see note), Maximum Length (see note));
b) AAL-UNITDATA.indication (Interface Data, More (see note), Maximum Length (see note),
Reception Status);
c) AAL-U-Abort.request (see note);
d) AAL-U-Abort.indication (see note);
e) AAL-P-Abort.indication (see note).
NOTE: This primitive/parameter is used in streaming mode only.
The CLNIP shall not make use of the Corrupted Data delivery option which may be supported by the AAL
type 3/4 protocol i.e. the optional Reception Status parameter in the AAL-UNIT-DATA -indication primitive
is not used.
A detailed description of the primitives and parameters is provided in ETS 300 349 [3].
6.4 CLNIP-PDU structure and encoding
The detailed structure of the Connectionless Network Interface Protocol-Protocol Data Unit (CLNIP-PDU)
is illustrated in figure 3.

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Bit position
32-bit word num ber
1
32 16
De stination ad dress (m ost significant word)
1
Destination address (least sig nificant word)
2
CLCP
Source address (m ost significant word)
3
hea der
Source address (lea st significant word)
CLNIP-PDU
4
 header
PAD
CIB HEL
QoS
 PI
le ngth
(1b ) (3b) Reserved
5
(4 b)
(6b)
(2b)
H eade r-e xtensio n
20
o cte ts
Header-extension p ost-PAD
10
User inform ation
PAD (0 - 3 octets)
Optional 32-bit CRC
N
(nb): length of field (n) in bits.
CLC P he ader: Connectionless Convergence Proto co l H eade r
NOTE 1: The Header Extension (HE) Post-PAD is only present when encapsulation applies.
NOTE 2: The order of transmission is from left to right and from top to bottom.
Figure 3: Structure of the CLNIP-PDU
The CLNIP-PDU contains the following fields:
6.4.1 Destination Address (DA)
This 8-octet field contains a 4-bit "address-type" subfield, followed by the 60-bit "address" subfield. The
"address-type" subfield indicates whether the "address" subfield contains a publicly administered 60-bit
individual address or a publicly administered 60-bit group address. Encoding of the "address-type" subfield
is described in ETS 300 478-1 [4], annex A.
The information included in the "address" subfield indicates to which CLNIP entity(ies) the CLNIP-PDU is
destined. The structure of the "address" subfield is modelled according to CCITT Recommendation
E.164 [2]. Encoding of the "address" subfield is described in ETS 300 478-1 [4], annex A.
6.4.2 Source Address (SA)
This 8-octet field contains a 4-bit "address-type" subfield, followed by the 60-bit "address" subfield. The
"address-type" subfield indicates that the "address" subfield contains a publicly administered 60-bit
individual address. Encoding of the "address-type" subfield is described in ETS 300 478-1 [4], annex A.

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The "address" subfield indicates the Connectionless Network Access Protocol (CLNAP) entity that
originated the CLL user data packet included in the CLNIP-PDU. The structure of the "address" subfield is
modelled according to CCITT Recommendation E.164 [2]. Encoding of the "address" subfield is described
in ETS 300 478-1 [4], annex A.
6.4.3 Protocol Identifier (PI)
If encapsulation is performed, this 6-bit field takes one of the values [44-47] and is used to indicate that
the CLNIP-PDU is an encapsulating one. If the encapsulating CLNIP-PDU carries CLL user data the value
44 shall be used. The values [45-47] are reserved (see note).
NOTE: In the future these values may also be used to identify encapsulated user data transfer
associated with additional functions.
If encapsulation is not performed, the field has the same coding and meaning as in the CLNAP-PDU sent
by the originating CLNAP entity.
At an inter-operator domain NNI the sender is responsible for the encoding of the PI field of PDUs carrying
user data with a value that is appropriate for the network directly across the interface. On the basis of
bilateral operator's agreement, the PI values outside the range [44-47] may be used by the sending CLS.
Currently identified values are 50 and 51 which indicate that the CLNIP-PDU is encapsulating. In the
absence of bilateral agreement the sender shall use the value 44 when the CLNIP-PDU carries CLL user
data.
6.4.4 PAD length
This 2-bit field indicates the length of the PAD field (0-3 octets). The number of PAD octets is such that
the total length of the "User Information" field and the PAD field together is an integral multiple of 4 octets.
This field is always coded to 0 in case encapsulation is performed.
6.4.5 Quality of Service (QoS)
This 4-bit field is used to indicate the QoS requested for the CLNIP-PDU. In case of non-encapsulation
this field has the same coding and meaning as in the CLNAP-PDU sent by the originating service user. In
case of encapsulation the value shall be coded to 0.
6.4.6 Cyclic Redundancy Check (CRC) Indication Bit (CIB)
This 1-bit field indicates the presence (CIB = 1) or absence (CIB = 0) of a 32-bit CRC. In case
encapsulation is performed, this field shall always be coded to "0" as it is not necessary to use the CRC
for the encapsulating PDU.
6.4.7 Header Extension Length (HEL)
This 3-bit field indicates the number of 32-bit words in the HE field.
In case encapsulation is performed this field shall be set to "3". In case of non-encapsulation this field
shall be set in the range [0-5].
6.4.8 Reserved
This 16-bit field is reserved for future use. Its default value is "0". At least 8 bits will be used for enhanced
multicasting which is outside the scope of this document.
6.4.9 Header extension
This content of this field is not constrained by this ETS.
In case encapsulation is performed its length shall be 12 octets. In case of non-encapsulation its length is
in the range [0-20] octets and is indicated by the value of the HEL field.

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6.4.10 HE Post-PAD
In case encapsulation is performed, this field has a length of 8 octets. The first octet is dedicated to the
transfer of the protocol version number and shall be set to "1" for the equipment implementing this release
of this ETS. The content of the remaining 7 octets is not constrained by this ETS.
This HE Post-PAD field shall always be absent if encapsulation is not performed.
6.4.11 User Information
This field is of variable length, in the range of [24-9 236] (see note) octets when encapsulating and in the
range of [0-9 188] octets when non-encapsulating.
NOTE: 9 188 (SDU) + 40 (HDR) + 4 (CRC) + 4 (Alignment Header).
In case encapsulation is performed, this field carries the encapsulated CLNAP-PDU + Alignment Header
(see figure 8) (4 octets long). The user information field length shall be an integer multiple of 4 octets. The
content of the Alignment Header shall not be checked.
In case of non-encapsulation, the field carries the source Service Data Unit (SDU).
6.5 Error conditions
6.5.1 In the case of encapsulation
This subclause applies to CLNIP-PDUs which are identified as encapsulating PDUs only.
Various errors may occur in receiving CLNIP-PDUs. Whenever one of the following conditions is
encountered at the receiver, the respective CLNIP-PDU shall be discarded:
- Invalid address format;
- CLNIP SA different to CLNAP-PDU SA;
- CLNIP DA different to CLNAP-PDU DA in the case that the latter is an individual address;
- PAD length different from 0;
- QoS field other than 0;
- CLNIP CIB = 1;
- Value of HEL field not equal 3;
- PI field content different from the allowed range (see subclause 6.4.3);
- Length of the CLNIP-PDU is not an integral multiple of 4 octets.
6.5.2 In the case of non-encapsulation
This subclause applies to CLNIP-PDUs which are identified as non-encapsulating by means of the PI field.
Various error conditions may occur in receiving CLNIP-PDUs. Whenever one of the following conditions is
encountered at the receiver, the respective CLNIP-PDU shall be discarded:
- Invalid address format;
- PAD length such that the total length of user information and PAD fields is not a integral multiple of
4 octets;
- Value of HEL field not in the range of 0 to 5 inclusive;
- Length of the CLNIP-PDU is not an integral multiple of 4 octets.

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7 Mapping
7.1 Mapping between CLNAP and CLNIP
A CLS includes one or more of the following general types of functions.
For a given CLNAP/CLNIP-PDU, each CLS involved performs one of these types of functions.
a) Originating functions
CLLR&R
CLNAP CLNIP
AAL3/4 AAL3/4
ATM ATM
Physical Physical
CLAI CLNI
Figure 4
Originating functions get CLNAP-PDUs from customer equipment via a Connectionless Access Interface
(CLAI) and forward corresponding CLNIP-PDUs (either encapsulating or non-encapsulating ones) to
another CLS via a CLNI.
b) Terminating functions
CLLR&R
CLNIP CLNAP
AAL3/4 AAL3/4
ATM ATM
Physical
Physical
CLNI CLAI
Figure 5
Terminating functions get (encapsulating and/or non-encapsulating) CLNIP-PDUs from another
Connectionless Server (CLS) via a Connectionless Network Interface (CLNI) and forward corresponding
CLNAP-PDUs to customer equipment via a CLAI.

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c) Transit functions
CLLR&R
CLNIP CLNIP
AAL3/4
AAL3/4
ATM ATM
Physical Physical
CLNI
CLNI
Figure 6
Transit functions get encapsulating and/or non-encapsulating CLNIP-PDUs from another CLS via a CLNI
and forward corresponding CLNIP-PDUs to another CLS via another CLNI. If the next CLS belongs to
another operator's domain, non-encapsulating CLNIP-PDUs are encapsulated before they are forwarded.
d) Access-only functions
CLLR&R
CLNAP CLNAP
AAL3/4
AAL3/4
ATM ATM
Physical Physical
CLAI
CLAI
Figure 7
Access-only functions get CLNAP-PDUs from customer equipment via a CLAI and forward them to other
customer equipment via another CLAI.
Additional definitions:
- access functions: Common name for originating, terminating and access-only functions;
- originating CLAI: CLAI over which incoming CLNAP-PDUs are received;
- terminating CLAI: CLAI over which outgoing CLNAP-PDUs are transmitted;
- originating (ingress) CLNI: CLNI over which incoming CLNIP-PDUs are received;
- terminating (egress) CLNI: CLNI over which outgoing CLNIP-PDUs are transmitted.

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7.2 CLNIP procedures
7.2.1 Application rules for encapsulation and non-encapsulation
a) At CLNIs between network operators, encapsulation is always used for both group and individually
addressed PDUs.
b) At CLNIs within a single operator's network, encapsulation and/or non-encapsulation may be used
by the network operator.
Depending on the mechanism used within the operator's domain to which a CLS belongs, one or both
mechanisms shall be supported by a certain type of functions:
1) if encapsulation is used within the operator's domain, the originating functions encapsulate every
CLNAP-PDU.
In case of an intra operator CLNI, the non-encapsulation mechanism may alternatively be used by
the originating functions;
2) if encapsulation is used within the operator's domain, the terminating functions shall decapsulate
every CLNIP-PDU.
Terminating functions in an operator's domain where the non-encapsulation mechanism is used
shall differentiate between encapsulating and non-encapsulating CLNIP-PDUs and appropriately
handle them. Decapsulation takes place if an encapsulating PDU is received;
3) if encapsulation is used within the operator's domain, the transit functions forward CLNIP-PDUs
without being actively involved in the encapsulation mechanism. When encapsulation is not used
within the operator's domain, the transit functions forward the CLNIP-PDU without being actively
involved except for the following case:
If the originating CLNI is an intra domain CLNI and the terminating CLNI is an inter domain CLNI,
the transit functions shall differentiate between encapsulating and non-encapsulating CLNIP-PDUs:
non-encapsulating CLNIP-PDUs shall be mapped to encapsulating CLNIP-PDUs before they are
forwarded;
4) access-only functions forward CLNAP-PDUs without applying either mechanism.
7.2.2 Encapsulation/decapsulation and non-encapsulation mechanisms
When encapsulation is performed, the CLS functions add a CLNIP-PDU header plus a 4-octet Alignment
Header to the beginning of the CLNAP-PDU or the non-encapsulated CLNIP-PDU. The values of the
fields of the CLNIP-PDU header are either derived by the CLS functions or fixed due to protocol
specifications.
The decapsulation mechanism strips the header plus the Alignment Header from the CLNIP-PDU in order
to recover the CLNAP-PDU.
When non-encapsulation is performed inside the operator's domain, the CLNAP-PDU is regarded as a
CLNIP-PDU and transparently transmitted within the network. Therefore, no special mechanism is
required. Since the encapsulation mechanism is not performed, the CLNIP-PDU is equal to the
CLNAP-PDU.

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