ETSI ETS 300 099 ed.1 (1992-08)

SLOVENSKI STANDARD
01-december-2003
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Integrated Services Digital Network (ISDN); Specification of the Packet Handler access
point Interface (PHI)
Ta slovenski standard je istoveten z: ETS 300 099 Edition 1
ICS:
33.080 Digitalno omrežje z Integrated Services Digital
integriranimi storitvami Network (ISDN)
(ISDN)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN ETS 300 099
TELECOMMUNICATION August 1992
STANDARD
Source: ETSI TC-NA Reference: T/NA2(89)10
ICS: 33.080
ISDN, access, interface
Key words:
Integrated Services Digital Network (ISDN);
Specification of the
Packet Handler access point Interface (PHI)
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
F-06921 Sophia Antipolis CEDEX - FRANCE
Postal address:
650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
Office address:
c=fr, a=atlas, p=etsi, s=secretariat - secretariat@etsi.fr
X.400: Internet:
Tel.: +33 92 94 42 00 - Fax: +33 93 65 47 16
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 1992. All rights reserved.
New presentation - see History box

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ETS 300 099: August 1992
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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ETS 300 099: August 1992
Contents
Foreword.11
1 Scope .13
1.1 Implementation alternatives for ISDN packet mode services and applicability of this
specification.13
1.2 ISDN packet mode services supported .13
1.3 Local and remote access to the PHI .13
2 Normative references .14
3 Definitions and abbreviations.16
3.1 Definitions.16
3.2 Abbreviations.18
4 Reference configuration and functional model .19
4.1 Reference configuration.19
4.2 Basic functional model.21
4.3 Functional model for remote access to the PHI.23
5 Services supported by the PHI specification .25
5.1 Basic services.25
5.1.1 Services provided on the B-channel .25
5.1.1.1 Semipermanent access.25
5.1.1.2 Switched access . 26
5.1.2 Services provided on the D-channel (case B).26
5.1.2.1 Semipermanent access.26
5.1.2.2 PLL access. 27
5.1.2.3 Switched access . 27
5.2 Detailed service aspects.27
5.2.1 Notification of incoming calls.27
5.2.1.1 No Notification Class.28
5.2.1.2 Conditional Notification Class.28
5.2.2 Mapping of information elements .28
5.2.3 Access connection clearing .28
5.2.4 Access collision.29
5.2.5 Cause mappings .29
5.3 Numbering, addressing and terminal selection .29
5.3.1 Numbering and addressing.29
5.3.2 Terminal selection and compatibility checking .30
5.3.3 Directory number and services association.31
5.4 Services cross-reference and conformance statement for the PHI .31
6 Basic interface structure .33
6.1 General.33
6.2 Interface architecture for single-PRA PHI.33
6.2.1 Local PHI access .33
6.2.2 Remote PHI access.33
6.3 PHI channel types .36
6.3.1 D64-channel.36
6.3.2 Bb-channels (case A and case B).39
6.3.3 Bd-channels.39
6.3.3.1 Data transfer. 41
6.3.3.2 Link layer management .41

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ETS 300 099: August 1992
7 Interface configuration .44
7.1 Frame handler function at the CRF-S .44
7.2 Multi-PRA PHI configuration .44
8 Operations, administration and maintenance (OA&M).44
8.1 General .44
8.1.1 Scope.44
8.1.2 Definitions.44
8.1.3 Principles.44
8.2 Layer 1 OA&M requirements.45
8.2.1 Administration .45
8.2.1.1 Provisioning of semi-permanent Bb-channels.45
8.2.1.2 Provisioning of semi-permanent Bd-channels.45
8.2.2 Operations and maintenance .45
8.2.2.1 Primary rate access.45
8.2.2.2 Establishment and release of switched Bd-channels due
to operational requirements .45
8.2.2.3 Re-establishment of dynamically provisioned
semi-permanent Bd-channels in case of failure.45
8.3 Layer 2 OA&M requirements.46
8.3.1 Bb-channels .46
8.3.2 Bd-channels .46
8.3.2.1 Administration.46
8.3.2.2 Operations .46
8.3.2.2.1 General status and performance
monitoring.46
8.3.2.2.2 Load sharing .47
8.3.2.3 Maintenance.47
8.3.3 D64-channel.47
8.4 Layer 3 OA&M requirements.47
8.4.1 Service support .47
8.4.1.1 CCITT Recommendation X.25 Packet Layer Procedures
(PLP).47
8.4.1.2 PVCs on the D-channel .47
8.4.2 Signalling (D64 and Bd-inband).48
8.4.2.1 Administration.48
8.4.2.2 Operations .48
8.4.2.2.1 D64-signalling.48
8.4.2.2.2 Bd-inband signalling .48
8.4.2.3 Maintenance.48
8.4.2.3.1 D64-signalling.48
8.4.2.3.2 Bd-inband signalling .48
9 Frame multiplexing on the Bd-channels.48
9.1 Principle .48
9.2 Address field layout.49
9.3 Subscriber data links .51
9.4 Signalling data link.51
9.4.1 The DLCI value of the signalling data link.51
9.4.2 Establishment of the signalling data link.52
9.4.3 Signalling data link failure .52
9.4.4 Recovery of the signalling data link .52
9.5 Switchover and concentration.53
9.6 Reset procedures.53
9.7 Bd-channel continuity check.53
9.7.1 HDLC Flag continuity check procedure.53
9.7.2 Management frame continuity check procedure.54
9.7.2.1 Both-way procedure description.54
9.7.2.2 One-way procedure description .54
9.7.2.3 Management frame layouts .55

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ETS 300 099: August 1992
9.7.2.4 Parameter set. 55
9.8 Connection verification procedure .56
9.9 Peer busy procedures .56
9.10 Default timer values.56
10 PHI signalling .57
10.1 General introduction .57
10.1.1 Signalling procedures.57
10.1.2 Signalling messages.57
10.1.3 Information Elements.57
10.2 B-channel services, switched, case A . 58
10.2.1 Signalling messages.58
10.2.1.1 Call proceeding .59
10.2.1.2 Connect . 59
10.2.1.3 Connect acknowledge.59
10.2.1.4 Disconnect.59
10.2.1.5 Release.60
10.2.1.6 Release complete.60
10.2.1.7 Setup.60
10.2.1.8 Status.61
10.2.1.9 Status enquiry .61
10.2.2 Case A, procedures for an outgoing call (CRF-P to PH) .61
10.2.3 Case A, procedures for an incoming call (PH to CRF-P).62
10.2.4 Case A, procedures for call clearing .63
10.3 B-channel services, switched, case B . 63
10.3.1 Signalling messages.63
10.3.1.1 Call proceeding .64
10.3.1.2 Connect . 64
10.3.1.3 Connect acknowledge.64
10.3.1.4 Disconnect.65
10.3.1.5 Release.65
10.3.1.6 Release complete.65
10.3.1.7 Setup.66
10.3.1.8 Status.66
10.3.1.9 Status enquiry .67
10.3.2 Case B, procedures for an outgoing call (CRF-P to PH) .67
10.3.3 Case B, procedures for an incoming call (PH to CRF-P).68
10.3.4 Case B, procedures for call clearing .69
10.4 Switched Bd-channels .69
10.4.1 Signalling messages for circuit mode procedures.69
10.4.1.1 Connect .70
10.4.1.2 Setup.70
10.4.2 Signalling messages for packet mode procedures.70
10.4.2.1 Connect . 70
10.4.2.2 Setup.71
10.4.3 Procedures for Bd-channels established by the CRF-S (CRF-P to PH).71
10.4.4 Procedures for Bd-channels established by the PH (PH to CRF-P).72
10.4.5 Procedures for Bd-channel access connection clearing.73
10.5 D-channel services, switched, case B. 73
10.5.1 Signalling messages.73
10.5.1.1 Connect .74
10.5.1.2 Release.74
10.5.1.3 Release complete.74
10.5.1.4 Setup.75
10.5.1.5 Status.76
10.5.2 Procedures for data link establishment by the CRF-S (CRF-S to PH) .76
10.5.3 Procedures for data link establishment by the PH (PH to CRF-S).77
10.5.4 Procedures for data link disconnection .79
10.5.5 Procedures after receipt of a STATUS message .80
10.6 Restart on the D64-channel. 80

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10.6.1 Signalling messages .80
10.6.1.1 Restart .81
10.6.1.2 Restart acknowledge .81
10.6.1.3 Status.81
10.6.2 Restart procedure .81
10.7 The timers T320, TPHI, TPH, and TCRF.82
11 Static and dynamic provisioning for PLL and semipermanent services.82
11.1 General Introduction.82
11.1.1 Signalling procedures.83
11.1.2 Signalling messages .83
11.1.3 Information elements .83
11.2 B-channel services, case A and case B, semipermanent .83
11.2.1 Static provisioning.83
11.2.2 Dynamic provisioning .83
11.3 Semipermanent Bd-channels.83
11.3.1 Static provisioning.83
11.3.2 Dynamic provisioning .83
11.3.3 De-registration of dynamically provisioned Bd-channels .84
11.4 D-channel services, PLL .84
11.4.1 PLL data link provisioning, static.84
11.4.2 Messages for dynamic provisioning of PLL data links .84
11.4.2.1 Register.85
11.4.2.2 Release complete.85
11.4.2.3 The linked identifier of the invoke component.85
11.4.2.4 The argument of the invoke component.86
11.4.2.5 The result of the return result component.86
11.4.2.6 The error value of the return error component.86
11.4.2.7 The parameter of the return error component.86
11.4.3 Procedures for PLL data link registration by the CRF-S (CRF-S to PH).86
11.4.4 Procedures for PLL data link registration by the PH (PH to CRF-S).87
11.4.5 Procedures for PLL data link de-registration.88
11.5 D-channel services, semipermanent.89
11.5.1 Semipermanent data link provisioning, static .89
11.5.2 Messages for dynamic provisioning of semipermanent data links.89
11.5.3 Procedures for semipermanent data link registration .89
11.5.4 Procedures for semipermanent data link de-registration .90
12 Exception handling.90
12.1 B-channel service (case A and B) .90
12.1.1 Outgoing call.90
12.1.2 Incoming call.90
12.1.2.1 Unsuccessful call .90
12.1.2.2 Premature clearing by remote terminal .90
12.1.2.3 No Bb-channel available .90
12.1.2.4 Data link disconnect.90
12.1.2.5 Acceptance of call on existing B-channel.91
12.1.3 Call collision .91
12.1.4 Data transfer phase.91
12.1.4.1 Subscriber disconnects data link .91
12.1.4.2 Bb-channel is cleared.91
12.1.4.3 Restart on PHI.91
12.2 Bd-channel establishment.91
12.2.1 Bd-channel establishment by the CRF-S.92
12.2.1.1 Corrupted "user-user" information element.92
12.2.2 Bd-channel establishment by the PH .92
12.2.2.1 Corrupted "user-user" information element.92
12.3 Switched D-channel service.92
12.3.1 Exception resolution using layer 2 procedures.92
12.3.1.1 Exception reporting on the user-network interface .92

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12.3.1.2 No exception reporting .93
12.3.1.3 DM-frame in the Bd-channel .93
12.3.2 Outgoing call.93
12.3.2.1 No Bd-channel available .93
12.3.2.2 Signalling data link disconnection.93
12.3.2.3 Data link establishment rejection.93
12.3.2.4 Repeated DLCI . 94
12.3.3 Incoming call.94
12.3.3.1 Unsuccessful call .94
12.3.3.2 Premature clearing by remote terminal .94
12.3.3.3 No Bd-channel available .95
12.3.3.4 Signalling data link disconnection.95
12.3.3.5 Acceptance of call on existing data link.95
12.3.3.6 Repeated "called party number".95
12.3.3.7 Repeated DLCI . 96
12.3.3.8 Data link disconnect.96
12.3.4 Call collision.96
12.3.5 Data transfer phase. 96
12.3.5.1 Subscriber disconnects data link .96
12.3.5.2 Bd-channel is cleared.96
12.3.5.3 Restart on PHI . 96
12.4 PLL or semipermanent D-channel service.96
12.4.1 Outgoing call.96
12.4.1.1 No Bd-channel available .96
12.4.1.2 SETUP with PLL (semipermanent) DLCI value.97
12.4.1.3 SABME with unknown DLCI.97
12.4.2 Incoming call.97
12.4.2.1 No Bd-channel available .97
12.4.2.2 SABME with unknown DLCI.97
12.4.3 Call collision.97
12.4.3.1 Call collision on network-user interface.97
12.4.3.2 Call collision on the Bd-channel .98
12.4.3.3 Exceeding the maximum number of data links .98
12.4.4 Data transfer phase. 98
12.5 PLL or semipermanent registration or de-registration.98
12.5.1 Registration and de-registration by the CRF-S.98
12.5.1.1 Data link disconnection.98
12.5.1.2 Repeated DLCI . 98
12.5.1.3 Unknown de-registration parameter.98
12.5.2 Registration or de-registration by the PH.99
12.5.2.1 Data link disconnection.99
12.5.2.2 Repeated "called party number".99
12.5.2.3 Repeated DLCI . 99
12.5.2.4 Unknown de-registration parameter.99
13 Additional information elements for PHI signalling.99
13.1 Coding rules .99
13.2 Coding of the additional information elements. 103
13.2.1 DLCI value. 103
13.2.2 Bd-channel reference number. 103
13.2.3 FH reference number. 104
13.2.4 Additional subscriber information . 104
13.2.5 Type of service . 105
13.2.6 Called party number . 105
13.2.7 Cause . 105
13.3 Coding of the facility Information Element. 106
13.3.1 Embedded information elements. 106
13.3.2 Operation value. 106
13.3.3 Error value. 107

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Annex A (informative): Requirements on the common channel signalling system .108
Annex B (informative): PHI signalling diagrams.108
B.1 Introduction.108
B.1.1 Conventions for the diagrams .108
B.2 B-channel services case A .111
B.2.1 B-channel establishment .111
B.2.2 B-channel disconnection.111
B.3 B-channel services case B .113
B.3.1 B-channel establishment .113
B.4 Dynamic Bd-channels.114
B.4.1 Bd-channel establishment.114
B.5 Data link establishment and release .117
B.5.1 D-channel data link establishment.117
B.5.2 D-channel link disconnection.119
B.6 Bd-channel establishment, semipermanent .120
B.7 Dynamic provisioning for D-channel PLL service.121
B.7.1 PLL data link registration .121
B.7.2 PLL data link de-registration.122
B.8 Dynamic provisioning for D-channel semi-permanent service .123
B.8.1 Semi-permanent data link registration .123
Annex C (informative): Additional information for PVCs on switched B-channel access (case B).124
C.1 Introduction.124
C.2 Procedure.124
C.2.1 Identification .124
C.2.2 B-channel establishment .124
C.2.3 Layer 2 and layer 3 establishment .124
C.2.4 Error procedures.124
C.2.5 Procedures for VCs on B-channels supporting PVCs.124
Annex D (informative): Multi-PRA configurations.125
D.1 Selection by using numbers.125
D.2 Selection by a hunting algorithm or a call deflection mechanism.125
D.3 Non-associated signalling.125
Annex E (informative): Switch-over and concentration procedures .126
E.1 Introduction.126
E.2 Applicability.126
E.3 Constraints .126
E.4 Procedures.126
E.4.1 Switchover procedures . 126
E.4.1.1 Switchover during link establishment .126

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E.4.1.2 Switchover of an established link . 127
E.4.2 Detailed procedure. 127
E.5 Traffic management considerations. 127
E.5.1 Bd-channel failure or malfunction . 127
E.5.2 Unexpected overload. 128
E.5.3 Concentration of under-loaded Bd-channels. 128
E.6 Modifications to the main part of the specification . 128
E.6.1 General interface architecture. 128
E.6.2 Data transfer . 128
E.6.3 Administration. 128
E.6.4 Load sharing. 128
E.6.5 Bd-inband signalling. 129
E.6.6 Switchover and concentration procedure. 129
E.6.7 Procedures for data link establishment by the CRF-S. 129
E.6.8 Bd-channel is cleared . 129
E.6.9 Call collision on the Bd-channel. 129
Annex F (informative): Reset procedures . 130
F.1 Procedure. 130
F.2 Coding. 130
Annex G (informative): Layer 2 SDL diagrams and state tables. 131
G.1 SDL diagrams. 131
G.2 Key to the state transition tables . 133
G.2.1 Definition of a cell of the state transition table. 133
G.2.2 Key to the contents of a cell. 133
G.3 State transition tables. 133
Annex H (normative): Coding of the BC and LLC information element. 135
H.1 BC information element for circuit switched bearer capability. 135
H.2 LCC information element for case A services. 135
H.3 BC information element for packet mode bearer capability . 137
H.4 BC information element in the Bd-channel signalling link. 137
Annex J (informative): SDL for management frame continuity check. 138
Annex K (normative): Selection mechanism for incoming calls. 142
History. 144

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ETS 300 099: August 1992
Foreword
This European Telecommunication Standard (ETS) has been prepared by the Network Aspects (NA)
Technical Committee of the European Telecommunications Standards Institute (ETSI).
In accordance with CCITT Recommendation I.130 [1], the following three level structure is used to
describe the telecommunications services by European public telecommunications operators under the
pan-European Integrated Services Digital Network (ISDN):
- Stage 1: is an overall service description, from the user's standpoint;
- Stage 2: identifies the functional capabilities and information flows needed to support the service
described in stage 1; and
- Stage 3: defines the signalling system protocols and switching functions needed to implement the
service described in stage 1.
This ETS defines a network-internal interface for the provision of ISDN packet mode services as defined in
ETS 300 048 [7] (derived from CCITT Recommendation I.232 [16]), ETS 300 049 [8] (derived from CCITT
Recommendation I.232 [16]) (stage 1) and ETS 300 007 [20] (derived from CCITT Recommendation X.31)
(stage 3).
NOTE 1: The term ISDN packet mode services is used in a way as to include both case B (ISDN
packet mode bearer services, PMBS) and case A (PSPDN services), see
ETS 300 007 [20].
NOTE 2: No stage 2 service description existed at the time this standard was prepared.
NOTE 3: The PLL service described in ETS 300 049 [8] and supported by this standard is not
explicitly mentioned in ETS 300 007 [20].
NOTE 4: For case A services described in ETS 300 007 [20] and supported by this standard, no
stage 1 service description exists.

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ETS 300 099: August 1992
1 Scope
1.1 Implementation alternatives for ISDN packet mode services and applicability of this
specification
This specification defines a network-internal interface for the provision of ISDN packet-mode services.
The term ISDN packet mode services is defined in such a way as to include both case B (ISDN Packet
Mode Bearer Services (PMBS)), and case A (PSPDN services), see ETS 300 007 [20].
This specification shall be used if a specific implementation alternative for the provision of these services is
used in an ISDN. The implementation alternatives and the exact location of the interface are described in
the following paragraphs.
In CCITT Recommendation I.324 [6], local Connection-Related Function (CRF) and Packet-Handling
Function (PHF) are defined as being involved in the provision of packet mode bearer services (PMBS).
The local CRF includes the Exchange Termination (ET). Two basic implementation alternatives are
mentioned in subclause 3.1.2 of CCITT Recommendation I.324 and in ETS 300 007 [20]:
1) the PHF is integrated in the local CRF; and
2) the PHF is not part of the local CRF. Local CRF and PHFs are implemented with different physical
equipment and in a multi-vendor environment. In addition, the PH, although logically belonging to the
ISDN, may be physically part of the PSPDN.
In the first case, the interface between ET and PHFs can be kept internal and proprietary. In the second
case, a standardised interface between local CRF and PHFs is required. This specification defines a
manufacturer-independent interface between the local CRF and PHFs. The interface is called the Packet
Handler access point Interface (PHI).
If the second implementation alternative is chosen for the provision of packet mode services in an ISDN,
this specification shall be used for the implementation of the PHI. The existence of this specification does,
however, not preclude the choice of the first implementation alternative in an ISDN.
Considerations for the use of the PHI in private networks and interworking between private and public
networks are outside the scope of this standard. The PHI is a network-internal interface to be used in
public networks.
1.2 ISDN packet mode services supported
The full scope of services defined in ETS 300 048 [7] and ETS 300 049 [8] (Case B) and in
ETS 300 007 [20] (Cases A and B) is supported by the PHI specification, see Clause 5 for details.
Subclause 5.4 contains a table giving an overview of the services, references to the relevant sections of
the PHI specification and a conformance statement.
The PHI specification uses the term Packet Handler (PH) in both Case A and Case B services. For Case
A services, the PH assumes the role of the Access Unit (AU), see ETS 300 007 [20].
No other services are supported by the PHI specification.
1.3 Local and remote access to the PHI
The PHI denotes the interface between the PH and the CRF it i
...