ETSI ETS 300 403-2 ed.1 (1995-11)

Integrated Services Digital Network (ISDN); Digital Subscriber Signalling System No. one (DSS1) protocol; Signalling network layer for circuit-mode basic call control; Part 2: Specification and Description Language (SDL) diagrams

DE/SPS-05034-2

Digitalno omrežje z integriranimi storitvami (ISDN) - Protokol digitalne naročniške signalizacije št. 1 (DSS1) - Signalizacijska omrežna plast za krmiljenje vodovnega osnovnega klica - 2. del: Diagrami v specifikacijskem in opisnem jeziku SDL

General Information

• Status: Published
• Publication Date: 20-Nov-1995
• Technical Committee: SPS 5 - Digital access signalling
• Current Stage: 12 - Completion
• Due Date: 01-Dec-1995
• Completion Date: 21-Nov-1995
• Mandate: T-234B
• Ref Project: SIST ETS 300 403-2:1996 - Integrated Services Digital Network (ISDN); Digital Subscriber Signalling System No. one (DSS1) protocol; Signalling network layer for circuit-mode basic call control; Part 2: Specification and Description Language (SDL) diagrams

Standards Content (Sample)

SLOVENSKI STANDARD
SIST ETS 300 403-2:1996
01-GHFHPEHU-1996
'LJLWDOQRRPUHåMH]LQWHJULUDQLPLVWRULWYDPL,6'13URWRNROGLJLWDOQHQDURþQLãNH
VLJQDOL]DFLMHãW'666LJQDOL]DFLMVNDRPUHåQDSODVW]DNUPLOMHQMHYRGRYQHJD
RVQRYQHJDNOLFDGHO'LDJUDPLYVSHFLILNDFLMVNHPLQRSLVQHPMH]LNX6'/
Integrated Services Digital Network (ISDN); Digital Subscriber Signalling System No. one
(DSS1) protocol; Signalling network layer for circuit-mode basic call control; Part 2:
Specification and Description Language (SDL) diagrams
Ta slovenski standard je istoveten z: ETS 300 403-2 E1
ICS:
33.080 Digitalno omrežje z Integrated Services Digital
integriranimi storitvami Network (ISDN)
(ISDN)
35.100.30 Omrežni sloj Network layer
SIST ETS 300 403-2:1996 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

PSIST ETS 300 403-2:1996

---------------------- Page: 2 ----------------------

PSIST ETS 300 403-2:1996
EUROPEAN ETS 300 403-2
TELECOMMUNICATION November 1995
STANDARD
Source: ETSI TC-SPS Reference: DE/SPS-05034-2
ICS: 33.080, 35.100.30
ISDN, DSS1, layer 3
Key words:
Integrated Services Digital Network (ISDN);
Digital Subscriber Signalling System No. one (DSS1) protocol;
Signalling network layer for circuit-mode basic call control;
Part 2: Specification and Description Language (SDL) diagrams
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 - [e-mail]
X.400: Internet:
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 1995. All rights reserved.

---------------------- Page: 3 ----------------------

PSIST ETS 300 403-2:1996
Page 2
ETS 300 403-2: November 1995
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.

---------------------- Page: 4 ----------------------

PSIST ETS 300 403-2:1996
Page 3
ETS 300 403-2: November 1995
Contents
Foreword .5
1 Scope .7
2 Normative references.8
3 Definitions, symbols and abbreviations.8
3.1 Definitions .8
3.2 Abbreviations .8
3.3 Symbols .9
4 User side and network side call states.10
5 Network side SDL diagrams - overview .11
5.1 Call states .11
5.2 Block diagram .11
5.3 List of primitives .12
5.4 Representation method .12
6 User side SDL diagrams - overview.15
6.1 Call states .15
6.2 Block diagram .15
6.3 List of primitives .16
6.4 Representation method .16
7 Restart SDL diagrams - overview.17
7.1 States related to the restart procedure .17
7.2 Block diagram .17
7.3 List of primitives exchanged with system management .17
7.4 Representation method .18
8 Graphical SDL diagrams .18
8.1 Network side SDL diagrams .19
8.2 User side SDL diagrams.104
8.3 Restart SDL diagrams .161
Annex A (informative): Relevant differences to ETS 300 102-2 .168
A.1 Structural changes .168
A.2 Technical changes .169
History.170

---------------------- Page: 5 ----------------------

PSIST ETS 300 403-2:1996
Page 4
ETS 300 403-2: November 1995
Blank page

---------------------- Page: 6 ----------------------

PSIST ETS 300 403-2:1996
Page 5
ETS 300 403-2: November 1995
Foreword
This European Telecommunication Standard (ETS) has been produced by the Signalling Protocols and
Switching (SPS) Technical Committee of the European Telecommunications Standards Institute (ETSI).
This ETS which is based on ITU-T Recommendation Q.931 (1993) is an extended and updated version of
ETS 300 102-2 (1990) which was based on CCITT Recommendation Q.931 (1988). Annex A identifies the
relevant differences between this ETS and ETS 300 102-2.
This ETS is part 2 of a multi-part standard covering the Digital Subscriber Signalling System No. one
(DSS1) protocol specification for the Integrated Services Digital Network (ISDN) signalling network layer
for circuit-mode basic call control, as described below:
Part 1: "Protocol specification";
Part 2: "Specification and Description Language (SDL) diagrams";
Part 3: "Protocol Implementation Conformance Statement (PICS) proforma specification";
Part 4: "Test Suite Structure and Test Purposes (TSS&TP) specification for the user";
Part 5: "Abstract Test Suite (ATS) and partial Protocol Implementation eXtra Information for Testing
(PIXIT) proforma specification for the user";
Part 6: "TSS&TP specification for the network";
Part 7: "ATS and partial PIXIT proforma specification for the network".
Transposition dates
Date of adoption of this ETS: 10 November 1995
Date of latest announcement of this ETS (doa): 28 February 1996
Date of latest publication of new National Standard
or endorsement of this ETS (dop/e): 31 August 1996
Date of withdrawal of any conflicting National Standard (dow): 31 August 1996

---------------------- Page: 7 ----------------------

PSIST ETS 300 403-2:1996
Page 6
ETS 300 403-2: November 1995
Blank page

---------------------- Page: 8 ----------------------

PSIST ETS 300 403-2:1996
Page 7
ETS 300 403-2: November 1995
1 Scope
This European Telecommunication Standard (ETS) specifies the stage three of circuit-mode on-demand
basic telecommunication services for the pan-European Integrated Services Digital Network (ISDN) as
provided by European telecommunications operators at the T reference point or coincident S and T
reference point (as defined in ITU-T Recommendation I.411 [3]) by means of the Digital Subscriber
Signalling System No. one (DSS1). Stage three identifies the protocol procedures and switching functions
needed to support a telecommunication service (see CCITT Recommendation I.130 [2]).
In addition, this ETS specifies the protocol requirements at the T reference point where the service is
provided to the user via a private ISDN.
NOTE 1: Procedures at the T reference point, to support the access of a private ISDN to the
public ISDN, are not explicitly identified in this standard, however some procedures are
applicable only to the T reference point.
This ETS does not specify the additional protocol requirements where the service is provided to the user
via a telecommunication network that is not an ISDN.
This ETS is specified using the Specification and Description Language (SDL) as specified in CCITT
Recommendation Z.100 [4].
In order to describe the point-to-multipoint operation of the protocol, the concept of a "global" process
running in parallel with a number of "individual" (dynamic) processes has been introduced. This approach,
and the associated definition of internal primitives is intended to provide a coherent description of the
protocol and does not constrain implementations. The SDL diagrams in this part, and the text of clause 5
of ETS 300 403-1 [1], together provide a complete specification of the protocol within the scope of this
ETS.
A basic telecommunication service is a fundamental type of service. It forms the basis on which
supplementary services may be added.
NOTE 2: Specific requirements of individual circuit-mode basic telecommunication services are
not covered in this ETS. However, ETR 018 [5] gives guidance on the use of service
specific information elements to implement individual basic telecommunication
services.
The method of testing of this ETS is common with that for ETS 300 403-1 [1]. Further parts of this ETS
specify the method of testing and detailed application specific requirements to determine conformance
based on this ETS.
This ETS is applicable to equipment supporting circuit-mode on-demand basic telecommunication
services, to be attached at either side of a T reference point or coincident S and T reference point when
used as an access to the public ISDN.

---------------------- Page: 9 ----------------------

PSIST ETS 300 403-2:1996
Page 8
ETS 300 403-2: November 1995
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 300 403-1 (1995): "Integrated Services Digital Network (ISDN); Digital
Subscriber Signalling System No. one (DSS1) protocol; Signalling network layer
for circuit-mode basic call control; Part 1: Protocol specification [ITU-T
Recommendation Q.931 (1993), modified]".
[2] CCITT Recommendation I.130 (1988): "Method for characterization of
telecommunication services supported by an ISDN and network capabilities of
an ISDN".
[3] ITU-T Recommendation I.411 (1993): "ISDN user network interfaces - reference
configurations".
[4] CCITT Recommendation Z.100 (1988): "Specification and description language
(SDL)".
[5] ETR 018: "Integrated Services Digital Network (ISDN); Application of the Bearer
Capability (BC), High Layer Compatibility (HLC) and Low Layer Compatibility
(LLC) information elements by terminals supporting ISDN services".
3 Definitions, symbols and abbreviations
3.1 Definitions
For the purposes of this ETS, the following definitions apply in addition to those given in
ETS 300 403-1 [1]:
point-to-multipoint configuration; multipoint terminal configuration; multipoint configuration: A
terminal configuration in which there is more than one signalling entity.
point-to-multipoint data link; broadcast data link: A data link connection with the capability to support
more than two connection endpoints.
point-to-point configuration; single-point terminal configuration; single-point configuration: A
terminal configuration in which there is one signalling entity.
point-to-point data link: A data link on which a frame is directed to a single endpoint.
3.2 Abbreviations
For the purposes of this ETS, the following abbreviations apply:
CES Connection Endpoint Suffix
DSS1 Digital Subscriber Signalling System No. one
ISDN Integrated Services Digital Network
SDL Specification and Description Language

---------------------- Page: 10 ----------------------

PSIST ETS 300 403-2:1996
Page 9
ETS 300 403-2: November 1995
3.3 Symbols
For the purposes of this ETS, the following symbols apply. A full description of the symbols and their
meaning and application is given in CCITT Recommendation Z.100 [4].
State sym bol
Input sym bol (event occurrence)
Output sym bol (signal generation which will lead to an associated event
occurrence)
Save sym bol (save event until com pletion of a transition)
Task sym bol
Decision sym bol
Procedure call sym bol
Transition option sym bol (im plem entation option)
Procedure start sym bol
Procedure return sym bol
Create request sym bol (used to initiate an individual network side
transaction)
Stop sym bol (used to end an individual network side transaction)
Connection sym bol
Used m ark (an input which is local to the layer 3 entity and which
is required as a result of the representation approach adopted)

---------------------- Page: 11 ----------------------

PSIST ETS 300 403-2:1996
Page 10
ETS 300 403-2: November 1995
4 User side and network side call states
Table 1 shows which call states are applicable at the user and network sides during the various phases of
a call.
Table 1: Call states
Call phase Call state User Network
IDLE Null U0 N0
OUTGOING CALL Call initiated U1 N1
(from user) Overlap sending U2 N2
Outgoing call proceeding U3 N3
Call delivered U4 N4
INCOMING CALL Call present U6 N6
(to user) Overlap receiving U25 N25
Incoming call proceeding U9 N9
Call received U7 N7
Connect request U8 N8
ACTIVE Active U10 N10
CALL CLEARING Disconnect request (clearing by the user) U11 N11
Disconnect indication (clearing by the network) U12 N12
Release request U19 N19
Call abort - N22
CALL SUSPEND/ Suspend request U15 N15
RESUME Resume request U17 N17
RESTART Restart null REST0 REST0
PROCEDURE (note) Restart request REST1 REST1
Restart REST2 REST2
NOTE: These states relate to global call references and are applicable when the restart
procedures are used. They may exist in both user and network sides.

---------------------- Page: 12 ----------------------

PSIST ETS 300 403-2:1996
Page 11
ETS 300 403-2: November 1995
5 Network side SDL diagrams - overview
5.1 Call states
Table 2: Network side call states
Call state Name
N0 Null
N1 Call initiated
N2 Overlap sending
N3 Outgoing call proceeding
N4 Call delivered
N6 Call present
N7 Call received
N8 Connect request
N9 Incoming call proceeding
N10 Active
N11 Disconnect request
N12 Disconnect indication
N15 Suspend request
N17 Resume request
N19 Release request
N22 Call abort
N25 Overlap receiving
NOTE 1: Network side timers, and the states in which they run, are specified in clause 9 of
ETS 300 403-1 [1].
NOTE 2: Events in each state which lead to normal call establishment and clearing are marked with
the "+" symbol.
NOTE 3: The primitives which pass to and from the call control block are shown for guidance only and
are not fully specified.
NOTE 4: Internal primitives are marked by "*". These are a result of the representation method that
has been adopted.
5.2 Block diagram
(note 1)
R esource m anagem e nt
Call control
P roc ed ure
Prim itiv es
call
Block
described
Q.931 protocol control
by the SD L
diagram s
Messages to/from
User side
Data link layer
Physical la ye r
User-network
interface
User
NOTE 1: Interface not described in the SDL diagrams.
NOTE 2: Control of B-channels is described in these SDL diagrams as part of the Q.931 protocol block.
Figure 1: Block diagram for the network side

---------------------- Page: 13 ----------------------

PSIST ETS 300 403-2:1996
Page 12
ETS 300 403-2: November 1995
5.3 List of primitives
Table 3: List of primitives
From call control block To call control block
ALERTING REQUEST ALERTING INDICATION
DISCONNECT REQUEST CONNECT INDICATION
INFO REQUEST
DISCONNECT INDICATION
MORE INFO REQUEST INFO INDICATION
NOTIFY REQUEST MORE INFO INDICATION
PROCEEDING REQUEST NOTIFY INDICATION
PROGRESS REQUEST PROCEEDING INDICATION
REJECT REQUEST
PROGRESS INDICATION
RELEASE REQUEST RELEASE CONFIRM
RESUME REJECT REQUEST RELEASE INDICATION
RESUME RESPONSE RESUME INDICATION
SETUP COMPLETE REQUEST SETUP CONFIRM
SETUP REQUEST SETUP INDICATION
SETUP RESPONSE STATUS INDICATION
STATUS ENQUIRY REQUEST SUSPEND INDICATION
SUSPEND REJECT REQUEST TIMEOUT INDICATION
SUSPEND RESPONSE RESTART CONFIRM (note 2)
RESTART REQUEST (note 1)
NOTE 1: This primitive may be received from global call reference control.
NOTE 2: This primitive is sent to global call reference control.
5.4 Representation method
In order to describe the point-to-multipoint operation of the protocol, the concept of a "global" process
running in parallel with a number of "individual" (dynamic) processes in the network side has been
introduced. This approach, and the associated definition of internal primitives, is intended to provide a
coherent description of the protocol and does not constrain implementation. The textual description in
clause 5 of ETS 300 403-1 [1] is definitive.
Individual processes are used to track the responses of each terminal. The global (controlling) process
runs in parallel with the (dynamically created/destroyed) individual process.
The global and individual processes communicate by means of internal primitives. These are related to
layer 3 messages types and are defined in table 4. The internal primitives represent instantaneous
actions. Thus, there is no possibility of errors caused by the crossover of primitives.
The global process maintains a list of recorded Connection Endpoint Suffix (CES) values to enable it to
manage the individual processes. In this representation the global process also keeps a record of the
state of the individual process associated with each responding terminal. Additionally a "preselected" CES
is recorded when one terminal responds with a CONNECT message and this becomes the "selected"
CES when the terminal is awarded the call.
This solution is compatible with point-to-point configurations. In this case the global process never creates
any individual processes, and the timers defined in ETS 300 403-1 [1] for the relevant states are handled
by the global process, including timer T322 which may run in any state except the Null state. Also, ever
since a transition to the Null state occurs, the stopping of this timer (if running) should be regarded as an
implicit statement, as it is not shown in order not to extend the SDL representation.

---------------------- Page: 14 ----------------------

PSIST ETS 300 403-2:1996
Page 13
ETS 300 403-2: November 1995
In a point-to-multipoint configuration, individual processes may exist in the following states:
N0 Null (processes are created in this state);
N7 Call received;
N8 Connect request;
N9 Incoming call proceeding;
N19 Release request;
N25 Overlap receiving.
Two sets of SDL diagrams are required for these states to show the global and individual processes.
The global process handles all communications with call control. Messages from individuals terminals are
sent to the individual process for that terminal if one exists (i.e. if the CES is recognized). Messages with
an unrecognized CES are passed to the global process. Messages with the selected CES are also sent to
the global process.
In a point-to-multipoint configuration, the handling of the timers defined in ETS 300 403-1 [1] has been
done according to the following principles:
a) timers T301 and T310 only run in the global process when an incoming call is being offered;
b) timers T304, T308 and T322 only run in the individual processes when an incoming call is being
offered. The stopping of timer T322 (if running) when an individual process is destroyed should be
regarded as an implicit statement as it is not shown in order not to extend the SDL representation;
c) in the other phases of a call, the timers associated with each state, as well as timer T322 which
may run in any state except the Null state, are all handled by the global process. Once again, the
stopping of this timer (if running) should be regarded as an implicit statement because it extends
the SDL representation.
Table 4: Network side layer 3 internal primitives
Primitive name From To Meaning
INT. ALERTING REQ Global Individual When global process receives ALERTING it starts
INT. CONNECT REQ an individual process and sends
INT. CALL PROC REQ INT. ALERTING REQ to it
INT. SETUP ACK REQ (etc.)
INT. ALERTING IND Individual Global Sent on receipt of ALERTING
INT. CONNECT IND (etc.)
INT. CALL PROC IND
END PROCESS Global Individual Sent when the global process terminates an
individual process
INT. RELEASE REQ Global Individual Instructs individual process to release terminal
(e.g. for releasing non-selected terminals)
INT. RELEASE IND Individual Global Informs global process that a terminal has begun
to release
INT. INFO REQ Global Individual Sent on receipt of INFO REQ
INT. INFO IND Individual Global Sent on receipt of INFO
INT. STAT. ENQ. REQ Global Individual Sent on receipt of STATUS ENQUIRY REQ
INT. PROGRESS IND Individual Global Sent on receipt of PROGRESS
INT. REL. COMP. IND Individual Global Sent to indicate that the individual process has
been cleared
NOTE: The global process should not release the call reference until all individual processes have
completed clearing.
Figure 2 (an arrow diagram) shows an example of this representation method.

---------------------- Page: 15 ----------------------

PSIST ETS 300 403-2:1996
Page 14
ETS 300 403-2: November 1995
Terminal 1 Terminal 2 Terminal 3 Network
0
SETU P (BR OAD C AST) SETU P R EQ
6 T3 03
ALER TIN G ALERTIN G IN D
o
IN T. ALER TIN G R EQ
T312
7
ALER TIN G 7i
o
IN T. ALER TIN G R EQ
ALE R TIN G 7i
o
IN T. ALER TIN G R EQ
CONNECT 7i INT. CONNECT IND CONNECT IND
8i 8
C ONNEC T ACK REQ
EN D PR O C ESS
CO NNECT ACK
x
RELEASE IN T. R EL EASE R EQ
19i T308
R ELEASE INT. R ELEASE R EQ T312 expires
(no state change)
10
19i T30 8
IN T. R EL. C OM P. IN D
RELEASE CO M PLETE
R ELEAS E C O M PLE TE x IN T. R EL. C O M P. IN D
x
N O TE:    o = creation of state m achine, x = deletion of state m achine; num bers indicate states of the state m achines show n.
Figure 2: M ultipoint call establishm ent (and clearing of non-selected term inals)

---------------------- Page: 16 ----------------------

PSIST ETS 300 403-2:1996
Page 15
ETS 300 403-2: November 1995
6 User side SDL diagrams - overview
6.1 Call states
Table 5: User side call states
Call state Name
U0 Null
U1 Call initiated
U2 Overlap sending
U3 Outgoing call proceeding
U4 Call delivered
U6 Call present
U7 Call received
U8 Connect request
U9 Incoming call proceeding
U10 Active
U11 Disconnect request
U12 Disconnect indication
U15 Suspend request
U17 Resume request
U19 Release request
U25 Overlap receiving
NOTE 1: User side timers, and the states in which they run, are specified in clause 9 of
ETS 300 403-1 [1].
NOTE 2: Events in each state which lead to normal call establishment/clearing are shown by the "+"
symbol.
NOTE 3: Primitives passed to and from the call control (user application) block are shown for
guidance only and are not fully specified.
6.2 Block diagram
(note 1)
Resource m anagem ent
Call control
Procedure
Prim itives
call
Block
describ ed
Q.931 protocol control
by the SDL
diagram s
Messages to/from
User side
D ata link layer
Physical layer
User-network
interface
Network
NOTE 1: Interface not described in the SDL diagrams.
NOTE 2: Control of B-channels is described in these SDL diagrams as part of the Q.931 protocol block.
Figure 3: Block diagram for the user side

---------------------- Page: 17 ----------------------

PSIST ETS 300 403-2:1996
Page 16
ETS 300 403-2: November 1995
6.3 List of primitives
Table 6: List of primitives
From call control block To call control block
ALERTING REQUEST ALERTING INDICATION
DISCONNECT REQUEST DISCONNECT INDICATION
INFO REQUEST
INFO INDICATION
MORE INFO REQUEST MORE INFO INDICATION
NOTIFY REQUEST NOTIFY INDICATION
PROCEEDING REQUEST PROCEEDING INDICATION
PROGRESS REQUEST PROGRESS INDICATION
REJECT REQUEST
RELEASE CONFIRM
RELEASE REQUEST RELEASE INDICATION
RESUME REQUEST (note 1) RESUME CONFIRM
SETUP REQUEST SETUP COMPLETE INDICATION
SETUP RESPONSE SETUP CONFIRM
STATUS ENQUIRY REQUEST SETUP INDICATION
SUSPEND REQUEST (note 1) STATUS INDICATION
RESTART REQUEST (note 2) SUSPEND CONFIRM
RESTART CONFIRM (note 3)
NOTE 1: These primitives are not defined for a primary rate access, i.e. the use of the call
rearrangement procedure is restricted to basic access.
NOTE 2: This primitive may be received from global call reference control.
NOTE 3: This primitive is sent to global call reference control.
6.4 Representation method
The representation method of user side SDL diagrams has not followed the concept of a global process
running in parallel with a number of individual processes, because from a signalling point of view only one
call is handled by the global process at each time. Therefore, the global process never creates any
individual processes, and only one set of SDL diagrams is required to represent the user side call states.
As a consequence, the timers associated with each state, as well as timer T322 which may run in any
state except the Null state, are all handled by the global process. Also, as mentioned for the network side,
the stopping of this timer (if running) should be regarded as an implicit statement because it extends the
SDL representation.

---------------------- Page: 18 ----------------------

PSIST ETS 300 403-2:1996
Page 17
ETS 300 403-2: November 1995
7 Restart SDL diagrams - overview
7.1 States related to the restart procedure
Table 7: States related to the restart procedure
Call state Name
REST0 Restart null
REST1 Restart request
REST2 Restart
NOTE 1: Timers related to the restart procedure, and the states in which they run, are specified in
clause 9 of ETS 300 403-1 [1].
NOTE 2: The primitives which pass to and from the system management block (see table 8) and the
protocol control block (see tables 3 and 6) are shown for guidance only and are not fully
specified.
7.2 Block diagram
(note)
Resource m anagement
Call control
P rocedure
call
Block
described
Q.931 protocol control
Global call reference control
by the SD L
diagram s
D ata link layer
Physical layer
User/
Network
NOTE: Interface not described in the SDL diagrams.
Figure 4: Block diagram for the restart procedure
7.3 List of primitives exchanged with system management
Table 8: List of primitives
From system management block To system management block
MANAGEMENT RESTART REQUEST TIMEOUT MANAGEMENT INDICATION
STATUS MANAGEMENT INDICATION
MANAGEMENT RESTART CONFIRM
NOTE: Primitives related to the restart procedure which may be sent or received to/from
protocol control block are already indicated in tables 3 and 6.

---------------------- Page: 19 ----------------------

PSIST ETS 300 403-2:1996
Page 18
ETS 300 403-2: November 1995
7.4 Representation method
The representation method of the restart SDL diagrams follows the concept of a single finite state
machine running in the global call reference control block (see figure 4), in order to describe the restart
procedure and the associated states defined in ETS 300 403-1 [1] subclause 5.5 and subclause 2.4,
respectively.
Whenever a collision of restart procedures initiated by either side of the interface may occur, it shall be
handled by a separate finite state machine approach.
NOTE: Due to the complexity of the representation, this approach is not presented.
In this subset of diagrams, reference is made to some flags in order to make the SDL representation more
transparent. The flags have the following meaning:
a) REST RESP: either by initiative of the management entity or because a RESTART message has
been received, the global call reference control entity has sent primitives RESTART REQUEST to
each protocol entity associated with an active call reference, and is waiting for a reply from them.
The flag is set when they all have responded;
...

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Integrated Services Digital Network (ISDN); Digital Subscriber Signalling System No. one (DSS1) protocol; Signalling network layer for circuit-mode basic call control; Part 2: Specification and Description Language (SDL) diagrams35.100.30Omrežni slojNetwork layer33.080Digitalno omrežje z integriranimi storitvami (ISDN)Integrated Services Digital Network (ISDN)ICS:Ta slovenski standard je istoveten z:ETS 300 403-2 Edition 1PSIST ETS 300 403-2:1996en01-oktober-1996PSIST ETS 300 403-2:1996SLOVENSKI
STANDARD



PSIST ETS 300 403-2:1996



EUROPEANETS 300 403-2TELECOMMUNICATIONNovember 1995STANDARDSource: ETSI TC-SPSReference: DE/SPS-05034-2ICS:33.080, 35.100.30Key words:ISDN, DSS1, layer 3Integrated Services Digital Network (ISDN);Digital Subscriber Signalling System No. one (DSS1) protocol;Signalling network layer for circuit-mode basic call control;Part 2: Specification and Description Language (SDL) diagramsETSIEuropean Telecommunications Standards InstituteETSI SecretariatPostal address: F-06921 Sophia Antipolis CEDEX - FRANCEOffice address: 650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCEX.400: c=fr, a=atlas, p=etsi, s=secretariat - Internet: [e-mail].: [phone] - Fax: [phone]Copyright Notification: No part may be reproduced except as authorized by written permission. The copyright and theforegoing restriction extend to reproduction in all media.© European Telecommunications Standards Institute 1995. All rights reserved.PSIST ETS 300 403-2:1996*



Page 2ETS 300 403-2: November 1995Whilst 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.PSIST ETS 300 403-2:1996



Page 3ETS 300 403-2: November 1995ContentsForeword.51Scope.72Normative references.83Definitions, symbols and abbreviations.83.1Definitions.83.2Abbreviations.83.3Symbols.94User side and network side call states.105Network side SDL diagrams - overview.115.1Call states.115.2Block diagram.115.3List of primitives.125.4Representation method.126User side SDL diagrams - overview.156.1Call states.156.2Block diagram.156.3List of primitives.166.4Representation method.167Restart SDL diagrams - overview.177.1States related to the restart procedure.177.2Block diagram.177.3List of primitives exchanged with system management.177.4Representation method.188Graphical SDL diagrams.188.1Network side SDL diagrams.198.2User side SDL diagrams.1048.3Restart SDL diagrams.161Annex A (informative):Relevant differences to ETS 300 102-2.168A.1Structural changes.168A.2Technical changes.169History.170PSIST ETS 300 403-2:1996



Page 4ETS 300 403-2: November 1995Blank pagePSIST ETS 300 403-2:1996



Page 5ETS 300 403-2: November 1995ForewordThis European Telecommunication Standard (ETS) has been produced by the Signalling Protocols andSwitching (SPS) Technical Committee of the European Telecommunications Standards Institute (ETSI).This ETS which is based on ITU-T Recommendation Q.931 (1993) is an extended and updated version ofETS 300 102-2 (1990) which was based on CCITT Recommendation Q.931 (1988). Annex A identifies therelevant differences between this ETS and ETS 300 102-2.This ETS is part 2 of a multi-part standard covering the Digital Subscriber Signalling System No. one(DSS1) protocol specification for the Integrated Services Digital Network (ISDN) signalling network layerfor circuit-mode basic call control, as described below:Part 1:"Protocol specification";Part 2:"Specification and Description Language (SDL) diagrams";Part 3:"Protocol Implementation Conformance Statement (PICS) proforma specification";Part 4:"Test Suite Structure and Test Purposes (TSS&TP) specification for the user";Part 5:"Abstract Test Suite (ATS) and partial Protocol Implementation eXtra Information for Testing(PIXIT) proforma specification for the user";Part 6:"TSS&TP specification for the network";Part 7:"ATS and partial PIXIT proforma specification for the network".Transposition datesDate of adoption of this ETS:10 November 1995Date of latest announcement of this ETS (doa):28 February 1996Date of latest publication of new National Standardor endorsement of this ETS (dop/e):31 August 1996Date of withdrawal of any conflicting National Standard (dow):31 August 1996PSIST ETS 300 403-2:1996



Page 6ETS 300 403-2: November 1995Blank pagePSIST ETS 300 403-2:1996



Page 7ETS 300 403-2: November 19951ScopeThis European Telecommunication Standard (ETS) specifies the stage three of circuit-mode on-demandbasic telecommunication services for the pan-European Integrated Services Digital Network (ISDN) asprovided by European telecommunications operators at the T reference point or coincident S and Treference point (as defined in ITU-T Recommendation I.411 [3]) by means of the Digital SubscriberSignalling System No. one (DSS1). Stage three identifies the protocol procedures and switching functionsneeded to support a telecommunication service (see CCITT Recommendation I.130 [2]).In addition, this ETS specifies the protocol requirements at the T reference point where the service isprovided to the user via a private ISDN.NOTE 1:Procedures at the T reference point, to support the access of a private ISDN to thepublic ISDN, are not explicitly identified in this standard, however some procedures areapplicable only to the T reference point.This ETS does not specify the additional protocol requirements where the service is provided to the uservia a telecommunication network that is not an ISDN.This ETS is specified using the Specification and Description Language (SDL) as specified in CCITTRecommendation Z.100 [4].In order to describe the point-to-multipoint operation of the protocol, the concept of a "global" processrunning in parallel with a number of "individual" (dynamic) processes has been introduced. This approach,and the associated definition of internal primitives is intended to provide a coherent description of theprotocol and does not constrain implementations. The SDL diagrams in this part, and the text of clause 5of ETS 300 403-1 [1], together provide a complete specification of the protocol within the scope of thisETS.A basic telecommunication service is a fundamental type of service. It forms the basis on whichsupplementary services may be added.NOTE 2:Specific requirements of individual circuit-mode basic telecommunication services arenot covered in this ETS. However, ETR 018 [5] gives guidance on the use of servicespecific information elements to implement individual basic telecommunicationservices.The method of testing of this ETS is common with that for ETS 300 403-1 [1]. Further parts of this ETSspecify the method of testing and detailed application specific requirements to determine conformancebased on this ETS.This ETS is applicable to equipment supporting circuit-mode on-demand basic telecommunicationservices, to be attached at either side of a T reference point or coincident S and T reference point whenused as an access to the public ISDN.PSIST ETS 300 403-2:1996



Page 8ETS 300 403-2: November 19952Normative referencesThis ETS incorporates by dated and undated reference, provisions from other publications. Thesenormative references are cited at the appropriate places in the text and the publications are listedhereafter. For dated references, subsequent amendments to or revisions of any of these publicationsapply to this ETS only when incorporated in it by amendment or revision. For undated references the latestedition of the publication referred to applies.[1]ETS 300 403-1 (1995): "Integrated Services Digital Network (ISDN); DigitalSubscriber Signalling System No. one (DSS1) protocol; Signalling network layerfor circuit-mode basic call control; Part 1: Protocol specification [ITU-TRecommendation Q.931 (1993), modified]".[2]CCITT Recommendation I.130 (1988): "Method for characterization oftelecommunication services supported by an ISDN and network capabilities ofan ISDN".[3]ITU-T Recommendation I.411 (1993): "ISDN user network interfaces - referenceconfigurations".[4]CCITT Recommendation Z.100 (1988): "Specification and description language(SDL)".[5]ETR 018: "Integrated Services Digital Network (ISDN); Application of the BearerCapability (BC), High Layer Compatibility (HLC) and Low Layer Compatibility(LLC) information elements by terminals supporting ISDN services".3Definitions, symbols and abbreviations3.1DefinitionsFor the purposes of this ETS, the following definitions apply in addition to those given inETS 300 403-1 [1]:point-to-multipoint configuration; multipoint terminal configuration; multipoint configuration: Aterminal configuration in which there is more than one signalling entity.point-to-multipoint data link; broadcast data link: A data link connection with the capability to supportmore than two connection endpoints.point-to-point configuration; single-point terminal configuration; single-point configuration: Aterminal configuration in which there is one signalling entity.point-to-point data link: A data link on which a frame is directed to a single endpoint.3.2AbbreviationsFor the purposes of this ETS, the following abbreviations apply:CESConnection Endpoint SuffixDSS1Digital Subscriber Signalling System No. oneISDNIntegrated Services Digital NetworkSDLSpecification and Description LanguagePSIST ETS 300 403-2:1996



Page 9ETS 300 403-2: November 19953.3SymbolsFor the purposes of this ETS, the following symbols apply. A full description of the symbols and theirmeaning and application is given in CCITT Recommendation Z.100 [4].State symbolInput symbol (event occurrence)Output symbol (signal generation which will lead to an associated eventoccurrence)Save symbol (save event until completion of a transition)Task symbolDecision symbolProcedure call symbolTransition option symbol (implementation option)Procedure start symbolProcedure return symbolCreate request symbol (used to initiate an individual network sidetransaction)Stop symbol (used to end an individual network side transaction)Connection symbolUsed mark (an input which is local to the layer 3 entity and whichis required as a result of the representation approach adopted)PSIST ETS 300 403-2:1996



Page 10ETS 300 403-2: November 19954User side and network side call statesTable 1 shows which call states are applicable at the user and network sides during the various phases ofa call.Table 1: Call statesCall phaseCall stateUserNetworkIDLENullU0N0OUTGOING CALL(from user)Call initiatedOverlap sendingOutgoing call proceedingCall deliveredU1U2U3U4N1N2N3N4INCOMING CALL(to user)Call presentOverlap receivingIncoming call proceedingCall receivedConnect requestU6U25U9U7U8N6N25N9N7N8ACTIVEActiveU10N10CALL CLEARINGDisconnect request (clearing by the user)Disconnect indication (clearing by the network)Release requestCall abortU11U12U19-N11N12N19N22CALL SUSPEND/RESUMESuspend requestResume requestU15U17N15N17RESTARTPROCEDURE (note)Restart nullRestart requestRestartREST0REST1REST2REST0REST1REST2NOTE:These states relate to global call references and are applicable when the restartprocedures are used. They may exist in both user and network sides.PSIST ETS 300 403-2:1996



Page 11ETS 300 403-2: November 19955Network side SDL diagrams - overview5.1Call statesTable 2: Network side call statesCall stateNameN0NullN1Call initiatedN2Overlap sendingN3Outgoing call proceedingN4Call deliveredN6Call presentN7Call receivedN8Connect requestN9Incoming call proceedingN10ActiveN11Disconnect requestN12Disconnect indicationN15Suspend requestN17Resume requestN19Release requestN22Call abortN25Overlap receivingNOTE 1:Network side timers, and the states in which they run, are specified in clause 9 ofETS 300 403-1 [1].NOTE 2:Events in each state which lead to normal call establishment and clearing are marked withthe "+" symbol.NOTE 3:The primitives which pass to and from the call control block are shown for guidance only andare not fully specified.NOTE 4:Internal primitives are marked by "*". These are a result of the representation method thathas been adopted.5.2Block diagramCall controlResource managementProcedurecallQ.931 protocol controlMessages to/fromUser sideData link layerPhysical layerUser-networkinterfaceUserBlockdescribedby the SDLdiagramsPrimitives(note 1)NOTE 1:Interface not described in the SDL diagrams.NOTE 2:Control of B-channels is described in these SDL diagrams as part of the Q.931 protocol block.Figure 1: Block diagram for the network sidePSIST ETS 300 403-2:1996



Page 12ETS 300 403-2: November 19955.3List of primitivesTable 3: List of primitivesFrom call control blockTo call control blockALERTING REQUESTDISCONNECT REQUESTINFO REQUESTMORE INFO REQUESTNOTIFY REQUESTPROCEEDING REQUESTPROGRESS REQUESTREJECT REQUESTRELEASE REQUESTRESUME REJECT REQUESTRESUME RESPONSESETUP COMPLETE REQUESTSETUP REQUESTSETUP RESPONSESTATUS ENQUIRY REQUESTSUSPEND REJECT REQUESTSUSPEND RESPONSERESTART REQUEST (note 1)ALERTING INDICATIONCONNECT INDICATIONDISCONNECT INDICATIONINFO INDICATIONMORE INFO INDICATIONNOTIFY INDICATIONPROCEEDING INDICATIONPROGRESS INDICATIONRELEASE CONFIRMRELEASE INDICATIONRESUME INDICATIONSETUP CONFIRMSETUP INDICATIONSTATUS INDICATIONSUSPEND INDICATIONTIMEOUT INDICATIONRESTART CONFIRM (note 2)NOTE 1:This primitive may be received from global call reference control.NOTE 2:This primitive is sent to global call reference control.5.4Representation methodIn order to describe the point-to-multipoint operation of the protocol, the concept of a "global" processrunning in parallel with a number of "individual" (dynamic) processes in the network side has beenintroduced. This approach, and the associated definition of internal primitives, is intended to provide acoherent description of the protocol and does not constrain implementation. The textual description inclause 5 of ETS 300 403-1 [1] is definitive.Individual processes are used to track the responses of each terminal. The global (controlling) processruns in parallel with the (dynamically created/destroyed) individual process.The global and individual processes communicate by means of internal primitives. These are related tolayer 3 messages types and are defined in table 4. The internal primitives represent instantaneousactions. Thus, there is no possibility of errors caused by the crossover of primitives.The global process maintains a list of recorded Connection Endpoint Suffix (CES) values to enable it tomanage the individual processes. In this representation the global process also keeps a record of thestate of the individual process associated with each responding terminal. Additionally a "preselected" CESis recorded when one terminal responds with a CONNECT message and this becomes the "selected"CES when the terminal is awarded the call.This solution is compatible with point-to-point configurations. In this case the global process never createsany individual processes, and the timers defined in ETS 300 403-1 [1] for the relevant states are handledby the global process, including timer T322 which may run in any state except the Null state. Also, eversince a transition to the Null state occurs, the stopping of this timer (if running) should be regarded as animplicit statement, as it is not shown in order not to extend the SDL representation.PSIST ETS 300 403-2:1996



Page 13ETS 300 403-2: November 1995In a point-to-multipoint configuration, individual processes may exist in the following states:N0Null (processes are created in this state);N7Call received;N8Connect request;N9Incoming call proceeding;N19Release request;N25Overlap receiving.Two sets of SDL diagrams are required for these states to show the global and individual processes.The global process handles all communications with call control. Messages from individuals terminals aresent to the individual process for that terminal if one exists (i.e. if the CES is recognized). Messages withan unrecognized CES are passed to the global process. Messages with the selected CES are also sent tothe global process.In a point-to-multipoint configuration, the handling of the timers defined in ETS 300 403-1 [1] has beendone according to the following principles:a)timers T301 and T310 only run in the global process when an incoming call is being offered;b)timers T304, T308 and T322 only run in the individual processes when an incoming call is beingoffered. The stopping of timer T322 (if running) when an individual process is destroyed should beregarded as an implicit statement as it is not shown in order not to extend the SDL representation;c)in the other phases of a call, the timers associated with each state, as well as timer T322 whichmay run in any state except the Null state, are all handled by the global process. Once again, thestopping of this timer (if running) should be regarded as an implicit statement because it extendsthe SDL representation.Table 4: Network side layer 3 internal primitivesPrimitive nameFromToMeaningINT. ALERTING REQINT. CONNECT REQINT. CALL PROC REQINT. SETUP ACK REQGlobalIndividualWhen global process receives ALERTING it startsan individual process and sendsINT. ALERTING REQ to it(etc.)INT. ALERTING INDINT. CONNECT INDINT. CALL PROC INDIndividualGlobalSent on receipt of ALERTING(etc.)END PROCESSGlobalIndividualSent when the global process terminates anindividual processINT. RELEASE REQGlobalIndividualInstructs individual process to release terminal(e.g. for releasing non-selected terminals)INT. RELEASE INDIndividualGlobalInforms global process that a terminal has begunto releaseINT. INFO REQGlobalIndividualSent on receipt of INFO REQINT. INFO INDIndividualGlobalSent on receipt of INFOINT. STAT. ENQ. REQGlobalIndividualSent on receipt of STATUS ENQUIRY REQINT. PROGRESS INDIndividualGlobalSent on receipt of PROGRESSINT. REL. COMP. INDIndividualGlobalSent to indicate that the individual process hasbeen clearedNOTE:The global process should not release the call reference until all individual processes havecompleted clearing.Figure 2 (an arrow diagram) shows an example of this representation method.PSIST ETS 300 403-2:1996



Page 14ETS 300 403-2: November 1995Terminal 1Terminal 2Terminal 3NetworkSETUP (BROADCAST)0SETUP REQALERTINGT303ALERTING INDINT. ALERTING REQ7iALERTINGALERTINGINT. ALERTING REQ7iINT. ALERTING REQ7iINT. CONNECT INDCONNECTEND PROCESS8i RELEASEINT. RELEASE REQRELEASERELEASE COMPLETEINT. RELEASE REQ19iT3086T312CONNECT IND10T312 expires(no state change)19iT308INT. REL. COMP. INDRELEASE COMPLETEINT. REL. COMP. INDCONNECT ACKCONNECT ACK REQ7Figure 2: Multipoint call establishment (and clearing of non-selected terminals)8NOTE:
o = creation of state machine, x = deletion of state machine; numbers indicate states of the state machines shown.xxxoooPSIST ETS 300 403-2:1996



Page 15ETS 300 403-2: November 19956User side SDL diagrams - overview6.1Call statesTable 5: User side call statesCall stateNameU0NullU1Call initiatedU2Overlap sendingU3Outgoing call proceedingU4Call deliveredU6Call presentU7Call receivedU8Connect requestU9Incoming call proceedingU10ActiveU11Disconnect requestU12Disconnect indicationU15Suspend requestU17Resume requestU19Release requestU25Overlap receivingNOTE 1:User side timers, and the states in which they run, are specified in clause 9 ofETS 300 403-1 [1].NOTE 2:Events in each state which lead to normal call establishment/clearing are shown by the "+"symbol.NOTE 3:Primitives passed to and from the call control (user application) block are shown forguidance only and are not fully specified.6.2Block diagramCall controlResource managementProcedurecallQ.931 protocol controlMessages to/fromUser sideData link layerPhysical layerUser-networkinterfaceNetworkBlockdescribedby the SDLdiagramsPrimitives(note 1)NOTE 1:Interface not described in the SDL diagrams.NOTE 2:Control of B-channels is described in these SDL diagrams as part of the Q.931 protocol block.Figure 3: Block diagram for the user sidePSIST ETS 300 403-2:1996



Page 16ETS 300 403-2: November 19956.3List of primitivesTable 6: List of primitivesFrom call control blockTo call control blockALERTING REQUESTDISCONNECT REQUESTINFO REQUESTMORE INFO REQUESTNOTIFY REQUESTPROCEEDING REQUESTPROGRESS REQUESTREJECT REQUESTRELEASE REQUESTRESUME REQUEST (note 1)SETUP REQUESTSETUP RESPONSESTATUS ENQUIRY REQUESTSUSPEND REQUEST (note 1)RESTART REQUEST (note 2)ALERTING INDICATIONDISCONNECT INDICATIONINFO INDICATIONMORE INFO INDICATIONNOTIFY INDICATIONPROCEEDING INDICATIONPROGRESS INDICATIONRELEASE CONFIRMRELEASE INDICATIONRESUME CONFIRMSETUP COMPLETE INDICATIONSETUP CONFIRMSETUP INDICATIONSTATUS INDICATIONSUSPEND CONFIRMRESTART CONFIRM (note 3)NOTE 1:These primitives are not defined for a primary rate access, i.e. the use of the callrearrangement procedure is restricted to basic access.NOTE 2:This primitive may be received from global call reference control.NOTE 3:This primitive is sent to global call reference control.6.4Representation methodThe representation method of user side SDL diagrams has not followed the concept of a global processrunning in parallel with a number of individual processes, because from a signalling point of view only onecall is handled by the global process at each time. Therefore, the global process never creates anyindividual processes, and only one set of SDL diagrams is required to represent the user side call states.As a consequence, the timers associated with each state, as well as timer T322 which may run in anystate except the Null state, are all handled by the global process. Also, as mentioned for the network side,the stopping of this timer (if running) should be regarded as an implicit statement because it extends theSDL representation.PSIST ETS 300 403-2:1996



Page 17ETS 300 403-2: November 19957Restart SDL diagrams - overview7.1States related to the restart procedureTable 7: States related to the restart procedureCall stateNameREST0Restart nullREST1Restart requestREST2RestartNOTE 1:Timers related to the restart procedure, and the states in which they run, are specified inclause 9 of ETS 300 403-1 [1].NOTE 2:The primitives which pass to and from the system management block (see table 8) and theprotocol control block (see tables 3 and 6) are shown for guidance only and are not fullyspecified.7.2Block diagramCall controlResource managementProcedurecallQ.931 protocol controlData link layerPhysical layerUser/NetworkBlockdescribedby the SDLdiagramsGlobal call reference control(note)NOTE:Interface not described in the SDL diagrams.Figure 4: Block diagram for the restart procedure7.3List of primitives exchanged with system managementTable 8: List of primitivesFrom system management blockTo system management blockMANAGEMENT RESTART REQUESTTIMEOUT MANAGEMENT INDICATIONSTATUS MANAGEMENT INDICATIONMANAGEMENT RESTART CONFIRMNOTE:Primitives related to the restart procedure which may be sent or received to/fromprotocol control block are already indicated in tables 3 and 6.PSIST ETS 300 403-2:1996



Page 18ETS 300 403-2: November 19957.4Representation methodThe representation method of the restart SDL diagrams follows the concept of a single finite statemachine running in the global call reference control block (see figure 4), in order to describe the restartprocedure and the associated states defined in ETS 300 403-1 [1] subclause 5.5 and subclause 2.4,respectively.Whenever a collision of restart procedures initiated by either side of the interface may occur, it shall behandled by a separate finite state machine approach.NOTE:Due to the complexity of the representation, this approach is not presented.In this subset of diagrams, reference is made to some flags in order to make the SDL representation moretransparent. The flags have the following meaning:a)REST RESP: either by initiative of the management entity or because a RESTART message hasbeen received, the global call reference control entity has sent primitives RESTART REQUEST toeach protocol entity associated with an active call reference, and is waiting for a reply from them.The flag is set when they all have responded;b)REST ACK: by initiative of the management entity, the global call reference entity has sent aRESTART message to its peer entity (in the network side or in the user side), and is waiting for aRESTART ACKNOWLEDGE. The flag is set when this message is received;c)T317 EXPIRED: either by initiative of the management entity or because a RESTART message hasbeen received, the global call reference control entity has sent primitives RESTART REQUEST toeach protocol entity associated with an active call reference, and is waiting for a reply from them.The flag is set if they have not responded in due time, and timer T317 has expired.8Graphical SDL diagramsThis clause is separated into three subclauses:-network side SDL diagrams (figure 5, sheets 1 to 85);-user side SDL diagrams (figure 6, sheets 1 to 57);-restart SDL diagrams (figure 7, sheets 1 to 7).All references in the following diagrams are to ETS 300 403-1 [1].PSIST ETS 300 403-2:1996



Page 19ETS 300 403-2: November 19958.1Network side SDL diagramsProcess NETWORK_SIDE1(85)NETWORK SIDE SDL DIAGRAMSNOTE 1. THE EXPIRY OF TIMER T307 IS NOT SHOWN IN THESE SDLs AS IT RUNS IN THE CALL CONTROL BLOCK.0NULLRELEASE5.8.3.2 (b)ESTABLISHCRRELEASECOMPLETE(CAUSE #81)RELEASECR0RESUMEACCESS?ESTABLISHCRRELEASECOMPLETE(CAUSE #81)RELEASECR0ESTABLISHCRRELEASE(CAUSE #81)STARTT30819ESTABLISHCRRESUMEINDICATION175.65.6.45.6.5+SETUP5.1.15.1.2+ESTABLISHCRCHNLSELECTIONSUCCESS?RELEASECOMPLETE(CAUSE #34 OR #44)RELEASECR0SETUPINDICATION1PRABRANYFigure 5 (sheet 1 of 85): Network side SDL diagramPSIST ETS 300 403-2:1996



Page 20ETS 300 403-2: November 1995Process NETWORK_SIDE2(85)NETWORK SIDE SDL DIAGRAMSNOTE 1. ANY OTHER MESSAGE EXCEPT STATUS ENQUIRY, SEE PAGES DEALING WITH DIAGRAMS RELATED TO ANY GLOBAL OR INDIVIDUAL STATE.NOTE 2. CAUSE #101 IS RETURNED IF A STATUS MESSAGE IS RECEIVED, WHILE CAUSE #81 APPLIES FOR OTHER MESSAGES.0NULLRELEASECOMPLETE5.8.3.2 (c)0OTHERMESSAGEESTABLISHCRRELEASECOMPLETE(CAUSE #81 OR #101)NOTE 2RELEASECR0ESTABLISHCRRELEASE(CAUSE #81 OR #101)NOTE 2STARTT308195.8.3.2 (a),NOTE 1STATUS5.8.11CS=0?0NYFigure 5 (sheet 2 of 85): Network side SDL diagramPSIST ETS 300 403-2:1996



Page 21ETS 300 403-2: November 1995Process NETWORK_SIDE3(85)NETWORK SIDE SDL DIAGRAMSNOTE 1. THIS INPUT MAY BE RECEIVED FROM A TERMINAL COMPLETING CLEARING IN A POINT-TO-MULTIPOINT CONFIGURATION.
THE CALL RE
...