1、ITU-T RECMN*Q=957 93 = 48b259L 05138703 OT7 W INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Q.957 (03/93) DIGITAL SUBSCRIBER SIGNALLING SYSTEM No. 1 STAGE 3 DESCRIPTION FOR SUPPLEMENTARY SERVICES USING DSS 1 STAGE 3 DESCRIPTION FOR ADDITIONAL INFORMATION
2、 TRANSFER SUPPLEMENTARY SERVICES USING DSS 1 CLAUSE i - USER-TO-USER SIGNALLING (UUS) ITU-T Recommendation (2.957 (Previously “CCIT Recommendation”) ITU-T RECMN*Q-957 93 = 4862571 0588704 T33 FOREWORD The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the International
3、Telecom- munication Union. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Conference (WTSC), which meets every four y
4、ears, established the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. ITU-T Recommendation Q.957, clause 1, was prepared by the ITU-T Study Group XI (1988-1993) and was approved by the WTSC (Helsinki, March 1-12, 1993). NOTES 1 As a consequen
5、ce of a reform process within the International Telecommunication Union (ITU), the CCITT ceased to exist as of 28 February 1993. In its place, the ITU Telecommunication Standardization Sector (ITU-T) was created as of 1 March 1993. Similarly, in this reform process, the CCIR and the IFRB have been r
6、eplaced by the Radiocommunication Sector. In order not to delay publication of this Recommendation, no change has been made in the text to references containing the acronyms “CCITT, CCIR or IFRB” or their associated entities such as Plenary Assembly, Secretariat, etc. Future editions of this Recomme
7、ndation will contain the proper terminology related to the new ITU structure. 2 telecommunication administration and a recognized operating agency. In this Recommendation, the expression “Administration” is used for conciseness to indicate both a O ITU 1994 All rights reserved. No part of this publi
8、cation may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. 1 ITU-T RECMN*Q.957 93 W Y8b2591 0588705 97T = CONTENTS User-to-User Signalling (UUS) 1.2 Description 1.3 Operational requirem
9、ents 1.4 Coding Requirements . 1.1 Definition 1.5 Signalling requirements 1.6 Interaction with other supplementary services . 1.7 Interactions with other networks . 1.9 Parameter values (timers) . 1.8 Signalling flow 1.10 Dynamic description (SDLs) References . Recommendation Q.957 (03/93) Page 1 1
10、1 2 2 9 17 19 19 20 20 20 i ITU-T RECMN*Q-957 93 m 4862593 0588706 806 m Recommendation Q.957 STAGE 3 DESCRIPTION FOR ADDITIONAL INFORMATION TRANSFER SUPPLEMENTARY SERVICES USING DSS 1 (Helsinki, 1993) 1 User-to-User Signalling (UUS) 1.1 Definition The user-user signalling (UUS) supplementary servic
11、e allows an ISDN user to sendreceive a limited amount of information to/from another ISDN user over the signalling channel in association with a call to the other ISDN user. 1.2 Description 1.2.1 General description The UUS supplementary services provide a means of communication between two users by
12、 using as a basis the layer 3 protocol defined in Y4.93 1 i. User-user signalling is used to exchange information between two users to provide the services described in the Stage 1 Service Description. The exchange of user-user signalling is limited by flow control procedures provided by the network
13、 or the user. The exchange of user-to-user information is not a network acknowledged service. Any acknowledgement procedure shall be controlled at a higher layer between users. Three UUS services associated with circuit-switched calls that may be provided by the network to users are: i) service I -
14、User-user information exchanged during the setup and clearing phases of a call, by transporting User-user information element within 4.93 1 i call control messages; ii) service 2 - User-user information exchanged from the senders point of view during call establishment, between the ALERTING and CONN
15、ECT messages, within USER INFORMATION messages; and iii) service 3 - User-user information exchanged while a call is in the Active state, within USER INFORMATION messages. Ali three services may be used separately or in any combination in association with a single call. As an option, at call Set-up,
16、 users may be able to specify that the requested user-to-user signalling service(s) is (are) required for the call, i.e. the call should not be completed if user-to-user information cannot be passed. 1.2.2 Specific terminology The user is the DSS 1 protocol entity at the user side of the user-networ
17、k interface. The network is the DSS 1 protocol entity at the network side of the user-network interface. The called user is the user who is offered an incoming call at the terminating interface. The calling user is the user who initiates an outgoing call at the originating interface. The served user
18、 is the user requesting the User-to-User (UUS) supplementary service. The invoke component is defined in Recommendation 4.932 2. Recommendation Q.957 (03/93) 1 ITU-T RECMN*Q=957 93 48b259L 0588707 742 H 1.2.3 Qualifications on the applicability to telecommunications services See Recommendation 1.257
19、.1 3. 1.2.4 State definitions The states associated with basic call control according to Recommendation 4.93 1 i are applicable. 1.3 Operational requirements 1.3.1 Provisiodwithdrawal UUS services 1 and 2 must be subscribed to by the calling user. UUS service 3 must be subscribed to by the served us
20、er. Whether these component services are offered to the user as separate supplementary or in any particular combination is a service provider option. 1.3.2 Requirements on the originating network side The basic call control procedures according to 5. UQ.93 1 i are applicable. 1.3.3 Requirements in t
21、he network Not applicable to DSS 1, 1.3.4 Requirements on the terminating network side The basic call control procedures according to 5.2/Q.931 i are applicable. 1.3.5 Assumptions made about the terminai Terminal equipment using UUS service 1 is expected to be able to generate and accept the User-us
22、er information element (see 4.5.30/Q.931 i) as described in 1.5.2.1 below. In the case of explicit activation, it is also expected to support the codings and procedures in 1.5.2.1. Terminal equipment using UUS service 2 is expected to be able to generate and/or accept USER INFORMATION messages conta
23、ining the User-user information element (see 4.5.30/Q.931 i) as described in 1.5.2.2.3 below. It is also expected to support the codings and procedures in 1.5.2.2. Terminal equipment using UUS service 3 is expected to be able to generate andor accept USER INFORMATION messages containing the User-use
24、r information element (see 4.5.30/Q.931 i) as described in 1.5.2.3.4 below. It is also expected to support the codings and procedures in 1.5.2.3 below. In the case that congestion control is used, it is also expected to support the CONGESTION CONTROL message and the Congestion Level Information Elem
25、ent (see 4.5.1414.93 1 i), and to comply with the procedures of 1.5.2.3.5 below. 1.4 Coding requirements 1.4.1 Messages The following messages are applicable to service activation for services 1,2 and 3: SETUP, SETUP ACKNOWLEDGE, CALL PROCEEDING, PROGRESS, ALERTING, CONNECT, DISCONNECT, RELEASE, REL
26、EASE COMPLETE. The FACILITY message is also applicable to the activation of service 3. The following messages are applicable to the operation of service 1: SETUP, ALERTING, CONNECT, DISCONNECT, RELEASE, RELEASE COMPLETE. The following message is applicable to the operation of services 2 and 3: USER
27、INFORMATION. Where the congestion control procedures are used, the following message is applicable to service 3: CONGESTION CONTROL. 2 Recommendation Q.957 (03D3) ITU-T RECMN*Q.957 93 4862593 0588708 b89 W The following are message contents for UUS services. Message Type: ALERTING Reference Directio
28、n I Length Information element Protocol discriminator Call reference Message type = ALERTING Facility User-user 4.214.93 1 4.3Q.93 1 4.41Q.93 1 8.2.3lQ.932 4.5.30lQ.931 Both Both Both Both Both 1 2-* 1 19 2-131 M M M O (Note i) O (Note 2) NOTES 1 Not included otherwise for UUS service 1. 2 3 Always
29、included for activation of service 2. Always included in user-network direction for explicit activation of service 1. May be included for service 1 (explicit or implicit activation) where no contention is allowed. Other mandatory and optional information elements per Recommendation Q.931. Message Ty
30、pe: CALL PROCEEDING Reference Direction I Type Length Information element Protocol discriminator Call reference Message type = CALL PROCEEDING Facility NOTES 4.214.93 1 4.3lQ.931 4.4fQ.93 1 Both Both Both Both M M M O (Note 1) 1 2-* 1 19 8.2.314.932 1 Included only for rejection of explicit service
31、1, service 2 or service 3 request. 2 Other mandatory and optional information elements per Recommendation Q.93 1. Message Type: CONGESTION CONTROL Information element Reference Direction Type Length Protocol discriminator Call reference Message type = CONGESTION CONTROL Congestion level Cause 4.2lQ.
32、931 4.314.931 4.4Q.931 8.2.314.931 4.5.24Q.931 N+U N+U N+U N+U N+U M M M M M 1 2-* 1 1 4-32 NOTE - Other optional information elements per Recommendation 4.931. Recommendation Q.957 (03/93) - 3 ITU-T RECMN*Q.957 93 iI8b2.591 0588709 515 I Information element Reference Direction Type Length Both M Bo
33、th M Both M Both O (Note i) 1 2-* 1 19 Message Type: CONNECT Information element Reference Direction I Length Protocol discriminator Call reference Message type = CONNECT Facility User-user 4.214.931 4.3lQ.931 4.414.93 1 8.2.314.932 4.5.3lQ.931 Both Both Both Both Both M M M O (Note i) O (Note 2) 1
34、2-* 1 19 2-131 NOTES 1 Always included for explicit service 1 activation when contention is allowed for the call, and for service 3 activation during call establishment. May also be included for explicit service 1 activation when contention is not allowed for the call, if not present in the ALERTING
35、 message. Not otherwise included for UUS service. 2 May be included for service 1 (explicit or implicit activation). Not included otherwise. 3 Other mandatory and optional information elements Der Recommendation 0.93 I. Message Type: DISCONNECT Information element Direction Reference Length Protocol
36、 discriminator Call reference Message type = DISCONNECT Facility User-user 4.21Q.93 1 4.314.931 4.44.93 1 8.2.314.932 4.5.3014.931 Both Both Both Both Both M M M O (Note 2) O (Note 1) 1 2-* 1 19 2-131 NOTES 1 May be included for UUS service 1 where DISCONNECT is the first clearing message. Not inclu
37、ded otherwise. 2 May be included to indicate explicit servicelacceptance or service 1,2 or 3 rejection. 3 Other mandatory and optional information elements per Recommendation 4.931. Message Type: FACILITY 4.214.93 1 4.3lQ.931 8.114.932 8.2.3lQ.932 Protocol discriminator Call reference Message type =
38、 FACILITY Facility I I NOTES 1 Included for UUS service 3 activation or deactivation during a call. 2 Other mandatory and optional information elements per Recommendation 4.932. 4 Recommendation 4.957 (03193) ITU-T RECMNmQ.957 93 D 4862571 0588730 237 D Type M M M O (Note 1) Message Type: PROGRESS L
39、ength 1 2-* 1 2-131 Reference Direction Both Both Both U-+N Direction Type M M M O (Note 1) Length Information element Protocol discriminator Call reference Message type = PROGRESS Facility User-user 4.214.93 1 4.31Q.931 4.414.93 1 8.2.314.932 4.5.3014.93 1 Both Both Both N+U N+U M M M O (Note 1) O
40、(Note 2) 1 2-* 1 19 2-131 NOTES 1 Included only for rejection of explicit service 1, service 2 or service 3 request. 2 Included (e.g. in conjunction with in-band tones or announcements) when the PROGRESS message is sent by the network to indicate that the call has been cleared before reaching the ac
41、tive state by the remote user, and a User-user information element was present in the clearing message. 3 Other mandatory and optional information elements per Recommendation Q.93 1. Message Type: RELEASE Information element I Reference Direction 4.2lQ.931 4.3lQ.931 4.414.93 1 4.5.30lQ.931 Both Both
42、 Both Both Protocol discriminator Call reference Message type = RELEASE User-user NOTES 1 May be included for UUS service i where RELEASE is the first clearing message. Not included otherwise. 2 Other mandatory and optional information elements per Recommendation Q.931. Message Type: RELEASE COMPLET
43、E Information element Reference Length Protocol discriminator Call reference Message type = RELEASE COMPLETE User-user 4.2lQ.93 i 4.3lQ.931 4.41Q.93 1 4.5.3OlQ.93 1 1 2-* 1 2-131 NOTES 1 May be included for UUS service 1 where a RELEASE COMPLETE message is sent by the user to reject an incoming SETU
44、P message. Not included otherwise. 2 Other mandatory and optional information elements per Recommendation Q.93 1. Recommendation Q.957 (03/93) 5 ITU-T Message Type: SETUP 8.2.31Q.932 Both RECMN*Q.957 93 W g86259L 05887LL 173 O (Note 1) Both O (Note i) Information element Reference Length Direction B
45、oth Both Both Both Both Type M M M O (Note i) O (Note 2) Protocol discriminator Cali reference Message type = SETUP Facility User-user 4.21Q.931 4.31Q.93 1 4.414.93 i 8.2.3lQ.932 4.5.30lQ.931 1 2-* 1 19 2-131 NOTES 1 Always included for explicit service 1 activation, service 2 activation, and servic
46、e 3 activation during call establishment. 2 Always included for implicit service 1 activation; the length must be at least three octets. May also be included for service i when explicit activation is used. Not included otherwise. 3 Other mandatory and optional information elements per Recommendation
47、 Q.93 1. Message Type: SETUP ACKNOWLEDGE Information element Reference Direction I Length Protocol discriminator Cali reference Message type = SETUP ACKNOWLEDGE Facility 4.214.93 1 4.3lQ.93 1 4.41Q.931 Both Both Both M M M 1 2-* 1 19 NOTES 1 Included only for rejection of explicit service 1, service
48、 2 or service 3 request. 2 Other mandatory and optional information elements per Recommendation Q.93 1. Message Type: USER INFORMATION Information element Reference Direction Length Protocol discriminator 4.214.931 4.3lQ.931 4.41Q.931 Both Both Both Both M M M O 1 2-* 1 1 14 2-131 Cali reference Mes
49、sage type = USER INFORMATION More data Facility User-user 4.5.1914.93 1 8.3.214.932 4.5.301Q.93 1 NOTES 1 Included in conjunction with interaction with the Conference Call Add-on supplementary service if USER INFORMATION messages are senureceived tolfrom a specific conferee. 2 Other mandatory and optional information elements per Recommendation Q.93 1. 6 Recommendation Q.957 (03/93) ITU-T RECMNxQ.957 93 m 4862573 0588732 OOT m 1.4.2 Codesets All information elements are in codeset O. 1.4.3 Information elements The Facility information element is a
