1、 AMERICAN NATIONAL STANDARD FOR TELECOMMUNICATIONS ATIS-1000613.1991(R2012) Integrated Services Digital Network (ISDN) Call Waiting Supplementary Service ATIS is the leading technical planning and standards development organization committed to the rapid development of global, market-driven standard
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11、y calling or writing the American National Standards Institute. Notice of Disclaimer 5430 Grosvenor Lane; Bethesda, MD 20814-2122. This standard was processed and approved for submittal to ANSI by Accredited Standards Committee Tl - Telecommunications. Committee approval of the standard does not imp
12、ly that all committee members voted for its approval. At the time it approved this standard, Accredited Standards Committee Tl had the following members: lvor N. Knight, Chairman Arthur K. Reilly, Vice-Chairman O.J. Gusella, Jr., Secretary Organization Represented Name of Representative EXCHANGE CAR
13、RIERS Ameritech Services, Inc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lawrence A. Young Robert Koren (Aft.) Bell Atlantic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . John W. Seazhoftr Roger Nucho (Alt.) Bellcore . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Gary G. Schl
15、anger Ralph E. Jensen (AA.) BellSouth Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Leonard Strickland, Jr. William J. McNamara, Ill (Alt.) Centel Corporation . . . . . . . . . . . . . . . . . . . .
16、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bruce Becker Cincinnati Bell Telephone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . William P. Keidel T. C. Grimes (Alt.) Contel
17、Corporation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Russell G. Dewitt Stephen P. Welsh (Alt.) Exchange Carriers Standards Association . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Jo
18、seph Mendoza Gregory L. Theus (Alt.) GTE Telephone Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Gregory L. Theus Richard L. Cochran (Alt.) l) This standard is under development. Contact the secretariat for more information.
19、. . . III Organization Represented Name of Representative National Telephone Cooperative Association . . . . . . . . . . . . . . . . . . . . . . . . . . . . Joseph M. Flanigan NYNEX Service Company . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
20、. . . . . . . Bencilla Jenkins Leo Katz (Alt.) Pacific Bell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fred Doell Tom Garcia (Alt.) Puerto Rico Telephone Company . . . . . . . . .
21、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Segundo Ruiz Southern New England Telephone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . H. D. Mulla J. K. Vij (Alt.) Southwestern Bell Corporation . . . . . . . . . . . . . . . .
22、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Joseph Mendoza C. C. Bailey (Alt.) United States Telephone Association . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Paul K. Hart Thomas Gajeski (Alt.) US WEST . . . . . . . . . . . . . . . . . .
23、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . James L. Eitel James Dahl (Alt.) United Telecommunications, Inc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Robert P. M
24、cCabe Harold L. Fuller (Alt.) INTEREXCHANGE CARRIERS ATt$;Farn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ameritech Services, Inc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25、 . . . . . . . . . . . . . . . . . . . . . . . James E. Bendel Wayne Heinmiller (Alt.) AT - maximum number of information chan- nels available to each ISDN number or group of numbers per bearer service. 4.2.2 Normal procedures 4.2.2.1 Activation/deactivation Activation and deactivation can be provid
26、ed by subscription, or as a service provider option, can be provided to some or all users without subscription. 4.2.2.2 Invocation and operation Figure 1 shows an overall SDL diagram for the invocation and operation of the Call Waiting service. Table 1 - Subscription options for Call Waiting (per nu
27、mber and bearer service) , 1 Subscription options Values Call Waiting assigned No Yes Calling user receives notification their call is waiting Called user receives in-band notification No Yes Yes No Table 2 - Subscription options for Call Waiting (per ISDN number and bearer service, all ISDN numbers
28、 and bearer service, or subsets of ISDN numbers and bearer service) Subscription option Values Maximum number 1 to N, where the of calls that can be maximum value of “N” is waiting a service provider option 4.2.2.2.1 Invocation When an incoming call from User C arrives at the access of Subscriber B
29、and encounters the channels busy condition without a network- determined user busy condition, then the Call Waiting service shall be invoked and the call shall be offered to Subscriber B with an indi- cation that the channels busy condition exists. 4.2.2.2.2 Indication If a response is received from
30、 a terminal at Subscriber Bs access, within the normal basic call period, that Subscriber B is being informed about the incoming call, then User C shall be given an indication that the called subscriber is being informed of the incoming call if Subscriber B subscribes to the “Calling user receives n
31、otification their call is waiting” option. The optional timer T2 may be started when Sub- scriber B is informed of the incoming call. As 3 ANSI T1.613-1991 a service provider option and a network pro- vider option, a call waiting indication may be included in the alerting indication provided to User
32、 C. Delivery of call waiting notification to User C is dependent on all intermediate net- works supporting the option to deliver the no- tification. 4.2.2.2.3 Clearing an existing call and then accepting a waiting call If one of the terminals on Subscriber Bs access terminates a call with User A bef
33、ore the expiry of the optional No Answer Timer T2, then the User A call shall be released in the normal manner. Any compatible terminal on Subscriber Bs access shall then be able to accept the waiting call from User C. If one of the terminals on Subscriber Bs access terminates a held call, any compa
34、tible terminal on Subscriber Bs access shall be able to accept the waiting call, subject to the channel reservation restrictions of the Call Hold service. 4.2.2.2.4 Holding an existing call and then accepting a waiting call If one of the terminals on Subscriber Bs access holds an active call with Us
35、er A before the expiry of the optional No Answer Timer T2, the call shall be held in the normal manner. Any compatible terminal on Subscriber Bs access shall then be able to accept the waiting call from User C, subject to the channel reserva- tion restrictions of Call Hold. 4.2.2.2.5 Accepting a wai
36、ting call if User A terminates If User A terminates a call with one of the terminals on Subscriber Bs access before the expiration of the optional No Answer Timer T2, the call shall be released in the normal manner. Any compatible terminal on Subscriber Bs access shall then be able to accept the wai
37、ting call from User C. If the call that was released was a held call, any compatible terminal on Subscriber Bs access shall be able to accept the waiting call, subject to the channel reservation restrictions of the Call Hold service. 4.2.3 Exceptional procedures 4.2.3.1 Activation/deactivation/regis
38、tra- tion None identified. 4 4.2.3.2 Invocation and operation 4.2.3.2.1 Incoming call from User C ig- nored by Subscriber B If the optional No Answer Timer T2 expires without any acceptance from Subscriber B of the incoming call, then the network shall inform Subscriber B that the call is no longer
39、waiting and also inform User C that the call cannot be connected. Normal release procedures apply and an appropriate indication shall be given to User C. 4.2.3.2.2 Incoming call from User C re- jected by Subscriber B A rejection of the waiting call by one of the terminals on Subscriber Bs access sha
40、ll not stop the optional No Answer Timer T2, as another terminal may subsequently accept the waiting call within the remainder of the speci- fied period. Such a rejection shall, however, cancel any indication provided to that rejecting terminal. If rejections of a waiting call have been re- ceived f
41、rom all those terminals that responded with an alerting indication before the expiry of the No Answer Timer T2, then the network shall inform User C that this call cannot be connected. Normal release applies to the call attempt from User C, with the call being cleared indicating user rejection. Subs
42、criber B shall be notified that the call is no longer waiting. 4.2.3.2.3 Release by User C within the specified period If User C informs the network, before the expi- ration of the optional No Answer Timer T2, that he or she wishes to release this call attempt to Subscriber B, then the network shall
43、 inform Subscriber B of this situation and complete the release of the call attempt from User C. 4.2.3.2.4 No positive response from ter- minals at Subscriber Bs interface If no positive response that Subscriber B is being informed of the waiting call is received from any terminal at Subscriber Bs a
44、ccess during the normal call period (Response Timer Tl), then the network shall release the call attempt from User C and give User C the reason for the release. ANSI T1.613-1991 C.I 25 Setup from C LA3 Call Waiting Null Basic Call or Other Possible Supplementary Services Offer Call to B with I I Cal
45、l Waiting Null “No Available Info. Channels” indication Other Possible Supplementary Services “No Channel” . . . NOTE - A is User A; B is User B; C is User C. Figure 1 - Overall SDL diagram of Call Waiting 5 ANSI Tl.613-1991 I Wait for User Response I I Req from B (hold A) Hold (A - B by B) I I Disc
46、onnect Timer 1 (terminate call from A) (psyse . . . . a . . I See Basic . , i See Basic i Call Process i Call Process * -. . . *a Disconnect . . . i No Channel (A - W ; Reservation 5 Notify A , “remote hold” Wait for User I Response L t t Wait for User Response Figure 1 (continued) 6 ANSI T1.613-199
47、1 I I Answer Disconnect (Cause) _. . . J . . . . I See Basic . .: See Basic : Call Process *, . . i Call Process . . . . No Timer Figure 1 (continued) ANSI Tl X13-1 991 User Responded (Waiting C-B) No answer timer “No B-Channel Figure 1 (continued) 8 ANSI T1.613-1991 7 User Responded (Waiting C-6) ,
48、 J F 4 User Responded (Waiting C-B) Yes Disconnect (C-W Reject C-B Cause: User Rejection Reject C-B,Cause: No Answer From User (user alerted) I Null Figure 1 (concluded) 9 ANSI T1.613-1991 4.2.3.2.5 No resources available If one of the terminals on Subscriber Bs ac- cess accepts a call and network r
49、esources do not exist to complete the call (i.e., no infor- mation channels are available), the network shall indicate an error to that terminal. The network shall not clear the call but shall wait for another indication of acceptance from another terminal on Subscriber Bs access until User C clears the call or the optional No Answer Timer T2 expires. 4.3 Interworking considerations 4.3.1 ISDN-served user: Non-ISDN calling user No interworking situations exist beyond those required for communications with respect to the basic call. If an ISDN Subscriber B receives a c
