Path: utzoo!attcan!utgpu!watmath!att!bellcore!rutgers!apple!brutus.cs.uiuc.edu!wuarchive!texbell!vector!telecom-gateway From: chancer@houxa.att.com (Robert C Chancer) Newsgroups: comp.dcom.telecom Subject: Re: Service Interactions Between CFU and CCBS (Busy Retry) Message-ID: Date: 19 Sep 89 19:59:17 GMT Sender: news@vector.Dallas.TX.US Organization: AT&T Bell Laboratories Lines: 39 Approved: telecom-request@vector.dallas.tx.us X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@vector.dallas.tx.us X-TELECOM-Digest: volume 9, issue 390, message 2 of 7 > The original question was: > > >I have a Special Report For Service Interactions by S. J. Chin (BNR Canada) > >of CCITT working party XI/5 (1987). > > > >The title of the report is "Specification technique for stage 2 > >supplementary service interactions". > >....... The particular example that was given involved > >the CFU (Call Forwarding Unconditional) and CCBS (Completion of Call to > >Busy Subscriber which is just a retry service) services. The example goes > >like this "... A user activating CFU, when being scanned/monitored for > >CCBS recall, will cause the scanning/monitoring to be withdrawn or > >abandoned." > >My question is why withdraw the scanning ? Why not bar the user who is > >being scanned from activating CFU ? There are a few more examples from Having worked on Stage 2 descriptions in CCITT and have some understanding of the implementations of CCBS being described I may be able to shed some light on the subject. Call Completion to Busy Subscriber may be totally implemented in the originators switch. It would only poll the other switch to see if the Called party is busy. The destination switch would have no knowledge of the timers for CCBS or possibly even that CCBS was invoked. So, if a user at the destination switch wanted to invoke a service, such as CFU, it would allow it. If CCBS is implemented by the destination switch, via a message from the originating switch to implement, then this info could be used to disallow CFU. One ot the things being strived for in CCIT is a consistent service view to the customer, you cannot have the service be different depending on the implementation, so CFU takes precedence. Bob Chancer houxa!chancer