Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!wuarchive!texbell!vector!telecom-gateway From: munnari!batserver.cs.uq.oz.au!anthony@uunet.uu.net (Anthony Lee) Newsgroups: comp.dcom.telecom Subject: Re: Service interactions between CFU and CCBS (Busy Retry) Message-ID: Date: 18 Sep 89 00:25:45 GMT Sender: news@vector.Dallas.TX.US Reply-To: anthony%batserver.cs.uq.OZ@uunet.uu.net Organization: Computer Science Department, The University of Queensland, Lines: 84 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 384, message 1 of 5 I have two responses to my question on CCBS and CFU. The following is a summary of replies to my question. 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CCBS recall, will cause the scanning/monitoring to be withdrawn or abandoned."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 ============================= One reply was actually from S. J. Chin: I noticed your question about CFU and CCBS, and an article by Mr. S. J. Chin. I forwarded a copy of your message to Mr. Chin, who happens to work (somewhere!!) in this building. His reply, in part, is as follows: I'm no longer working on feature interactions. To answer the specific questions below: - why CFU overrides CCBS: the 2 features are incompatible, ie cannot be activated at the same time, so one has to give way, and CFU having precedence over CCBS makes for simpler interactions and/or more 'rational' operation from the users perspective (eg the U in CFU stands for Unconditional, ie the user would expect to be able to activate the feature irrespective of any outstanding CCBS, etc). ..... swee-joo ... Daniel Zlatin ========================== My comment: Why does CFU having precedence over CCBS makes for simpler interactions ? ========================== The second reply: Someone else responsed that the reason why a subscriber wanted to invoke CFU is because he might not want to be disturbed at that particular number. >My question is why withdraw the scanning ? Why not bar the user who is >being scanned from activating CFU ? A decision based on the user's perspective. If I'm setting CFU, it's because I don't want to be disturbed. Unconditionally (hence the 'U'). .... J. Deters - jad@dayton.DHDSC.MN.ORG john@jaded.DHDSC.MN.ORG ========================== My comment: There are however other reasons why a subscriber might want to invoke CFU. For example he might want to move to a new location and do not want to miss important calls. If the subscriber did not want to be disturbed then why not set up call blocking instead ? The setting of CFU could be that the subscriber do not want to be distributed but still wants to record important calls and so have all future calls forwarded to and answering machine. If that's the case then why not have the CCBS scanning transferred to the forwarded number ? This kind of question can also arise in a PBX as well, so are there any PBX manufacturers out there who care to comment ? cheers Anthony Anthony Lee (Humble PhD student) (alias Doctor(Time Lord)) ACSnet: anthony@batserver.cs.uq.oz TEL:(+617) 3712651 Internet: anthony@batserver.cs.uq.oz.au (+617) 3774139 (w) SNAIL: 243 Carmody Rd, St Lucia, Queensland 4067, Australia