Subject: Re: Service Interactions Between CFU and CCBS (Busy Retry)
Organization: AT&T Bell Laboratories
> 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CCBS recall, will cause the scanning/monitoring to be withdrawn or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
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From: 90784000 <sandy47@ucsco.ucsc.edu>
Subject: Re: Telephony in Belgium
Date: 20 Sep 89 09:00:50 GMT
Reply-To: sandy47@ucsco.ucsc.edu
Organization: University of California, Santa Cruz
I was stationed in The Netherlands (Maastricht) in the US Air Force during
1966-1969 as part of a radio relay maintenance team. We had two microwave
sites in Germany, two in The Netherlands, and two in Belgium, in addition to
a maintenance site at Roclenge sur Geer, Belgium. We constantly used the
telephone system to contact all six sites from Belgium and I learned inter-
national dialing early in life. It was less than 15 minutes driving between
the Maastricht site (located in a Dutch PTT tower) to the maintenance site in
Belgium, but was an international call.
What made it particularly bad was that our site was located on the dividing
line between the Flemish (Dutch) and Walloon (French) speaking sections of
Belgium. Telephone maintenance was all but impossible and winter conditions at our sites in the Ardenne Mountains made it worse. We had all of the sites
linked by HF radio as a backup, but often we would drive to Maastricht across
the border to use the microwave communications channels connecting the sites
to make reliable contact!
Our customers were all military as part of the Allied Forces Central Europe
(AFCENT) network and we essentially duplicated the existing HF/VHF radio
links and PTT/RTT networks. As I was leaving Europe in 1969, satellite
networks were taking over much of the communications requirements.
Belgium had to be one of the more interesting countries in Europe at that
time, since they were just instituting vehicle drivers licenses in 1969
(as I recall) and most drivers were grandfathered into the system. The others
had to either take a written exam _or_ a road test! Belgium also had one of
the highest accident rates in Europe then.
Thanks for the reminder!
------------------------------
From: 90784000 <sandy47@ucsco.ucsc.edu>
Subject: Re: Central Office Answering Machine
Date: 20 Sep 89 09:42:46 GMT
Reply-To: Larry McElhiney <sandy47@ucsco.ucsc.edu>
Organization: University of California, Santa Cruz
In article <telecom-v09i0379m04@vector.dallas.tx.us> john@zygot.ati.com (John
Higdon) writes:
>X-TELECOM-Digest: volume 9, issue 379, message 4 of 4