[cisco-voip] Missed DISCONNECT

[Andre Beck]

Re,

On Tue, Nov 14, 2006 at 03:18:41PM +0300, Fedorov, Konstantin wrote:
> 
> How I understand you main concern about
> Why after receiving disconnect my router doesn't send release message ,
> correct ??

Well, the main concern is that calls to the outside that hit a busy
destination don't get a busy signal, but display "Ruf weiterführen"
(dunno what it is in en_US, maybe "continue call") for a long time,
more than a minute after the DISCONNECT was received. The caller has
neither visual nor audible feedback of what happened to the call. As
this could also mean a slow response by the network until an actual
ALERTING is received (with mobile providers I've seen this can take
more then 10s as well), they are unsure when to hang up.

> But on the whole, call completes successfully, correct ??

No, as it hits a busy destination anyway. Calls that don't hit a busy
destination work as expected.
 
> I think that you must not worry about this, this is called two-way
> disconnect, both parties must hang-up.

When the local user finally hangs up, the usual signaling takes place
until the callref is freed (RELEASE_COMP). The problem is that no
sign of the fact that the destination is busy ever reaches the local
caller, because the DISCONNECT isn't acted upon in any way (it should
either switch the inband tone announced by the network towards the user
so they know they can hang up, or instantly release and play a busy
tone locally - it should not completely ignore the message).

I'll see whether I can upgrade to a newer IOS in the maintenance
window we have there next week in order to add a new CCM cluster
member. It's just that I dislike making too many changes at once.
I have a really bad feeling about upgrading a central voice gateway
from 12.3(11)T2 to 12.4, as I *know* there were newly introduced
issues with alerting (stomped into this puddle myself).

-- 
                  The _S_anta _C_laus _O_peration
  or "how to turn a complete illusion into a neverending money source"

-> Andre Beck    +++ ABP-RIPE +++    IBH Prof. Dr. Horn GmbH, Dresden <-