Subject: [Megaco] Effect of subtract on H.248.26 BCAS calls

From: "Kamitses, Jerry" <[email-masked]>
Date: Thu, 25 Aug 2005 14:06:30 -0400

A question has arisen during interop testing regarding the effect of 
subtracting a termination from a context while there is an active 
CAS call on that termination. For example, if 
(1) an outgoing CAS call is setup and answered on a physical termination 
    using a sequence of Modify commands on the NULL context, 
(2) that termination is subsequently added to a context, 
(3) subsequently that termination is subtracted from this context, 
then what effect, if any, does the subtract have on the CAS call?

Based on our understanding of the relevant standards the CAS call 
would be unaffected by the subtract. Is this correct? 

Also based on our understanding of the relevant standards the CAS call 
could be effected by the subtract happens to occur while one of the 
BCAS signals used to establish the call is pending. Is this correct? 

If possible please provide a specific reference to the standard(s) 
(existing or proposed) and relevant page/paragraphs that clearly 
apply to this question. 

_______________________________________________
Megaco mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/megaco

---

From: "Kevin Boyle" <[email-masked]>
Date: Thu, 25 Aug 2005 14:29:05 -0400

If the CAS termination is not in context with a bearer of some nature,
then you'll have no voicepath.  So saying Subtract has no effect is not
really true...

Remember that the SG Descriptor reverts to its default or provisioned
value upon Subtract (H.248.1 7.2.3).  Generally, I would think the
default SG Descriptor would contain bcas/idle.  So the call would be
torn down upon Subtract.

Kevin 

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf
Of Kamitses, Jerry
Sent: Thursday, August 25, 2005 2:07 PM
To: [email-masked]
Subject: [Megaco] Effect of subtract on H.248.26 BCAS calls

A question has arisen during interop testing regarding the effect of
subtracting a termination from a context while there is an active CAS
call on that termination. For example, if
(1) an outgoing CAS call is setup and answered on a physical termination

    using a sequence of Modify commands on the NULL context,
(2) that termination is subsequently added to a context,
(3) subsequently that termination is subtracted from this context, then
what effect, if any, does the subtract have on the CAS call?

Based on our understanding of the relevant standards the CAS call would
be unaffected by the subtract. Is this correct? 

Also based on our understanding of the relevant standards the CAS call
could be effected by the subtract happens to occur while one of the BCAS
signals used to establish the call is pending. Is this correct? 

If possible please provide a specific reference to the standard(s)
(existing or proposed) and relevant page/paragraphs that clearly apply
to this question.