Subject: [Sip] Question on CALL HOLD...

From: Idnani Ajaykumar-AIDNANI1 <[email-masked]>
Date: Thu, 11 Sep 2003 13:43:22 -0500

Hi,
 
I was going through call flow for CALL HOLD in the services draft http://www.ietf.org/internet-drafts/draft-ietf-sipping-service-examples-05.txt <http://www.ietf.org/internet-drafts/draft-ietf-sipping-service-examples-05.txt> . and I had a simple question.
 
Assume a scenario where a UA is on HOLD, so it has received the INVITE (hold) and has stopped sending the audio (media) to the peer. Now assume that the party on HOLD receives a new INVITE from another peer which it wants to take. A normal way of doing this would be to put the existing call on hold and accept the new call. But in this case the existing call is already on HOLD, so what should the UA do.
 
-         Should it still send the INVITE (hold), but this will reverse the direction of the audio (a=sendonly instead of a=recvonly).
-         Or Should it accept the new call w/o doing anything with the existing call since it is already on HOLD. In this case when the peer takes the existing call OFF HOLD, then that would interfere with the audio on the new call.
-         Should it go with the second option, but in addition when the peer takes the call OFF HOLD, it should respond back with a 200 OK that contains (a=sendonly) in the SDP body, thus putting the peer on HOLD.
 
Appreciate your help on this.
 
- Ajay

---

From: Ranjit Avasarala <[email-masked]>
Date: Fri, 12 Sep 2003 11:11:54 +0530

Hi Ajay
 
When UA is on hold, then that particular call session is on hold. So now
when u receive a new call, then first place ur UA must be capabale of
receiving multiple calls (i.e call waiting enabled). Else the second
call will be dropped.
 
So assuming call wait is enabled, u can accept the new call as the prev
call is already on hold. So this functionality depends on sip stack
implementation. 
 
Ranjit
-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of Idnani
Ajaykumar-AIDNANI1
Sent: Friday, September 12, 2003 12:13 AM
To: [email-masked]
Subject: [Sip] Question on CALL HOLD...

Hi,
 
I was going through call flow for CALL HOLD in the services draft
http://www.ietf.org/internet-drafts/draft-ietf-sipping-service-examples-
05.txt. and I had a simple question.
 
Assume a scenario where a UA is on HOLD, so it has received the INVITE
(hold) and has stopped sending the audio (media) to the peer. Now assume
that the party on HOLD receives a new INVITE from another peer which it
wants to take. A normal way of doing this would be to put the existing
call on hold and accept the new call. But in this case the existing call
is already on HOLD, so what should the UA do.
 
-         Should it still send the INVITE (hold), but this will reverse
the direction of the audio (a=sendonly instead of a=recvonly).
-         Or Should it accept the new call w/o doing anything with the
existing call since it is already on HOLD. In this case when the peer
takes the existing call OFF HOLD, then that would interfere with the
audio on the new call.
-         Should it go with the second option, but in addition when the
peer takes the call OFF HOLD, it should respond back with a 200 OK that
contains (a=sendonly) in the SDP body, thus putting the peer on HOLD.

- Ajay