Niall Murray
2010-08-10 08:20:01 UTC
Hello All,
My question is probably quite simple as I am new to SIP but I have a
http://tools.ietf.org/html/rfc3725.
In all of the examples in this document, the controller initiates the
session. My query relates to the scenario whereby if a device acting as a
controller *receives *an invite. If this called controlling device was
aware of a number of local devices it wanted to use in the session I imagine
that it could either parse the initial invite SDP, and send the updated or
new SDP (with relevant SDP parts) to each of the respective devices e.g. m
=audio is sent to speaker, whereas m=video is sent to display device. Or an
alternative approach would be just to forward the initial invite SDP to all
the devices and parse and edit the SDP "answer" back to the calling device.
Audio / Video Device Controller Speaker Display
Device
| |My question is probably quite simple as I am new to SIP but I have a
http://tools.ietf.org/html/rfc3725.
In all of the examples in this document, the controller initiates the
session. My query relates to the scenario whereby if a device acting as a
controller *receives *an invite. If this called controlling device was
aware of a number of local devices it wanted to use in the session I imagine
that it could either parse the initial invite SDP, and send the updated or
new SDP (with relevant SDP parts) to each of the respective devices e.g. m
=audio is sent to speaker, whereas m=video is sent to display device. Or an
alternative approach would be just to forward the initial invite SDP to all
the devices and parse and edit the SDP "answer" back to the calling device.
Audio / Video Device Controller Speaker Display
Device
| |
|(1) INV SDP (m=video, | |
|
| m=audio ) |
| |
| ------------> | |
|
| |2)INV SDP m=audio
| |
| | ------------> |
|
| |3)INV SDP m=video
| |
| | ------------
-----------------------> |
| |
| |
| | (4) 200 OK answer1|
|
| | (audio) |
|
| |<------------------|
|
| | |(5)200
OK answer2 |
| | | (video)
|
| |
<--------------------------------------|
| |
| |
| |
| |
| (6)Parsing and combining of
| |
audio/video SDP at controller |
|
| 200 OK(Combined a/v SDP) |
| |
| <------------------ |
| |
| (7) ACK |
| |
| --------------> |
| |
| | (8) ACK
| |
| | -------------->
| |
| |
| |
| | (9) ACK ------------------->
|
====================================================================
==================================Media
Flow========================
====================================================================
Are there any known issues with this?
Thanks in advance,
Niall