Adding to what Brett says...
An issue with 3261 is that there is no precise definition of the
duration over which a "Supported:xyz" is applicable. It might be for the
lifetime of the device sending it, it might be for the duration of the
dialog in which it is sent, or it might only be for the d
> Is it OK to include Require header with 100rel
> in the re-INVITE, UA1 has already showed that
> it supports this extension.
Yes; however you might receive a 420.
> Why should UA1 reject this message with 420 response.
Among other potential reasons, a B2BUA is involved and re-INVITE reache
Hi
>From the call flow you mentioned , it seems UA2 dont support 100 rel
extension .
As provisional response coming from UA2 was not reliable even when UA1
shows support for this extension
Thats why UA2 sending 420 response .
I guess its Ok to send Require:100 rel in Reinvite even its not required
Hi
I have following scenario -
1. UA1 sends INVITE to UA2 with Supported: 100rel header
2. Call is established (180, 200, ACK exchanged)
3. UA2 wants to put the call on hold and sends re-INVITE to UA1. This
message contains Require: 100rel header.
4. UA1 rejects this request with 420 Bad Extension
