[OpenSIPS-Users] detect_hold()

[Iñaki Baz Castillo]

2010/7/6 Bogdan-Andrei Iancu <bogdan at voice-system.ro>:
> Hi Jesse,
>
> A re-INVITE putting a call "on hold" has IP 0.0.0.0 in the SDP (c line)

Hi bogdan, such mechanism (putting 0.0.0.0) is deprecated and just
valid according to RFC 2543 (old SIP RFC):


RFC 3264:

8.4 Putting a Unicast Media Stream on Hold

   If a party in a call wants to put the other party "on hold", i.e.,
   request that it temporarily stops sending one or more unicast media
   streams, a party offers the other an updated SDP.

   If the stream to be placed on hold was previously a sendrecv media
   stream, it is placed on hold by marking it as sendonly.  If the
   stream to be placed on hold was previously a recvonly media stream,
   it is placed on hold by marking it inactive.

   [...]

   RFC 2543 [10] specified that placing a user on hold was accomplished
   by setting the connection address to 0.0.0.0.  Its usage for putting
   a call on hold is no longer recommended, since it doesn't allow for
   RTCP to be used with held streams, doesn't work with IPv6, and breaks
   with connection oriented media.


-- 
Iñaki Baz Castillo
<ibc at aliax.net>