28 Mar
2012
28 Mar
'12
3:27 a.m.
HI
I am trying to do the early media like this:
PSTN/GW1 -> Kamailio -> Asterisk
--> PSTN/GW2
GW1 send invite to Kamilio, Kamilio proxy to Asterisk,
Asterisk reply with 183 ( with to tag=A) and sdp
After the playing some medium, asterisk send 603 reply to Kamailio
Kamilio intercept the 603, and lookup the routing table, decide to send
invite to GW2.
GW2 reply with 180/200OK with to tag=B
In order to properly proxy the msg to GW1, Kamailio seems need to change
the to tag from B to A.
Is it the right way to do? If so how to change the to tag?
or do I need B2BUA ( only signalling) to do the early media?
thanks.
min
28 Mar
28 Mar
10:14 a.m.
There is no need to change the tag. GW1 must accept the 200 OK with
different tag, otherwise the gateway is buggy.
If the gateway is really buggy, the usual workaround is to strip the
to-tag from the provisional responses, i.e. remove the to-tag from
Asterisk's 183 response, e.g. using functions from textops module.
regards
Klaus
On 28.03.2012 02:27, Min Wang wrote:
HI
I am trying to do the early media like this:
PSTN/GW1 -> Kamailio -> Asterisk
--> PSTN/GW2
GW1 send invite to Kamilio, Kamilio proxy to Asterisk,
Asterisk reply with 183 ( with to tag=A) and sdp
After the playing some medium, asterisk send 603 reply to Kamailio
Kamilio intercept the 603, and lookup the routing table, decide to send
invite to GW2.
GW2 reply with 180/200OK with to tag=B
In order to properly proxy the msg to GW1, Kamailio seems need to change
the to tag from B to A.
Is it the right way to do? If so how to change the to tag?
or do I need B2BUA ( only signalling) to do the early media?
thanks.
min
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7:37 p.m.
2012/3/28 Min Wang <ser.basis(a)gmail.com>om>:
In order to properly proxy the msg to GW1, Kamailio
seems need to change the
to tag from B to A.
Totally wrong. Multiple (early-)dialogs are 100% valid according to
RFC 3261. If you find some SIP device failing when it receives
multiple 180/183/200 responses with different To-tag, then drop it
--
Iñaki Baz Castillo
<ibc(a)aliax.net>
29 Mar
29 Mar
1:50 a.m.
Hi Kluas and Iñaki:
Thank you a lot for the information!
min
On 03/28/2012 12:37 PM, Iñaki Baz Castillo wrote:
2012/3/28 Min Wang<ser.basis(a)gmail.com>om>:
In order to properly proxy the msg to GW1,
Kamailio seems need to change the
to tag from B to A.
Totally wrong. Multiple (early-)dialogs are 100% valid according to
RFC 3261. If you find some SIP device failing when it receives
multiple 180/183/200 responses with different To-tag, then drop it
2:14 a.m.
Hi,
On 03/28/2012 06:37 PM, Iñaki Baz Castillo wrote:
2012/3/28 Min Wang <ser.basis(a)gmail.com>om>:
I recently learned that for example Siemens switches implement "Request
Disposition: no-fork" defined in http://www.ietf.org/rfc/rfc3841.txt,
and if for some reason you decide to fork nonetheless on your side,
you'd probably want to do something about the different to-tags
(although you're violating against that specific RFC then). No idea how
such a device would react to not getting a to-tag at all by stripping it
out as Klaus suggested in another response, but at least that Siemens
switch doesn't bail out on getting different to-tags in provisional replies.
Andreas
In order to properly proxy the msg to GW1,
Kamailio seems need to change the
to tag from B to A.
Totally wrong. Multiple (early-)dialogs are 100% valid according to
RFC 3261. If you find some SIP device failing when it receives
multiple 180/183/200 responses with different To-tag, then drop it 
10:32 a.m.
Hello,
On 3/29/12 1:14 AM, Andreas Granig wrote:
Hi,
On 03/28/2012 06:37 PM, Iñaki Baz Castillo wrote:
I
fully agree that devices not supporting multiple to-tags in
provisional replies should be dropped, it will make life easier for
everyone.
Regarding hacks to make an workaround, in many cases I saw devices
requiring to-tag in 183. In that case, a solution can be dropping 183
from reply route and send 180 instead with t_reply(...).
Cheers,
Daniel
--
Daniel-Constantin Mierla
Kamailio Advanced Training, April 23-26, 2012, Berlin, Germany
http://www.asipto.com/index.php/kamailio-advanced-training/
2012/3/28 Min Wang<ser.basis(a)gmail.com>om>:
I recently
learned that for example Siemens switches implement "Request
Disposition: no-fork" defined in http://www.ietf.org/rfc/rfc3841.txt,
and if for some reason you decide to fork nonetheless on your side,
you'd probably want to do something about the different to-tags
(although you're violating against that specific RFC then). No idea how
such a device would react to not getting a to-tag at all by stripping it
out as Klaus suggested in another response, but at least that Siemens
switch doesn't bail out on getting different to-tags in provisional replies. In order to properly proxy the msg to GW1,
Kamailio seems need to change the
to tag from B to A.
Totally wrong. Multiple (early-)dialogs are 100% valid
according to
RFC 3261. If you find some SIP device failing when it receives
multiple 180/183/200 responses with different To-tag, then drop it
3:51 p.m.
2012/3/29 Andreas Granig <agranig(a)sipwise.com>om>:
I recently learned that for example Siemens switches
implement "Request
Disposition: no-fork" defined in http://www.ietf.org/rfc/rfc3841.txt,
Annoying spec. Now the client can tell the proxy "please don't fork"...
WTF?
--
Iñaki Baz Castillo
<ibc(a)aliax.net>
4627
days inactive
4628
days old
6 comments
5 participants
participants (5)
-
Andreas Granig -
Daniel-Constantin Mierla -
Iñaki Baz Castillo -
Klaus Darilion -
Min Wang