Dear Alex;
Thanks for your kindly reply.
Please explain for me what do u mean exactly in "a la"
in the following sentence u wrote it below?
" in SIP, this can be done via
"re-INVITEs" a la the canreinvite= option for SIP
peers in sip.conf"
Another thing, do u mean that it is easier (better) if
we need H.323 endpoint to talk with SIP endpoint then
we use full proxy (signaling + media) so that will
solve miss compatibility issues?
By the way: Asterisk allow H.323 to talk with SIP?
Regards,
-------------------
IP Telephony and Contact Center Engineer
Eng. Bilal Ghayad
Mobile: 00965 9849460
Bilal,
Asterisk is an IP PBX and thus a back-to-back user
agent; by default,
it
will proxy media. The only way to disengage it from
the media stream
is
to use signaling protocol-specific mechanisms to coax
the endpoints
into
talking to each other directly; in SIP, this can be
done via
"re-INVITEs"
a la the canreinvite= option for SIP peers in
sip.conf. The H.323
stack
in Asterisk may or may not have a similar option, and
it may or may not
be
compatible with SIP on a signaling level. That's if
you're connecting
one
endpoint that's H.323 and one that's SIP. I imagine
there's probably a
way to do media stream handoff between two legs that
are natively H.323
on
both ends. But that's the determinant.
Also, remember that even if you hand off the media,
Asterisk still
stays
in the signaling path. This is all the more true if
you're using it as
a signaling gateway between heterogenous protocols.
-- Alex
--
Alex Balashov
Evariste Systems
Web : http://www.evaristesys.com/
Tel : +1-678-954-0670
Direct : +1-678-954-0671
____________________________________________________________________________________
Take the Internet to Go: Yahoo!Go puts the Internet in your pocket: mail, news,
photos & more.
http://mobile.yahoo.com/go?refer=1GNXIC
Bilal, On Fri, 13 Jul 2007, bilal ghayyad wrote:> Please explain for me what do u mean exactly in "a la" > in the following sentence u wrote it below? > > " in SIP, this can be done via > "re-INVITEs" a la the canreinvite= option for SIP > peers in sip.conf"It is an English colloquialism that enjoys wide currency; stolen from French, where it means "in the manner of" or "in the style of," for instance, "a la proven?ale" ("country style"). So, in this case I mean that re-INVITEs are accomplished _by way of_ the 'canreinvite' option. Despite the nomenclature, 'canreinvite' in sip.conf actually means not merely "CAN attempt to re-INVITE" but "WILL attempt to re-INVITE as a point of default behaviour."> Another thing, do u mean that it is easier (better) if > we need H.323 endpoint to talk with SIP endpoint then > we use full proxy (signaling + media) so that will > solve miss compatibility issues?Well, an H.323 endpoint cannot speak directly to a SIP endpoint without a signaling gateway to convert the messages. If you are referring purely to passing RTP media, I suppose it does not matter, if you can broker that handoff somehow between H.323 and SIP. I am not sure if Asterisk has this capability.> By the way: Asterisk allow H.323 to talk with SIP?In principle, yes. Asterisk can act as an H.323 gatekeeper, although not as an endpoint (which is irrelevant to your purpose anyway). By far the easiest and cleanest solution is to run both the signaling and the media through Asterisk, if you're making a SIP <-> H.323 call. This is the approach least likely to cause any compatibility issues since Asterisk is intermediating in the transaction, and I am not sure if an alternative is even possible. -- Alex Balashov Evariste Systems Web : http://www.evaristesys.com/ Tel : +1-678-954-0670 Direct : +1-678-954-0671