asterisk users - Jul 2007 - [Asterisk]Asterisk's behavior of a simple call

Hello,

I tried to configure a very simple case of Asterisk using SIP

userA --- Asterisk server ---- userB

sip.conf

[userA]
type=friend
username=userA
host=dynamic
nat=no
context=test

[userB]
type=friend
username=userB
host=dynamic
nat=no
context=test

In extensions.conf
[test]
exten => 1000,1,Dial(SIP/userA)
exten => 2000,1,Dial(SIP/userB)

I make a call from userA to userB, it works, but I have 2 questions:

1/ By verifing with Wireshark, I see that the CallID of the INVITE message
sent from userA to Asterisk is different from the CallID of the INVITE message
sent from Asterisk to UserB.
Is it possible to configure Asterisk as an "normal SIP proxy"  (it
just forwards SIP messages)?

2/ After sending the INVITE message to UserB, Asterisk send another INVITE
message to userA with the same
CallID as the CallID in the INVITE message from userA to Asterisk. I don't
understant, could you please explain it to me?

Thanks,
Viet




       
____________________________________________________________________________________
Choose the right car based on your needs.  Check out Yahoo! Autos new Car Finder
tool.
http://autos.yahoo.com/carfinder/
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
http://lists.digium.com/pipermail/asterisk-users/attachments/20070716/d541e6d0/attachment.htm

On Mon, 2007-07-16 at 03:01 -0700, Tuan Viet Nguyen
wrote:
> I make a call from userA to userB, it works, but I have 2 questions:
> 
> 1/ By verifing with Wireshark, I see that the CallID of the INVITE
> message
> sent from userA to Asterisk is different from the CallID of the INVITE
> message sent from Asterisk to UserB.
> Is it possible to configure Asterisk as an "normal SIP proxy" 
(it
> just forwards SIP messages)?
Asterisk is not a SIP proxy.  Asterisk is a back-to-back user agent.
This means that Asterisk will always create two seperate SIP calls, and
bridge them.  If you're looking for a SIP proxy, I recommend you try
either SER or OpenSER.
> 
> 2/ After sending the INVITE message to UserB, Asterisk send another
> INVITE message to userA with the same 
> CallID as the CallID in the INVITE message from userA to Asterisk. I
> don't understant, could you please explain it to me?
This is a most likely a *re*-invite.  Asterisk is asking userA to try to
send it's media directly to userB, so that only the call signalling goes
through Asterisk, and not the media.

-- 
Jared Smith
Community Relations Manager
Digium, Inc.
>