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Wireshark-users: Re: [Wireshark-users] Q.931 called party information to SIP

From: mixalis <mixalis.x@xxxxxxxxx>
Date: Thu, 13 Mar 2008 22:15:21 +0200
Hi Jaap,

I'm sorry i didn't give the whole picture. The call is first converted from H323 to SIP, then back to H323. I'm tracing the H323 messages after the conversion from SIP, and the flags are set the same as in the original H323 setup message. For example, if i have the flags set as "International/ISDN" in the original Q.931 header, after the conversion to SIP and back to H323, these flags do not change. Let me clarify that this is exactly the way i want it to behave, i'm just curious as to why/how it does this. Another point of interest is the topology. The call enters an endpoint (the h323 part). That endpoint talks via SIP with an MSC controller (which handles the routing/billing procedures), and that MSC controller talks with the terminating endpoint (via SIP), which in turn sends the call to its destination by H323. Something like this:
caller - h323 - endpointA - sip - MSC - sip - endpointB - h323 - destination


Thanks
Michalis
Date: Thu, 13 Mar 2008 18:35:43 +0100
From: Jaap Keuter <jaap.keuter@xxxxxxxxx>
Subject: Re: [Wireshark-users] Q.931 called party information to SIP
To: Community support list for Wireshark
	<wireshark-users@xxxxxxxxxxxxx>
Message-ID: <47D965EF.5070803@xxxxxxxxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Hi,

Called party number usually translates into the INVITE URI. The number plan and type are not converted, maybe only used to verify that a URI can be composed of the called party number information, or, if it's an advanced gateway, could select the URI format based on the plan and type, but I've never seen that.

Thanx,
Jaap

mixalis x. wrote:
> Hello all,
> > I have an H323->SIP gateway and i'm trying to figure out how it maps the > "Called Party/Number plan/Number type" information element, found in the > original Q.931 setup message, to the SIP Invite message. I have the > traces from both the Q931 setup packet (where i can see the number > plan/number type) and the SIP Invite packet, but i cannot locate this > specific information inside the SIP message. > > Any ideas? > > tia
> Michalis
>