[Asterisk-Users] RE: Asterisk-Users Digest, Vol 8, Issue 152

[Wei Su]

I understand Asterisk is more like a B2BUA. But when this INFO request is
sent to asterisk, asterisk is supposed to bridge the request to the other
endpoint, right? In what situation, it decides to send a reply; in what
situation, it decides to bridge the request?

What is the role of gateway in SIP world, a proxy, a B2BUA or something
else?

Thank  you,

Wei

Date: Fri, 18 Mar 2005 12:51:28 -0600
From: Eric Wieling <eric at fnords.org>
Subject: Re: [Asterisk-Users] Asterisk handling of SIP info
To: Asterisk Users Mailing List - Non-Commercial Discussion
	<asterisk-users at lists.digium.com>
Message-ID: <423B2330.9090705 at fnords.org>
Content-Type: text/plain; charset=us-ascii; format=flowed

Asterisk is not a SIP proxy.

Wei Su wrote:

> We encouter a situation where we need to use SIP info to convey infomation
> for one end point to another endpoint. I use asterisk to do the test and
> find asterisk does not forward the SIP info to another endpoint, but act
as
> UAS and returns a 4xx error message. I think asterisk is not right to
handle
> this SIP info message. 
>  
> In RFC 3261 Page 70 "This protocol is designed to be extended. Future
> extensions may define new methods and header fields at any time. An
element
> MUST NOT refuse to proxy a request becasue it contains a method or header
> field it does not know about". In this case, asterisk does not understand
> this INFO message, so it acts as a UAS instead of proxy.
>  
> How to let asterisk just forward this request to the other endpoint and
> instead processing it as a UAS?
>  
> Thank you,
>  
> Wei
>  
>  
>  
>  
> Here is the log from the asterisk server:
>  
> Mar 17 12:01:31 WARNING[2804]: chan_sip.c:6134 receive_info: Unable to
parse
> INFO message 
>  
>  
> Here is the trace:
>  
>  
> Frame 96 (808 bytes on wire, 808 bytes captured)
> Session Initiation Protocol
>     Request-Line: INFO sip:6002 at 192.168.10.90 SIP/2.0
>         Method: INFO
>         Resent Packet: False
>     Message Header
>         Call-ID: 60b8596c-4135c-c0a81e68 at 192.168.10.90
>         From: Demo2<sip:6003 at 192.168.10.90;user=phone>;tag=221a0-a1cf
>             SIP Display info: Demo2
>             SIP from address: sip:6003 at 192.168.10.90
>             SIP tag: 221a0-a1cf
>         To: <sip:6002 at 192.168.10.90;user=phone>;tag=as6b294484
>             SIP to address: sip:6002 at 192.168.10.90
>             SIP tag: as6b294484
>         CSeq: 102 INFO
>         Via: SIP/2.0/UDP 192.168.10.164:5060
>         Contact: Demo2<sip:6003 at 192.168.10.164:5060;user=phone>
>         Max-Forwards: 70
>         Supported: timer
>         Proxy-Authorization: Digest
>
username="6003",realm="asterisk",uri="sip:6002 at 192.168.10.90",response="034d
> 6b15ec1b2fa91f59c55d51c0a8e7",nonce="70c7fe86"
>         Content-Type: application/media_control+xml
>         Content-Length: 195
>     Message body
>         <?xml version="1.0" encoding="utf-8" ?>\n
>          <media_control>\n
>           <vc_primitive>\n
>            <to_encoder>\n
>             <picture_fast_update>\n
>             </picture_fast_update>\n
>            </to_encoder>\n
>           </vc_primitive>\n
>          </media_control>
>  
> 
> Frame 97 (430 bytes on wire, 430 bytes captured)
> Session Initiation Protocol
>     Status-Line: SIP/2.0 415 Unsupported media type
>         Status-Code: 415
>         Resent Packet: False
>     Message Header
>         Via: SIP/2.0/UDP 192.168.10.164:5060
>         From: Demo2<sip:6003 at 192.168.10.90;user=phone>;tag=221a0-a1cf
>             SIP Display info: Demo2
>             SIP from address: sip:6003 at 192.168.10.90
>             SIP tag: 221a0-a1cf
>         To: <sip:6002 at 192.168.10.90;user=phone>;tag=as6b294484
>             SIP to address: sip:6002 at 192.168.10.90
>             SIP tag: as6b294484
>         Call-ID: 60b8596c-4135c-c0a81e68 at 192.168.10.90
>         CSeq: 102 INFO
>         User-Agent: Asterisk PBX
>         Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER
>         Contact: <sip:6002 at 192.168.10.90>
>         Content-Length: 0
> 
>