[Serusers] HELP: Via in multi-host SER configuration

Daniel-Constantin Mierla Daniel-Constantin.Mierla at fokus.fraunhofer.de
Fri Dec 17 07:23:02 CET 2004

the balancer is broken, the reply must follow back the path the request 
had. Otherwise the proxies on the path should retransmit the request 
until they get a reply or a timeout. Top most via header in reply must 
include the ip address of the current proxy.


On 12/16/04 22:27, Java Rockx wrote:

>Hi all.
>We have two ser-0.8.99-dev24 servers configured behind a load balancer, but we are having
>record-route problems whereby an INVITE gets sent to an Asterisk server and the "100 Trying" reply
>from Asterisk gets sent to the other SER proxy because the load balancer chooses to send the 100
>reply to the other ser proxy.
>Below is an INVITE with a Record-Route and two Via headers. In this message the IP is
>the **virtual** public IP of the SER proxies.
>Is the top VIA (ie, Via: SIP/2.0/UDP the reason the "100 Trying" message gets sent
>to the other SIP proxy? We believe that if this VIA had the physical IP of the ser proxy that sent
>them message - then all would be fine.
>We've played with record_route_preset("xxx.xxx.xxx.xxx") but that doesn't seem to help with
>regards to changing the top via.
>Can anyone give some words of wisdom?
>U ->
>INVITE sip:4075551212 at;user=phone SIP/2.0.
>Record-Route: <sip:;ftag=4d0c0449837b0fce;lr=on>.
>Via: SIP/2.0/UDP;branch=z9hG4bK7277.557b17d3.0.
>Via: SIP/2.0/UDP
>From: <sip:4075551212 at sip.mycompany.com;user=phone>;tag=4d0c0449837b0fce.
>To: <sip:4075551212 at sip.mycompany.com;user=phone>.
>Contact: <sip:34075551212 at;user=phone>.
>Supported: replaces.
>Proxy-Authorization: DIGEST username="4075551212", realm="sip.mycompany.com", algorithm=MD5,
>uri="sip:4075551212 at sip.mycompany.com;user=phone",nonce="41c1f8a5c69796cff47ad459a19632f0d31105ee",
>Call-ID: 71cfc2d5a0fbdae1 at
>CSeq: 12663 INVITE.
>User-Agent: Grandstream BT100
>Max-Forwards: 16.
>Content-Type: application/sdp.
>Content-Length: 411.
>X-host: .
>P-hint: 3 && Record-Route.
>o=3212514234 1 8000 IN IP4
>s=SIP Call.
>c=IN IP4
>t=0 0.
>m=audio 35338 RTP/AVP 98 18 15 4 2 9 0 8 101.
>a=rtpmap:98 iLBC/8000.
>a=fmtp:98 mode=20.
>a=rtpmap:18 G729/8000.
>a=rtpmap:15 G728/8000.
>a=rtpmap:4 G723/8000.
>a=rtpmap:2 G726-32/8000.
>a=rtpmap:9 G722/8000.
>a=rtpmap:0 PCMU/8000.
>a=rtpmap:8 PCMA/8000.
>a=rtpmap:101 telephone-event/8000.
>a=fmtp:101 0-11. 
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