How large are the sip messages? Do you have an SBC deployed at one/both locations?

I've observed that SER will truncate message that it forwards if they become too large. This is usually happens with two clients behind an SBC when large via parameter have been inserted to maintain SBC state within the sip dialog. Both Ingate and Jasomi products do this for example. The result of these large via's is that the message become too large and SER tend to truncate the SDP portion of the message. The connection generally sets up with regard to signaling, but the media path always fails.

I have observed this behavior while making a sip to sip call between two xten clients, both positioned behind an ingate separator. Both clients were registered to the same SER with RtpProxy (Redhat Enterprise AS 3.0).

-----Original Message----- From: Andrei Pelinescu-Onciul [mailto:pelinescu-onciul@fokus.fraunhofer.de] Sent: Monday, November 01, 2004 12:32 PM To: Bastian Schern Cc: serusers@lists.iptel.org Subject: Re: [Serusers] UDP Fragmentation Problem

On Oct 30, 2004 at 01:28, Bastian Schern ml01@in-bln.de wrote:

Hi everybody,

I've got no success to get a friend in Bogota (Colombia) connected to

my

SER. He has got a ISDN Internet connection and the UDP packets will be

fragmented. It seems that the MTU of this connection is round about

400

to 500 Bytes. Therefore most UDP-SIP packages are fragmented. Is SER not able to handle fragmented UDP packages?

The packets are defragmented by the ip stack of the OS, so ser doesn't really care if they arrive fragmented or not.

Is it possible to use SIP over TCP with X-Lite? Or has somebody another hint for me?

If you plan to use TCP, keep in mind that nat traversal won't work (if you use it).

Andrei

_______________________________________________ Serusers mailing list serusers@lists.iptel.org http://lists.iptel.org/mailman/listinfo/serusers