[Asterisk-Dev] IP-ID in RTP UDP packets

[Aj]

Hi All,

I am doing some testing with the asterisk server and have been
monitoring the packets exchanged during a SIP-ZAPTEL phone call.

I see that the IP-ID in all of the RTP/UDP/IP packets are set to zero.
After some googling, I have learnt that some of the linux
implementations set the IP-ID to 0 (if the DF bit is set in the IP
header) if the two hosts exchanging data are on the same subnet.

I see this happening in the RTP packets of the phone calls being made.

Is there a way to:
- force linux to send the right IP-ID?
- or to set the DF bit to 0 in an attempt to make the IP stack to put
in the right IP-ID?

Linux kernel being used: 2.4.20-8.

Please let me know,
Thanks,
Ajay