Asterisk sending back 401 on fragmented INVITEs

I have a few invites a day that come into my asterisk server, and these invites have been forwarded and subsequently the packet is bigger than 1500 bytes, so it comes in two UDP fragments, one that is 1514 bytes on the wire and one that is 60 bytes, and for some reason my asterisk server immediately returns error 401, not authorized.

Is this a problem with the forwarding (i am suspicious about maybe the headers being wrong because the FROM field shows 192.168.x.x) or is this a packet recombination problem. I thought the underlying ethernet drivers would automatically reassemble any fragmented packet.

this problem is driving me crazy, a reward to someone who helps me solve this!

if you are local, a meal! or perhaps a consulting contract in the future!

The underlying network drivers will reassemble the packet, but there will be a limited buffer size. As you didn’t say which SIP driver you are using, it’s not worth checking the code to find the limit.

not sure what you mean by SIP driver. I am using stock FreePBX distribution

chan_sip or pjsip

We don’t know about FreePBX here.