nat translation failed

nikolay-shopik · ‎03-18-2008

Hi everyone,

I have SCCP phone (7940) which behind 851W and have usually "translation failed" erros if I debug ip nat, which cause some packets to drop.

I've tested before with 7911 and don't have such issues which cause phone to unregister because of packet drops.

Any ideas what could be wrong?

jsivulka · ‎03-24-2008

The following are bugs related to your issue.

CSCdk26867

CSCdv40492

nikolay-shopik · ‎03-24-2008

These seems to be very old bugs and fixed long time ago. That's probably something new i suppose.

paolo bevilacqua · ‎03-24-2008

Don't bother, for some reason people from that firm like mentioning bugs at random.

Now, can't you just set a gre tunnel between 851 and cme, and so forget all and any NAT issue ?

nikolay-shopik · ‎03-24-2008

I've already running ipsec tunnel but I have to changes source address of packets. But this force me to make another tunnel from 1801 (which working fine behind nat) only for phones.

This increase latency and jitter (ip telephony forbidden in UAE) ISP adds jitter and latency in most encrypted connections.

It's seems I have no choice but make another tunnel or upgrade 851 to 871 with advanced ip services.