[cisco-voip] IP-Phones NAT problem

[Per Carlson]

On Thu, Apr 06, 2006 at 07:18:13PM +0200, Mounir Mohamed wrote:

> Could you clarify more What is the FIXUP

A SIP-aware NAT-implementation. When NAT-ing SIP-signalling you
can't just change the IP-addresses/ports because the signalling
have got IP-adresses in the payload as well.

On a router you will need an IOS/feature set that both supports
SIP-aware NAT *and* FW. You don't need to configure the FW, but
the code is needed to do deep packet modifications.

The SIP-aware NAT feature is in 12.2(something)T and newer.

-- 
Per Carlson, Sr. Network Developer