I'm doing some work, with Legacy Cisco phones, its a long story but I need to manipulate signaling due to firmware limitations.

I am looking to implement a workaround, whereby I need to modify an ACK, so that it sends the RURI is sent to port 5060, and the destination Port at the IP layer is unchanged, I can do this with static values as below;

In terms of doing this for multiple sites I need to use pseudo variables, so I wondered how this could be achieved, as t_relay or forward dont support dynamic values to this point, or do they?

Any comments would be great.

Many thanks

Jon