We currently do not use an RTP proxy in our service (so the audio does not ride our internet bandwidth).
Our biggest issue at the moment is the redundancy between two SER servers in dealing with symmetric NATs (specifically dealing with the individual SER server unique IP addresses and the far end customer's symmetric NAT).
If we were to use an RTP proxy, as a backup mechanism for dealing with NATs, would this alleviate the issue of multiple SER servers and symmetric NATs?