We have OpenSIPS in front of FreeSWITCH, phones register to OpenSIPS, OpenSIPS sends all calls to FreeSWITCH. the way we have it set up is that both OpenSIPS and FreeSWITCH auth all the invites (we have it like this for a reason). this setup works fine (with Yealink at least). Problem we have is with Polycom phones, the phone registers just fine but can't make calls. When OpenSIPS gets the INVITE it responds with a 407, to which the Polycom responds, OpenSIPS is then sending the call to FreeSWITCH which sends a 407 again, OpenSIPS proxies it back to the polycom, however the Polycom does not respond to the challenge. I don't think this is a FreeSWITCH problem, I would still like to hear if anyone has an idea how I can get this working (config option?) Thanks