Hi,

Since several people have suggested to avoid SIP ALG at all costs, I have disabled it and banged my head some more!  Without SIP ALG, only one of my Polycom 335s can Register.  The other 5 fail. (With SIP ALG they all register fine).

Now I have found that changing:

SETTINGS>SIP>LOCAL SIP PORT> to a UNIQUE port (5066 in this case)

And

SETTINGS>NETWORK>NAT>SIGNALING PORT> to the same UNIQUE port

I got a second phone to REGISTER and exchange calls!

When I say unique port, I mean unique to all the phones on this NAT Router.

My question is “Is that fine?”

I just want to know if there are limitations on the SIP Port number?  Are there issues I should watch out for.

Thanks,

Sean