do you have some document that will let you know how to register third party SIP phones (polycom sound ip 330) with CME version 4.2
It looks like this:
voice service voip
voice register global
source-address 188.8.131.52 port 5060
voice register dn 1
voice register pool 1
id mac XXXX.XXXX.XXXX
type ! If it's 3rd party, omit this
number 1 dn 1
username X password X ! Required if IP phone's address is on different subnet than SIP CME source address
This is the minimum required configuration for SIP CME.
By the way, it's not officially TAC supported, but you can usually get it to work anyway.