Good day all, before I ask my question I'd like to thank the regulars of the forum for all I've learned reading your replies. I have a 3cx free setup where there's some ring groups connected to external lines. When I call one of these numbers, all of the phones display the ring group name as the call source, followed by the caller number, with the exception of the siemenc c450 ip, that displays 'undefined. The siemens workds correctly and can call and receive calls, but the 'undefined' display is a big problem since the operator can't tell which group is the one redirecting to him (multiple groups ring this phone, but the problem exists even with a single group). I must add that this phone is used in a different network than the 3cx server, so it's using stun.3cx.com as a stun server. Absurdly, the display shows: Code: caller number Undefined <= this is the group name in all other phones For IP Hopefully somebody can help. Thanks in advance.