I've been using 2talk for years with 4 phone lines, without issue, using an old Grandstream GXP2000 device (for 3 office lines), and a Grandstream HT801 (for 1 home line).

Just got a new Grandstream GXP2170 phone (to replace the GXP2000), as the gxp2000 was getting old and having sound issues.
But cannot make outbound calls via the 2170, only receive incoming calls.

I'm using all the same settings as the old GXP2000, e.g. Sip Server / Outbound proxy = tls.2talk.co.nz, and correct user ID and password.

The 2talk portal shows the line as registered, and I'm only trying one line by itself first (rather than all lines).

Syslog debugging gives me this error when attempting an outbound call from an 06 number to a 021 mobile number (any outbound number fails):
(removed the ip and numbers)

(542)SIP/2.0 401 Unauthorized..Via: SIP/2.0/UDP xxx.xx.xxx.xx:5062;branch=z9hG4bK408286934;received=xxx.xx.xxx.xx;rport=5062..From: "XXX" <sip:06xxxxxxx@tls.2talk.co.nz>;tag=1407541580..To: <sip:021xxxxxx@tls.2talk.co.nz>;

I've tried changing my main 2talk password, and tested this successfully back in the old gxp2000 device, but the gxp2170 still fails to make outbound calls, and gives the error above.

Tried 2talk support chat, but as its the weekend there is no response.

Anyone here using one of the Grandstream GXP21xx devices?