IP Phones engaged tone??

[MitecNZ]

Hi, i have a site using remote ip phones 5610's

Ip Small office v4.2

these have been working perfectly well over the VPN link, until last week when they try dialing an external number, disconnected tone.

they can call the extensions on the pabx fine, and transfer etc, and extension can call them fine.

just last week, noticed when call out, externally, which has been working perfectly fine before, this engaged tone has appeared?

any ideas?

i have the codec set to automatic, as there has been no issues in the past

 

[MitecNZ]

False Alarm, I ran system status, and noticed they werent logged in, coming up as the NoUSER extn, got them to log in, and all go again