I've installed a Cyberdata SIP Paging Adapter on a hosted system (Jive). When I installed the unit on my home network it worked flawlessly.
When I installed it at the customer's site, it will only work for about 5 minutes, then it loses its SIP registration.
I've tried many troubleshooting steps- use static IP, change to DHCP, change DNS settings, look for IP conflicts. Everytime we change the IP address it will re-register ok, but again only for about 5 minutes.
I'm not the IT guy, but he is helping look at things.
Other phones (20) and (4) SIP door intercoms (also Cyberdata) work fine. Only the paging adapter has problems.
Again, when I take it home and put it on my home network it works flawlessly for days at a time.
Router is a Sonicwall.
Looking for any clues that we could check, either on the network side or in the SIP device itself.

Charles