I have recently installed 4 Yealink Phones (varying models - x2 T20, x1 T46, T26) they have been great when they are working, however they seem to drop the registration overnight. I have tried a couple of fixes but nothing seems to help. So far I have:
- Upgraded the firmware
- Disabled SIP ALG
- Tried different ports (5060, 50600 & 5061)
- Changed server registration interval to 180
Other information that might be useful is that the router is a draytek 2710. The phones are acquiring an IP address from the DHCP server rather than a static IP.
If there is any information I have missed please let me know.