Hi can anyone maybe assist me, I have a customer with 11 branches, 2 running on OS7200 1 on OS7070 and the rest on OS7030 double cab config. The 7200 & 7070 is working 100%. The OS7030 sites keep on dropping the SIP service and doesn't recover unless I Disable and then Enable the SIP service in MMCXXX. I've done the following with no sucsess:

1) Upgraded firmware to V4.41b
2) Removed inter-branch calling and replaced with speed dials.
3) Changed SIP providers
4) Ran traces using WireShark (all test ok)
5) Tested ADSL links (all test ok)
6) Changed ADSL routers
7) Minimized the SIP trunks to 3
8) Deafault system to run on minimum config, changing only the IP, Slave IP, Ext Range.
9) With single cab config the OS7030 work 100% without dropping the SIP service.
10) Removed all unused MGI and SIP numbers.
11) Replace the system with a new OS7030 in double cab config.

I thought that I had an authentication problem, but this has also been ruled out. The ADSL links is 512k Download and 4096k Upload.

Thank you