Bldg A: Sl1100, 12 trunks, 25 digital, 7 voip phones, AT&T DSL.

Bldg B: 8 Voip phones, Nat to Bldg A, AT&T DSL.

All working fine for 3 years.

Company bought out. New IT dept gets AT&T fiber in Bldg B and a Sonic Wall, fiber not available to bldg A.

Plan is to use the fiber in bldg B for all users in both bldg with 400 meg radio link between sites.

Soon as they changed to fiber and Sonic Wall, voip phones in bldg B started dropping every 5 to 10 minutes.

Radio link was up so they connected it to the network in bldg A.

Bldg A 172.16.2.xxx Bldg B 1 192.168.0.xxx

192.168.0.0 Put in 10.58 slot #1.

Configured remote phones same as those in bldg A. Data clear, hard reset, DHCP on sip server 172.16.2.240

Still drop in same amount of time.

UDP timeout on Sonic Wall changed to 180 by IT team.

AT&T router is not bridged but has what is called PASSthrough, assume it is the same thing.

Remote phones get 192 ip's, Dhcp on sip server 172.16.2.240

Main bldg sl1100 172.16.2.240 voip DB 172.16.2.250

Any suggestions?

Confirm ALG on the sonic wall is disabled

Hopefully they understand the Sonicwall is COMPLETELY at fault and you bill for this.

10-58 (the systems SHOULD come with this by default)

10.0.0.0 - 255.0.0.0
172.16.0.0 - 255.240.0.0
192.168.0.0 - 255.255.0.0

15-05-47 Set to 90
15-05-48 Set to 90

After converting both networks to same IP scheme and running Sonic Wall, found two unknown devices plugged in at ksu side of network that were killing the system, even the computers could not reach the other side of the radio.
Trouble shooting 101, unplug everything, plug in one at a time.

Trump completely at fault here.