Hello,
I’m having a problem with getting reliable inbound connections.
Hardware/software details:
PBXnSIP v2.1.14.2498 (Win32) (Win XP Pro)
Sonicwall TZ170 - firmware SonicOS Enhanced 3.2.3.0-6e
Linksys SPA942 Phones - firmware version 5.2.2(a)
Linksys WRV 200 Routers - Firmware 1.0.39
VoIP provider is Callcentric
VoIP Layout Details:
The Sonicwall is the main router with the PBXnSIP hanging off of it. The Sonicwall is configured to pass all PBXnSIP ports to the PBX PC. There are 2 branch offices that connect via a VPN provided by the Linksys router to the sonicwall. Each office has a Linksys phone.
VoIP problem:
When no inbound calls are placed for an undetermined about of time, the first inbound call is either unanswered after a long silence or is answered by CallCentric’s voicemail. If a second inbound call is placed right away the PBXnSIP will pick up the call in a normal time. All incoming calls for the next undetermined amount time, are answered as normal.
Trouble Shooting details:
This problem appears to be corrected by enabling SIP Transformations under the VoIP section of the Sonicwall. However, when I enable this, both branch offices will lose audio both ways. The phones are still communicating with the PBX because missed call notifications are e-mailed when attempting to call one of the branch offices.
Any help you can provide will be greatly appreciated.