Join the Conversation

To sign in, use your existing MySonicWall account. To create a free MySonicWall account click "Register".


VoIP calls won't transfer

We had a VoIP system installed last year and it was working before lockdown and home working. Since returning to the office, it still works fine, except it doesn't transfer calls if the transferring phone is in the office. The calls get left in limbo for a while. If we take the handset out of the office, it's fine.

The office has a leased line coming in, through a Cisco ISR 1100 router in to a TZ400. No domain or server, the Sonicwall is also the DCHP &c. So the Sonicwall appears to be the possible problem.

Category: Entry Level Firewalls


  • Options

    Hello @PeteB_S4,

    Welcome to SonicWall community.

    We would need to check if any of the firewall security checks or SIP transformation is causing such a problem/delay. It would be ideal to perform packet capture in real-time while the transfer is made to see what is exactly happening. The best way to figure that out would be reaching out to support team.


    Shipra Sahu

    Technical Support Advisor, Premier Services

  • Options
    SliderhomeSliderhome Enthusiast ✭✭
    edited December 2020


    Try to disable "Enable consistent NAT"

Sign In or Register to comment.