What's happening?

You've setup call forwarding from a different phone system into bvoip, but when you ring that it goes to some random extension or unexpected destination, instead of the inbound rule you've set for the destination number that is getting forwarded to.

The issue is due to the sender system sending an unexpected value in SIP invite, usually using the original number that was dialed.

Depending on where the forward is coming from, there are a couple different ways to fix this.

How do I fix it?

Carrier Forwarding Settings

Google Voice

Customers of Google Voice need to enable the setting “Show my Google Voice number as caller ID when forwarding calls” under Settings > Calls, and that should allow forwarded calls to follow the expected rules.

Inbound Rules

You can follow our Setting Inbound Call Rules guide to add an additional inbound rule for the original number that was getting dialed. This should allow the call to flow properly in most circumstances.

Route of Last Resort

Inside of each SIP Trunk in the phone system, there is a Route Calls To section under the General tab of the trunk. This route is used for any calls that don't follow one of the other inbound rules, so you can configure this to point at the same destination as the number you were trying to forward to.

Only one of these rules exists per trunk, so if you're doing multiple number forwards with different destinations then make sure you add inbound rules like mentioned above.