Switching DDIs from one SIP trunk to another

[RobC]

I need to move several DDIs from one SIP trunk to another (from a different carrier). I have arranged the necessary number ports.

I'm looking to provide a seamless switchover so I'd like to set up the DDIs on the new SIP trunk in advance. Is it OK to set up the DDIs on the new SIP trunk while they're still active on the old one or will this confuse 3CX?

 

[leejor]

I can't see there being an issue. If a match is found, the call should direct to the extension based on the rule. In theory, using wildcards, you could have two different numbers, with the same last 3, or 4 digits, from multiple SIP providers, going to the same extension.

 

[YiannisH_3CX]

Hello @RobC

Having the same DIDs under 2 trunks might cause routing issues in 3CX depending on the trunks you are using and what the PBX uses to match the call to a trunk. If you are using authentication based trunks that support rinstance for example then should have no issues. The following link explains how the PBX identifies inbound calls and should help you figure out if you will face any issues or not. https://www.3cx.com/docs/sip-trunk-inbound-calls/