Broadband providers that allow SIP

3CX online recommend that SIP should only be configured with business class broadband and not on a residential service.Sometimes there are situation such as remote extensions and home worker environments where it is good to be aware of the situations that may get in your way. The following table will be updated as regularly as we can.


Broadband Provider Blocked by ISP Blocked by CPE* Notes
SKY  unknown  Yes  
BT  unknown  Yes By replacing the router
Virgin (superhub)  No  Yes By entering the superhub into modem mode and using a supported Firewall/Router then SIP is possible.

*CPE = Customer Present Equipment and generally refers to the vendor supplied modem/router.