Vodafone VOIP ?

I recently changed my broadband and phone to Vodafone. I live in the Dublin area. The system they use is some sort of VOIP system where the phone line runs through the broadband modem. Previously my phone was running from the socket in the wall. Is there any major advantage/disadvantage to this VOIP type system. I have two extensions in the house from the main phone and with this system these extensions will not work. I would appreciate any advice as I am thinking of getting them to change back to the socket on the wall.

Alarm systems with phone line monitoring won't work on the VOIP service either. Broadband performance is generally a lot better with the VOIP service.

They can switch it back if you request, or you could get a multi-set of cordless phones that work off a single base station you can plug into the router.

If I get a multi-set of cordless phones, Is it possible for two people to listen/participate in the call at the same time from the 2 cordless phones?

The better ones will support multi-party calls.