Quote from: drgeoff on October 05, 2015, 05:50:24 PM
I think sharad is asking whether (if he wanted Comcast Voice again) he could obtain the necessary Comcast Voice credentials and enter them into his Obi and thus obtain Comcast Voice without using a Comcast cable modem with integrated VoIP.
As I know zero about Comcast I'm not going to attempt any answer to that.
I assumed you weren't familiar with Comcast, given that you're in the UK (correct?) So, that's why I stepped in to help. Forgive me if you already know some or all of this, but here goes:
Comcast, like other US Cable service providers, tries to make their service harder to leave, by offering "triple play" bundles of television, internet broadband and telephone service, at a better price than the individual offerings if purchased separately.
Their telephone service is SIP VoIP-based, but it is not a typical, open-credential service delivered via generic ATAs over the public internet. Instead, they remotely provision the service in the cable modem box, which has an optional built-in ATA function. In the US, all cable service providers use the same type of modems, which are certified by their industry standards group, DOCSIS. Consumers can either rent the modem from the provider or buy their own. ARRIS (a spin-off of Motorola) is the industry leader. Consumers can either get a modem with, or without, the built-in telephony circuitry. So: coax cable goes in, and Ethernet and, optionally, analog telephone go out.
This VoIP function is not configurable by the end user customer, and the credentials (SIP user ID and password) are not given out under any circumstances. The customer simply plugs a telephone cord (RJ-11) into the jack in the back of the modem. The service is higher-quality than typical VoIP, because the IP traffic flows over Comcast's own, managed private IP network, to their own telephone switches (Comcast, unlike most commodity SIP VoIP ITSPs, is a Competitive Local Exchange Carrier with their own switches on the PSTN). Other cable companies like Time Warner offer similar services, and are also US CLECs.
So, bottom line: Sharad can either get telephone service from Comcast, or from an OBi plugged into the home network, or both. If Sharad wanted to move the telephone number from Comcast to some ITSP or back again, it would just be a standard number port.