Ok, so I'm working my way thru' Brian Johnston's book: "SIP"... It's GREAT for learning the protocol, but less-so for the basic topology, and how that relates to real-world implementations.

But I still have a couple of unanswered questions: I've just configured a 2820Vn, and added a Draytel account to the VoIP config.

I still don't understand, though: Can I have IP phones on the LAN side - I'm thinking not; I guess ALL VoIP traffic (apart from Skype) MUST be terminated at the router, and not with a SIP gatekeeper, like asterisk.

OK, second question: does anyone know of a FXO/FXS converter?? I want to connect a DECT exchange to the router, but both have FXS ports...
[ unless it is possible to trombone calls FROM VoIP to PSTN port?]

Thanks!

Yes, you can have SIP phones...the best way to do this depends on what they're talking to...e.g. your own remote server, a public service etc. You may need to use an external STUN server... but it may work.

What do you mean by a DECT exchange?

Thanks for the reply...

Err, the DECT exchange is a small box (remarkably small!) that accepts TWO analog lines IN, has TWO analog lines OUT, and will accept upto 8 - I think - DECT extensions.

The box does all the usual CFWD etc., and has the facility of blocking certain calls to/from extensions. It's FANTASTIC - was made by Siemens (badged BT). Haven't seen anything like it since.

I am thinking of running an asterisk server here... but SIP is new to me, and I'm still working thru' the protocol section of the SIP book, not got to the end user experience/implementation yet!!

Tks,

Simon R.

Oh, RE DECT exchange, for the purposes here, the DECT is irrelevant..it's just an exchange/PBX, and yes, you'd need FXO ports to connect...and none of the current routers support that (apart from Vigor 3300V) and the forthcoming Vigor 3510 but they've both 'big'.

OK, thought that was the case. I have a CISCO box here too; I might press that into service instead.

However, is it possible to trombone incoming VoIP calls OUT onto the analog line port??