[GnomeMeeting-list] SIP with Gnomemeeting and Phone to PC!

[Sam Lown <sam pagmas com>]

Hi,

For those interested, there is a way to get a SIP user to call any H.323
device - Asterisk.

Firstly, I'll explain why this is useful. There is a service in the UK
that gives you a Phone-to-PC gateway, but only via SIP. I am actually in
the process of getting them to test H.323 with me, so with a bit of luck
that will work soon and this e-mail will be redundant.... We're going to
see SIP in GnomeMeeting soon anyway, aren't we? ;-)

The address is: http://www.speak2world.com, I discovered them totally by
accident on a link in ebay.co.uk of all places! Their site basically
says:

"Get a FREE UK 0870 [+44870] Number for your Internet [SIP] Phone today
!!!"

And yes, you can call these numbers internationally. It works very well
indeed with my setup... and it is completely free! (the callee pays for
the cost of the call at national call rates) 

You might be assuming at this point that you need a quicknet card or
something similar, NO!!! Their service is based on an Asterisk server
and uses GSM!!! FANTASTIC!

Heres how I managed to set up a SIP to H323 gateway using Asterisk (not
for the weak of heart):

 - Compile Asterisk with the chan_h323 module - you'll need to get and
compile all the OpenH323 and pwlib stuff (www.openh323.org) - see the
asterisk pages (www.asterisk.org) for more info.
 - Work out how on earth to use and configure Asterisk - RTFM
 - Add the following lines to the default context of the extensions.conf
file: 

exten => s,1,Dial(H323/<ip of gnomemeeting machine>|30|r)
exten => s,2,Hangup

Where r tells the asterisk to route the call, and leave the gnomemeeting
user to answer. (This way the callee only pays when you are connected)

Of course, if correctly set up, it could also operate for NAT traversal
with both H.323 and SIP; asterisk even converts compression algorithms,
so a SIP call using GSM is converted automagically to G.711 on my
ethernet phone.

I'll try and get round to setting up a web page with more details and
example configs, unless some other site already exists!?

As I said, hopefully they'll add H323 support to their servers.

Hope this helps, or at least inspires someone :-)

Cheers,

sam




BTW: I am in no way associated with speak2world and take no
responsibility if you manage to break your computer by following my
suggestions in this e-mail.
-- 
www.samlown.com