[asterisk-users] Newbie would like some planning advice.

[Gordon Henderson]

On Mon, 26 Feb 2007, Alan Chandler wrote:

> Ideally a DECT handset, which communicates with a basestation that
> either plugs into a LAN, or one of the computers would seem good and
> indeed the Philips VOIP1211 would seem to possibly fit the bill and be
> in a good price range.  Unfortunately, all I can find out about its
> interface capability is that it is "Skype compatible".  The same is
> true of most other handsets that I can find - they say they are Skype
> compatible without giving any more detail.

I'm playing with a pair of Siemens C460 DECT phones. The base stations 
have both a POTS line and a LAN connection. They aren't perfect in some 
respects, but are working very well.

The "Skype compatable" ones will likely have a USB connection. Avoid if 
possible as you'll likely never get drivers to use the keypads on the 
phones with anything other than they version of Skype they provide with 
the phone.

> I was thinking of setting up Asterisk on my Linux Server and providing a
> limited service to my family as a PBX. But this will only be cost
> effective if I do not have to make more than a few pounds investment in
> handsets.

The Siemens ones are more than "a few pounds". (www.provu.co.uk) So you 
have a choice - use a "soft phone" (XLite, idefisk, etc.) with a USB 
handset, or headset (headset is preferable IMO, *IF* your PC has decent 
sound hardware) or spend the £££ on decent phones....

> With that background, a few questions.
>
> 1.) If I keep everything at the SIP/RTP level, can I operate Asterisk on
> the server along with everything else.  Its a 1.7G Celeron, and the
> loading from the other services is around 5% to 10%.

Would be just fine for your applications.

> 2.) Can I make these so called "Skype Compatible" handsets work with
> Asterisk, or failing that are there any recommendations for
> alternatives which do work, but have the wireless capability described
> and don't cost a lot.

Most of the ones I've seen are simple USB soundcard/microphone devices, 
nothing more. The "hard" part is driving the keys on the phones. You don't 
need to though as the soft phones (eg. xlite, idefisk) have keypads built 
in, so you use the mouse. Downside of soft phones is that you need the PC 
to be turned on and running the soft phone application...

> 3.) Can Asterisk manage the NAT traversal that will be necessary for
> communication from handsets on the WAN and handsets on the LAN.

Port-forward 5060, 10,000 through 20,000 to the asterisk box inside your 
LAN, tell asterisk it's behind a NAT system (you need the appropriate 
runes of localnet, externip in the sip.conf file) and have the external 
phones use a STUN server.

Gordon