[asterisk-users] Re: How to separate outgoing extens from the contexts from sip.conf?

[Larry Alkoff]

Problem solved and posted below.
I may have found out at lease two things that may help others.

Especial thanks to Eric "ManPower", Benny Amorsen, Luan LIU, Paul Hales,
Pavel Jezek and a _lot_ of research on the web.

The problem was separating the contexts for incoming VOIP calls
from the outgoing trunks to eliminate the possibility of an outside 
caller being able to make calls (international, 900 numbers etc)
on my dime.

This _might_ be a new wrinkle but I believe it should apply to most 
setups that use a 'gateway' SIP trunk to access their ISP.

My setup has gateway SIP trunks to my provider Telasip.com and my
Sipura SPA-3000 for PSTN calls.

Sipura is easy to separate since the Voxilla Sipura setup wizard setup 
separate inbound FXO to CO and outbound trunks FXS from POTS phones.

Most ISP trunks would be expected to be a Peer and thus have no context.
Telasip instructs their customers to setup the gateway as a Friend with 
a corresponding context=telasip-incoming line in sip.conf.

This makes it easy to process all incoming calls from Telasip completely 
separate from dialed calls which are handled separately in the sip 
phones context=sip-outgoing.

Since my system is for a single family, all users have full access to 
long distance (no teenagers!) although it would be easy to have classes 
of sip phones with different privileges.

Telasip told me that it was necessary to have a line in their gateway 
sip.conf entry that 'insecure=very'.  I have found Telasip to be a most 
excellent provider with great support.


The other thing is that I found out on the voip-info wiki that a 
[default] context in extensions.conf is treated different from other 
contexts.  If there is no context=something line in the [general] 
sip.conf, then all calls that cannot find an extension to goto will come 
into [default] or [something] if such a line exists in sip.conf 
[general].  I didn't know _that_.

Voip-info warns against putting any lines in [default] that might allow 
a caller to call out in that context.

In my case, anyone who manages to get into [default] goes direct to 
voicemail and, when they finish with that, get either a hangup or 
congestion to dispose of the call.  Of course, if they wish to leave a 
vm I'll consider it but I expect that few will.  There is nothing else 
in [default].

Finally about 900 calls.  My 10/11 dial plan lines exclude 900 calls.
My wife and I don't need them any more <vbg>

Hope this information will be helpful to someone else.

Larry

-- 
Larry Alkoff N2LA - Austin TX
Using Thunderbird on Linux