[Asterisk-Users] using asterisk with iptel addreses

[Karl Brose]

Hi there.

Graham Turner wrote:

>was wondering if anyone could give us a run through an explanation of the
>wiki and other examples of connecting to iptel's sip express router using
>asterisk pbx so i can understand better the call processing  ..
>
>given the example i work from on john todd's www.loligo.com site ;
>
>exten => _3.,1,SetCallerID(${IPTELUSERID})
>exten => _3.,2,SetCIDname(${IPTELUSERNAME})
>exten => _3.,3,Dial(SIP/${EXTEN:1}@iptel)
>exten => _3.,4,Playback(invalid)
>exten => _3.,5,Hangup
>
>are the first two statements mandatory to connection to iptel.org ??
>  
>

No, they aren't..  When you use a peer definition to place a call, as 
you do here with the [iptel] section in sip.conf
and your given Dial command with the @iptel address, setting the caller 
id at this point is actually useless, as the username and fromuser 
options in [iptel] section will override these settings.
In addition, this example usage of SetCallerID and SetCIDname  is wrong 
anyhow,  It should either be just   SetCallerID("your name" 
<yournumber>), ie setting both name and number in one statement, our 
doing it in two statements, e.g.:
SetCIDname(yourname)
SetCIDnum(yournumber)
In all these statements you can substitute the literal name and number 
strings with symbols defined in extensions.conf,
as you have, ${IPTELUSERID) etc, so it's just a macro substitution 
within extensions.conf

>i understand the dial plan of any numbers prefixed by 3 are interpreted as
>iptel extensions, and that the third extension priority strips off the
>prefix
>
>presumably the call is then 'processed' by the [iptel] section of sip.conf
>and generates sip call with the credentials in this section as those passed
>to the iptel.org server ??
>  
>

Correct.

>how (iassuming they do) these relate in any way to the IPTELUSERID /
>IPTELUSERNAME variables defined in extensions.conf ??
>  
>
The parameters in [iptel] have no relation to these symbols and you 
can't use the symbols in sip.conf

>presumably (and i am using a 7940 sip device) i can dial an asterisk
>extension of targetiptelusername prefixed with 3 to call the sip user
>registered with
>
>qu. does the target iptel username need the iptel.org domain appended to it
>or is it somehow 'implied' by the above ??
>  
>
No, you just dial the extension number.  The SIP driver takes the domain 
portion of the SIP URI from the
host parameter in [iptel].

>another wiki example suggests the use of a 'fromdomain'  statement in an
>[iptel] section of sip.conf  ??
>
>  
>
The fromdomain parameter should specify the authentication domain or 
realm that the username (=destination extension) you specify belongs to. 
Without the fromdomain parameter, Asterisk has the habit of placing your 
raw IP address from which you're calling  into the From: SIP header, 
example:    From: "George Bush" <sip:1600 at 65.172.163.121>
instead of the domain that your exention (1600) belongs to 
(whitehouse.gov). The fromdomain parameter is sometimes needed to 
connect to certain proxyservers that require a caller to belong to their 
domain to call certain services.

Hope this helps