[asterisk-users] Free sitting

[Gordon Henderson]

On Tue, 7 Aug 2007, Olivier wrote:

> 2007/8/7, Gordon Henderson <gordon+asterisk at drogon.net>:
>>
>> On Tue, 7 Aug 2007, Olivier wrote:
>>
>>> Gordon,
>>>
>>> What you described is exactly Follow-me feature : users are always
>> logged
>>> and can be reached somewhere.
>>
>> I've heard of some variants of this feature - that's the beauty (and
>> down-side!) of a programmable system - it's open to different people's
>> interpretations... (And why I think some of these features shouldn't be
>> hard-coded into the system when they are implementable in the dialplan or
>> AGI)
>>
>>> By the way, do you introduce special settings so that ringing tones are
>>> different ?
>>> Let me explain this :
>>>
>>> If Alice dials its extension and PIN code using Bob's hardphones, Bob
>> and
>>> Alice can both be called with the same phone.
>>> Is it possible to have different ringing for Alice and Bob's incoming
>> calls
>>> ?
>>
>> The simple answer is "I don't know"..
>>
>>> Maybe an SDP option inside INVITE SIP message would do the trick ?
>>> Maybe hardphone settings would read INVITE fields (Contact info ?) to
>>> segregate calls ?
>>
>> A simple way might be to change the caller-id on follow-me calls - change
>> the name part into the number and change the number into a special number
>> that the phone recognises as a separate ring-tone, but you lose
>> information here, and need a phone that can display both name and number
>> at the same time, and connect numbers to different ring-tones - then you
>> end up going down the route of requiring a certian phone for a certian
>> service - which might be acceptable to some people, but defeats the whole
>> generic "any SIP phone will do" type ideas.
>
>
> Could you elaborate ?
>
> I know some hardphone (eg Thomson ST2030) can set ring-tone according
> Caller's presence inside phone's directory.

The Grandstream GXP2000's can store 4 ring-tones. 3 of these can be 
matched to an incoming callerId, so for 3 different numbers you can have 3 
different ring tones, with everything else using the default ring tone.

Another option I've just thought of (after having a look at the config 
screen one one of my GXP2000s) might be to use a different account on each 
phone for the follow-me feature, so if you had extenstions 100 through 199 
which were real people, and extensions 200-299 mapped to the 2nd account 
on each phone, then ring that on a follow-me and assign that account on 
the phone with a different ring tone - that would preserve all caller-id 
information, but it would them depend on having phones with multiple 
account support.

So you "own" extension 123. You sit at the phone which is extension 150 
and dial in the follow-me codes. Someone dials your extension, 123, the 
system recognises you've got follow-me set, and diverts it to the 
follow-me extension plus 100 - ie. 250 which is the 2nd account on phone 
150 which then activates a different ring-tone... (and on the Grandstreams 
you'd need a different LED flash for the differnet account being rung)

More work to setup the system and phones, but ...

> In this case,  Asterisk would have to :
> - fake original caller-name and set it to "call for Alice",
> - replace original caller-id with Alice extension (eg 4111 instead of +44
> 812 41 54 66)
> so that  hardphone  gets  everything it needs to :
> - recognize from caller-id that the calls comes from Alice (though it's a
> call FOR Alice)
> - and then uses Alice ringing tone instead of Bob's tone.
>
> Is this roughly correct ?

Yes, but messy :)

> How many phones behaves like this ?

I'd suspect all phones which have multi-account support, so they could 
have at least one ring-tone per account.

The GXP2000's can match on 3 incoming numbers in addition to the default.

The Snom 300 I have appears to have 4 lines and 9 different ring tones you 
can assign to each line, as well as 4 categories of ring groups in the 
address book, so I guess the other models in the range have this, or more.

> As you said, it would be sad to loose SIP portability.
>
> It would be nice to use SIP protocol to drive such behaviour.

Indeed...

I think the 2-account system might be workable though, but more work to 
setup on the phone side of things...

And I like that enough to implement it for GXP2000 (And Snom customers, I 
think!) At least as an option, anyway.

Gordon