> -----Original Message-----
> From: Lawrence, Scott (BL60:9D30) 
> Sent: Monday, November 09, 2009 2:04 PM
> Suppose that you get this scenario:
> 
>   Phone A and B share line 123.
>   Everything is set up correctly.
>   Phone A seizes line 123, sets up a call.
>   Network is partitioned such that
>     Phone As call is unaffected.
>     Phone A is not reachable from the SAA server
> 
> if I understand the issue correctly, this is where the 
> problem occurs; the SAA will start getting timeouts trying to 
> contact Phone A to find out when the line is freed.
> 
> Supposing that SAA decides the line should be freed, what 
> happens when the network heals?  If in the mean time the SAA 
> has freed the line, it disagrees with A about whether or not 
> it A has it seized.  Worse - SAA may have since allowed B to 
> seize the line.
> 

If the network heals, SAA will learn from A's update that the appearance
is busy.  However, as you say, SAA may have allowed B to seize that
"appearance" of the line in the meantime - and then there would be two
calls on the same "appearance".  Add that to my general objections about
the whole appearance number thing.  It just doesn't work very well.

So, is it worth doing any of this special shortening of the SUBSCRIBE
time?  Without it, the light stays on until the set's registration
fails; it is then turned off (the appearance is freed).  Without it,
there is also a whole lot less messaging when calls are made, passed
around by hold, and released.

Carolyn
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