Re: [Sip] [Sipping] INVITE dialogs

[Pamela Zave <pamelazave at gmail.com>]

The count of new races is rather arbitrary, of course, but some are  
serious ones requiring significant programming effort to work  
around.  As Paul says, removing my simplifying assumptions can only  
make the problem worse, not better.

I realize that it is not easy for someone new to delve into the model  
quickly.  I propose to extract a few cases that I find interesting,  
check them with experts for validity to avoid wasting everyone's  
time,  and post a readable summary.  Then everyone should be able to  
assess the substance.

I am about to leave for a week of vacation, so ETA is the first week  
of November.

I hope this is helpful.
Cheers,
Pamela


On Oct 24, 2008, at 1:32 PM, Paul Kyzivat wrote:

> Pamela,
>
> Will you perchance be attending IETF73 in Minneapolis this Nov?
>
> There is some interest in having you talk about the race conditions  
> you say you have found.
>
> 	Thanks,
> 	Paul
>
> Pamela Zave wrote:
> > At the suggestion of Paul Kyzivat and Dale Worley, I compared
> > draft-ietf-sipping-race-examples-06.txt
> > to the basic Spin model of INVITE dialogs at
> > http://www.research.att.com/~pamela/sip.html.
> > Of the 13 race conditions in the sipping draft, 6 of them are out  
> > of the scope of the Spin model.  Most commonly, this is because  
> > they include retransmission of a lost message.  There are no  
> > transmission failures in the Spin model.
> > Of the remaining 7, all of them are in the Spin model, handled the  
> > same way.
> > In addition, the Spin model shows 42 additional race conditions.   
> > This count is subject to a lot of interpretation, so I estimate a  
> > possible error of about 20%.
> > Pamela Zave
> > _______________________________________________
> > Sipping mailing list  https://www.ietf.org/mailman/listinfo/sipping
> > This list is for NEW development of the application of SIP
> > Use sip-implementors at cs.columbia.edu for questions on current sip
> > Use sip at ietf.org for new developments of core SIP

_______________________________________________
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