[Users] Call not torn down when CANCEL sent before INVITE message is finished being processed

[Bogdan-Andrei Iancu]

Hi Klaus,

Klaus Darilion wrote:

> Bogdan-Andrei Iancu wrote:
>
>> Hi Klaus,
>>
>> that was a second idea :).
>>
>> actually you do not have to do anything special to keep the CANCEL in 
>> memory - it will be kept as transaction if you forward it statefully.
>> what I do not like in this approach is that for each INVITE you have 
>> to search for a potential previous CANCEL  - which is quite 
>> consuming... I would prefer an approach with minimum impact on the 
>> performance.
>
>
> Hi Bogdan!
>
> One one hand we care about fast transaction handling/matching, on the 
> other hand we have problem with external lookups which take a long 
> time (db, radius, DNS ...) compared to opensers internal processing.

I'm aware of these problems - the idea is to try to reduce their effect, 
depending of their specific.

>
> For example: 4 clients send an INVITE to a domain with a broken 
> delegation. Thus, all threads are busy doing DNS. Thus, a SIP proxy 
> which can handle 1000000000 requests per second is oversized in real 
> life scenarios, were the external processing is the bottleneck (unless 
> we start 1000000000 threads).

for DNS, for example - try to reduce the timeout on your DNS server; 
also we consider having DNS cache for OpenSER - some contribution ;)

>
> Of course I'm happy that openser peforms quite well, but in my 
> scenarios performance problems are always external. And I really would 
> like a working INVITE/CANCEL which deals with these problems.

I will keep this is mind (if not, please remind me) and I will try to 
fix it after the release ...in a way or another.

regards,
bogdan