[SR-Users] Measuring subscriber latency

[Olle E. Johansson]

On 29 Apr 2015, at 10:04, Daniel-Constantin Mierla <miconda at gmail.com> wrote:

> Hello,
> 
> On 28/04/15 20:42, Jon Bonilla (Manwe) wrote:
>> Hi all
>> 
>> I'm replacing an Asterisk based system with a kamailio based one. One of the
>> features the legacy system has is showing the subscriber the latency obtained
>> from the qualify option of sip.conf
>> 
>> Now, I'd like to measure the latency but I'm not sure how to do it. AFAIK
>> nathelper module sends the OPTIONS keepalive messages stateless mode and
>> there's no information there. 
>> 
>> I was thinking on triggering a route send_options via the timer module, save
>> the timestamp of the relay and the timestamp of the response in onreply_route
>> but it doesn't look elegant. Creating my own daemon in an external server and
>> reading the info from the location module seems to be another option.
>> 
>> I guess I'm not the first one with this need so I wonder if there's an already
>> existing solution or an elegant way of dealing with it. 
>> 
>> 
>> any ideas?
>> 
> it looks like you are the first wanting this, or at least the first that
> has expressed it.
As Jon said, this is a feature that has been in Asterisk for a very long time and 
we need in Kamailio. I think many of us has looked for it, but never mailed about
it since we still have Asterisk in there. Since Kamailio has grown so much and
we now can build Asterisk-free solutions, I think this would be a valuable feature
both for dispatcher and for usrloc.

/O
> 
> It might not be hard to code it in c, it will require to extend the
> usrloc structure to have with two timestamps, one to be set when sending
> the options and one when receiving the reply. At this moment there is
> only one timestamp when the reply is received, see the function
> ul_refresh_keepalive() from usrloc, the field in ucontact_t structure is
> last_keepalive. So half is done more or less.
> 
> You can open a feature request on tracker and probably will get into
> 4.4. The development for 4.3 is frozen.
> 
> Cheers,
> Daniel
> 
> -- 
> Daniel-Constantin Mierla
> http://twitter.com/#!/miconda - http://www.linkedin.com/in/miconda
> Kamailio World Conference, May 27-29, 2015
> Berlin, Germany - http://www.kamailioworld.com
> 
> 
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