[sr-dev] Migration of Open IMS Core to sip-router

[Dragos Vingarzan]

Hi Daniel,

On Thu, Jul 23, 2009 at 9:00 PM, Daniel-Constantin Mierla 
<miconda at gmail.com <mailto:miconda at gmail.com>> wrote:

    quite a bunch of work, I would say. Can cdp be used for generic
    diameter AAA or is specific for ims?


No, the CDiameterPeer module is not specific and it can be used for 
anything that talks Diameter. The only IMS specific parts are a bunch of 
constants defined for the IMS interfaces in a header file, but of course 
there is space for other applications, which are of course welcome to it.

The cdp is a bit of a "server" itself that is forked from ser and can 
benefit from all the advantages that a ser process has. But it has it's 
own timer, workers, etc processes. The advantage of this is that it is 
quite easy (and we actually do provide an example here: 
http://svn.berlios.de/wsvn/openimscore/CDiameterPeer/trunk/#_CDiameterPeer_trunk_ 
)  to get a standalone Diameter node on the same platform. This is 
useful for implementing the other ends of the AAA communication when you 
like the ser memory, locking, etc routines ;-) but don't need the SIP 
related stuff.

I have quite a high confidence in the stability of this module as we 
seldomly had issues with it.  On the things to improve would be though:
* replace the sempahores with something better - they tend to accumulate 
over crashes of ser
* merge a branch that adds support for the authentication state machine 
and add the charging state machine - although I don't know if anyone 
would actually use this part and it would maybe just be overkill.

    IIRC, openser imported the ratelimit from openimscore, can you check
    if includes the features you have?
    http://sip-router.org/docbook/sip-router/branch/master/modules_k/ratelimit/ratelimit.html

Right, now I remember. So then one less thing to worry about. Sorry, I 
was only monitoring the ser tree.

         * Core - support for emergency URI,


    What is this exactly? Any reference to ietf/itu specs?

I am not really sure myself as somebody else did the implementation. But 
all the specs should be listed here: 
http://www.openimscore.org/emergency . And even for us this is still 
partly a branch with work in progress. The thing was that ser was even 
crashing when it got some of these, so in any case, even if not used, it 
would be a good patch.

I'll have to do a diff and find out what was exactly changes as there 
were to many things in the last 3-4 years. And we probably have some 
garbage through that. I'll send the patch after some cleanup.
 

        - sip-router_modules_s_dialog.diff - just some typos in logging

    This can be applied right away. I do not know who is in charge of
    the SER dialog module, if no one volunteers for it and you want to
    jump in, send me your ssh key and desired uername for git account.

Will do shortly. Will still have to get up to speed with git before 
pushing anything though.


        - sip-router_pt.diff
         - added a drop_my_process() function - in the cdp module
        (Diameter) we do have dynamic processes, which fork and exit
        distinctly from the ser ones, so we need this to clean-up.
        Without it, such usages would not be possible as the process
        table would fill and then new forks would be denied
         - I have commented the pt.c
        <mailbox:///root/private/_mail/Mail/common/Sent?number=587016624#pt.c>
        line 210. I am not sure if this is a bug or I just used the
        fork_process wrongly, but my process which was forked from a
        mod_init() not a mod_child_init() opens some sockets, which are
        mistakenly closed on fork_process() by the close_extra_socks(),
        which uses the pt[].unix_sock values from other processes, which
        overlap. So please advise on what would the best way be to still
        allow for the forked processes to open some sockets without them
        being closed on fork.


    I am not yet familiar with the new way SER manages the process
    table. Andrei, Jan or other ser developer may have more insights and
    guide here.

Partly the new process table management was sparked also by me, from the 
same requirements as now. Unfortunately for the first part not all of my 
patch made it and the other part was actually greatly improved by 
Andrei. If the case is that it won't be accepted that a process can 
dynamically terminate, then I'll have to redesign cdp. It's not a huge 
deal, but I'd rather not as it will just complicate things and I think 
that the process drop is not such a big deal anyway.

For the 2nd part, this was added later and I'm not sure if I did 
something wrong and the fork should've been done differently. But it 
looks like a potential bug anyway.


    I was looking to build such summary for kamailio, since current
    version is hard to track and creates quite big logs, which slows
    down the shut down. Can you create a new patch against sip-router
    core and attach to tracker:
    http://sip-router.org/tracker/

Will do. I also added to our ser_ims some clean-up code that frees-up a 
lot of the core's memory on shutdown. Unfortunately I got stuck at the 
fixed parameters, which you can't really make sense of in the core in 
order to free them. So I guess there's need for some "unfix" functions 
in the modules.
 
Cheers,
-Dragos


-- 
Best Regards,
Dragos Vingarzan