[Serdev] Concept for a SIP cluster implementation

[Jan Janak]

On 29-09-2005 14:37, Klaus Darilion wrote:
> Jan Janak wrote:
> >On 27-09-2005 17:48, Klaus Darilion wrote:
> >
> >>Andreas Granig wrote:
> >>
> >>>Klaus Darilion wrote:
> >>>
> >>>
> >>>>So, we just have to make ser call-stateful first :-)
> >>>
> >>>
> >>>Yes. Any volunteers? ;o)
> >>>
> >>>
> >>>>>I'd say it's much easier to handle if the outbound proxy equals the 
> >>>>>registrar from the UACs point of view. So the UAC always sends all 
> >>>>>requests to the same edge proxy, which then splits up REGISTERs from 
> >>>>>other requests and forwards them to the appropriate server.
> >>>>
> >>>>
> >>>>
> >>>>Of course it would be much easier. How will you handle load blalancing 
> >>>>between the edge proxies? SRV? If you use SRV, the clients are free 
> >>>>send the request to whatever edge proxy. RFC 3263 says to use SRV 
> >>>>lookup for each transaction.
> >>>
> >>>
> >>>I don't want to use SRV, not only because of the NAT problem but also 
> >>>because most of the SRV implementations in UACs I've seen so far are 
> >>>broken, if implemented at all.
> >>>
> >>>So each edge proxy will be set up with a hot-standby proxy for IP 
> >>>failover, so there's no need for a failover mechanism in the UAC (to be 
> >>>as much independent from it as possible).
> >>>
> >>>If the first edge proxy pair (say sip1.my.domain) get's to a limit 
> >>>regarding ressources, you can add a second pair and propagate the new 
> >>>hostname (sip2.my.domain) to new customers.
> >>
> >>Thus, you solve the problem by provisioning. Btw: Openwengo (cross 
> >>plattform SIP phone) fetches all the SIP provisioning from the service 
> >>provider using https. Thus, it would be easy to change SIP configuration 
> >>and host certain accounts on certain SIP proxies. I like this.
> >
> >
> >  I don't like it because:
> >
> >  - People should be allowed to use any SIP UA as long as it is RFC3261
> >    compliant. And there never will be single widely accepted standard
> >    for provisioning.
> 
> Yes they should, but I really like the user experience - it is as easy 
> as installing Skype.

  Having common configuration makes this possible. You can have a
  preconfigured ua which will work immediately after downloading. Yet
  you can allow people use other phones/UAs if they prefer.

> >  - Doing central provisioning on a large scale is difficult,
> >    especially in heterogenous environment.
> 
> But I think it is worth the trouble as you save lots of support requests 
> from customers.

  Support requests will be there anyway, troubles with NATs, problems
  with the service, accounting, billing (if any) and other stuff.

    Jan.