Hi there,
Has anybody experience about running and OSS System in enterprise level?
And do you have any idea about it?
For example for an ISP who is running users more than 20K or 30K, there
must be some good solutions to integrate all systems like:
Radius, Billing Systems and CRM
For example after searching and asking friends I have some ideas about
Radius to use: radiator
Is there anybody who has analyse such a systems before in his ISP? Need
sharing here 
Thanks
We did this a few years ago and ended up writing the while thing ourselves. This included billing, subscriber management etc etc.
We integrates to salesforce.com for the internal front end and the user facing stuff we did ourselves.
It was a big project and took a team of six about six months. But we ended up with a perfect solution that did exactly what we needed and it was pretty good.
It handled within the order of users you mention, but we designed to 100k users.
We used radiator (highly recommended) with openldap back end. Multiple load balanced servers etc etc.
The worst thing we did was to build our own mail system. Not that it was an issue, it never went wrong, but these days I'd just send people to gmail or something.
Dear Leigh,
Thanks for you answer, So you recommend radiator?
What about analyses, you know always thinking about billing systems with
staffs who does not have any idea about backend is hard ...
You always have problems with operators and they make lots of exceptions,
Is'nt it?
And if you have time would you please tell me more about your load
balancers?
I am really confused really with designing and analysing this project 
Thanks
Hi there again,
I think Leigh is not available this week, anybody else idea about such a
system?
Which loadbalancer is good to use? LVS or hardware one? or radius as a
proxy?
How database must be placed? How radius servers talk to DB?
And which radius server you suggest? Radiator?
Thanks
My personal opinion has been that we have seen great success in large environments with FreeRadius and using radrelay for mysql synchronization then an OpenLDAP-backend. We used FreeBSD/CARP and/or FreeVRRPd for failover but this can be accomplished in other methods.
FreeRadius has a built-in CLUSTERIP module which allows clustering/load-balancing/failover or you could AnyCast the systems for redundancy.
As for load balancing other Radius servers which may not have it built in - I would say a hardware solution is usually great because you get support, etc. However, if you don't need the support then there are a ton of options available. You could go as far as load balancing it with LVS (which I personally do not like but MANY do :)) or software load balancers like pen/pound/haproxy.
Best of luck!
Hi there again,
About this solution can anybody help about the best partition layout for
these machines?
For such a OSS system we need these 4 machine and having best partition
layout for them is important for example maybe we need a big /var/log for
Radius Server and etc.
   1. Load Balancer (ipvs)
   2. Radius Server (radiator/freeradius)
   3. Database Server (mysqld)
   4. Web Server for Billing (apache2)
Thanks