Is there any client user limitation on server?

Is there any client user limitation on server???

How many users can connect to server at the same time?

That is entirely dependent on your server’s RAM, and how much is allocated to openfire. if in the thousands you may nee to cluster the server

I am using Windows2003 server. I have 75GB harddisk and 4 GB ram in my server.

I can see under Server Manager tab In database property It shows MINIMUM CONNECTION- 3 and MAXIMUM CONNECTION- 25. what does it mean?

I have 70 user. can they connect to server at the same time ?

These are database connections, not users. I don’t know all the details, but these connections are between Openfire and its database when it stores some information in the database. At some point database connections can have influence on user connections number, but this number has to be huge (tens of thousands of users or a very heavy traffic of packets between users and server). 70 users are ok and probably you can have a lot more. But that depends on what this server is doing besides serving Openfire.

with a mere 70 users you should have no problem running openfire. Just be careful of using the monitoring plugin and logging the chats. It will bloat the database fast. I recommend a dedicated NIC for openfire if you are running other functions on the server. It does generate a lot of network chatter for presence and other functions. Also even with your small user base do not use the embedded database. Use mysql or some other external db.