I want to customize my ejabberd chat server for following functionality.
- Group Chat
- Broad Casting Messages
- user logged in from 2 clients (as in web.whatsapp.com)
What config changes do I require for the same?
Ejabberd supports all the functionality you have mentioned.
1) Group Chat - The server should support XEP-0045 for Multi User Chat. Ejabberd supports that with the module mod_muc module. You can read the mod_muc docs for configuration
2) Broad Casting Messages - The server should support XEP-0033 for Extended Stanza Messaging. Ejabberd supports this with mod_multicast module.
3) For user logging in through 2 clients, please read this https://github.com/processone/ejabberd/issues/72