How instant messaging works? Write the steps involved in this process?

The Instant Messaging services available permit us to manage a list of people (contacts) that we interact along with regularly. We can send instant messages to any of the contacts within our list as long as that contact is online. Subsequent steps are included in IM working:

1. User commences the IM client.
2. IM client finds the IM server & logs in.
3. It launches communication info (IP address, etc) to the IM server.
4. IM server searches user's contacts & sends him/her the communication info.
5. IM server also notifies the contacts which the user is online; sends his/her communication info to them.
6. The user's & the contact's IM clients are prepared to communicate directly (P2P).
7. As new contact has come online, IM server informs them about the user being online and many more.
8. Multiple, real-time chat are possible.
9. While the user logs-off, his/her IM client informs the IM server.
10. IM servers wipes away the temporary file and inform the user's contact's about his/her ‘offline' status.