integrate skype chat to asp.net webform -- 2

I have my own user in my asp.net webform website, need discussion group or chatting group like skype itself have all chatting function with the ability to add my website user to it.
you will create:
- group discussion like skype.
- can send file and image to the group
- real time update discussion when user post in group
- the date and time like skype
- seen by user
- no need to call & video function
- the backend must be sql server
- the ability to create group.
- no need to create user system because when you finish I will add my own user to the groups.
- the design look like skype.