A direct conference using the Cisco Telephone System allows a maximum number of 4 simultaneous video/audio participants. Sharing Desktops is currently not possible.

Starting a conference using CISCO phones

You can initiate a conference via the telephone as follows:

To be able to call the first participant and to start a conversation, you must press the conference button on the phone.
To add a second participant to the conference, you need to type his/her number using the search function.
After entering the number, press the Conference button to add the participant and to start a conference. Repeat the process for a third participant.
If you want to add more than 4 (creator + 3 others) participants to a conference, you will get the following advice.