After a user and an agent connect and a co-browsing session begins, several things start synchronizing.
One of the advantages of the approach shown in the schematic is that it allows for co-browsing to start at any time. For example, a user can initiate a co-browsing session while in the middle of filling out a long form. This approach also eliminates the need to worry about cookies and session timeouts on the agent side.
The following diagram illustrates the detailed communication between the parties mentioned above.