I've been experimenting with the code samples for CTI web services - more precisely OneXOpenAPISample (C#).

When subscribing to get events, a message is sent containing the session ID of the extension to subscribe to.
Now, if I want to monitor more than one phone, can I then send a request for each of them and receive them on the same connection, or will EACH of them need their own? It seems that when receiving we're checking if the message is for our session ID, so that gives me reason to hope that I can monitor several phones. I don't suppose I need to send a "stop" message? - when sending the REST delete request to /inyama/service/session I assume that session will die?

Also, I have to make sure: while the example is called "OneXOpenAPISample ", things seem to be only IP Office specific and not necessarily bound to a OneX. Will I need to care what the users have?

My understanding is that you would either need a connection per monitored device, OR, you'll need what they refer to as an "Application User". I'm basing this off of the "Avaya IPOffice CTI Web Services Programming Guide-11_0.pdf" file, page 18:

"An Application User can invoke CTI Web Services on behalf of all the Device users. It also receives the events for all the Device users."