In my opinion "teleconversation" is business jargon, I've never heard anyone say it in normal conversation. I think you should avoid it.
It isn't clear to me whether the problem is in the project web system, or you are using the project web system to resolve a problem somewhere else. However, you will both know what the situation is and keeping the "on" covers both cases.
With reference to our telephone conversation today, it is better for you to come over to our office to resolve the problem on the project web system.
Please bring your laptop to the next meeting at xxxx office.
Student or Learner