text conferencing

Situation:

I have a week to find a low-cost solution for hosting a presentation where one individual holds a discussion via video cast.

(Gotta love HR) Approximately 600 users can add input/ask questions via text chat.

Network constraints: MPLS network across 4 websites (100Mb cox Ethernet) internet pipe with 300 users in one site, 110 from another site (90Mb), 140 from another site and 10 people in the other (45Mb).

If anyone has a solution for a low-cost, LAN-based Video and Text conferencing software/appliance, I'd appreciate some input.

Toronto, ON (PRESS RELEASE - April 24, 2009) - Expressway Video, a provider of streaming media hosting, releases the Flexchat.

Flexchat is a video, audio and real time text conferencing software for new or existing internet businesses.