The Websense is already deployed in the network that will soon start to utilize OCS. I may not have made this clear, but that environment is a completely separate network than the OCS network. So all these users from that environment will be remote users to OCS.
I am aware of protocols for MSN, Yahoo, and AIM that are available with Websense, but I'm not sure how it will handle OCS protocols. I am assuming they will need to configure a custom protocol for OCS with the ports and transport it will utilize.
I'm not sure about the file attachments and UDP traffic. Websense is able to calculate the bandwidth of this traffic and can block file attachments over a certain size, but I don't know if that protocol is the same one OCS utilizes for file share. I also am not sure how it will treat secure IM.
I will need to ask the IT of that network how they have Websense deployed and I'll update with specifics once I receive a response. I don't believe ISA is their standard application firewall/reverse proxy.
Thank you-
Enjoy the 4th!
Jo