An interesting point came up this week while in a discussion about using the same SIP domain when doing interop between OCS and Tandberg, it can be a bad idea in a large environments. This is of course related to using the Tandberg VCS. If you are registering Tandberg endpoints directly to OCS this is not an issue. When you start looking at the configuration of OCS for VCS interop you will understand why this has the potential to be an issue.
When you add a static route, as I have like in my screen shot, this is a blanket static route that has no filtering etc so when I send an invite with the domain VCS.domain it goes to the intended VCS specified in the IP address portion. Now if this domain is the same as my OCS domain, guess what, every invite generated by OCS has the potential to get sent to the VCS and not just to the intended system registered to OCS. In a small environment this is not such a problem and the VCS will work just fine but in a larger environment this could create a significant load on the VCS. I have not tested for this behavior myself but it certainly makes sense that this would indeed happen.
This also brings up another couple of points. When dealing with larger environment, rarely are the VTC and OCS team the same group of people. So it makes good sense to have separation virtually between the two environments using different SIP domains. Although this doesn’t quite fit in the UC model of unifying your environment this does ease things like troubleshooting and help create a demarcation point. You may think I am crazy saying that the same organization requires a demarcation point between teams but it’s an unfortunate reality. I have seen this quite a few times now in organization where they want to deploy UC but instead of the telecom, VTC and collaboration teams coming together to work jointly on a project they create a third silo for UC and another team is born. I have heard a telecom manager say, “You have to talk to our UC guy we (telecom) don’t deal with that stuff”.
So anyway, till next week.