So you want to set up OCS to work remotely. you read the documentation and try to decide how you want to deploy the edge servers so you can have remote access. There appears to be a lot of confusion about what is needed and how it all works. so let me see if I can explain a little better.
in a small deployment that wants voice video, live meeting, IM presence to have remote access. here is what you need and what it does.
- consolidated edge (this has the Access Edge, Web Conferencing Edge, and A. V edge installed on the same box)
- ISA Server for Address book download, Group Expansion while remote, and Live meeting Content Download.
Access Edge, Web conferencing edge, AV edge, all consolidated on the same box. So you can have all 3 roles loaded on the same box but that brings some challenges that we will discuss shortly.
So what does each server and server role do at the edge. Now remember I am not trying to be extremely technical and my description may be a little off but the general traffic flow is correct and the general use of each server is correct
Access edge proxy's Call Control traffic back to the OCS Front end servers. it also proxies IM and presence traffic from remote users. So When a user is remote or federated all im and presence.nse traffic proxy's through the access edge no other server is involved in the DMZ.
Web conferencing Edge server is a proxy for live meeting traffic to the conferencing focus which is on the OCS front end server in most cases. However the initial setup of the live meeting session is initiated through the access edge. during the initial setup of the conference information is passed about the web URI for the live meeting server to the client so it can find the web conferencing edge server. during this same session initiation the web url to the ISA server for content download is passed to the client as well.
AV edge role is used for Voice and Video proxy so that a user that calls a remote user from inside will initiate the call. which will take advantage of the access edge to establish call control. from this, call control information is passed that tells both clients (the one inside the LAN and the one remote) to send all audio and video traffic through the AV edge. So what this means is all clients in the LAN need to be able to send traffic to the AV edge. an interesting note is that when a call is initiated internally then the call is peer to peer for the voice and video. When it is remote the video and voice must hit the AV edge. Also when a conference call is established a different path is followed. in a conference call all Audio, video is sent to the front end server so it can be mixed and sent back out.
ISA server
used to proxy the location of he Address book download files, Group expansion files, and finally live meeting content. So will live meeting work with out this in place and will MOC work with out it. Yes it will however for MOC you will not recieve new address book downloads while being remote. And Group expansion may have some problems but the client still works.
As far as live meeting this depends on what functionality you need. this is where any uploaded files would be located so if you want to upload PowerPoints for presentations then this is needed. also if you want to post handouts then it is also a needed resource. Some people suggest just opening up port 443 direct to the front end server but this is not supported not recommended and VERY Risky.
The diagram below shows the three roles on separate servers for simplicity I have left the ISA server out for the time being this will be discussed later. and this is only showing a remote user to internal user. I know my picture is not great. but hey I never claimed to be an artist or even a master at Visio.
