How many Big-IP appliances for Microsoft Office Communicator across a campus LAN?

Every time I get stuck with the F5 product portfolio I post a query and the forums come up trumps. Who is up for the challenge this time?

 

 

I have client who is looking to implement Microsoft Office Communications Server 2007 R2 for voice, video, instant messaging and conferencing across the entire campus. This campus comprises of some twenty buildings in one geographical location but has four physical datacenters. Unfortunately details of the LAN are limited but I believe they have a relatively new Cisco 4500 or 6500 series chassis in each datacenter with private fibre connectivity between the datacenters. Sorry but I don't have any vlan information but can only assume they have followed best practise and applied at least vlan traffic seperation by building etc.

 

 

My customer would wish to put in a high availability Microsoft Office Communications Server solution with servers in the pool being split across at least two of the datacenters. My first port of call was the design guides but they don't answer my question unfortunately as it assumes all servers are located in one location.

 

 

If I place two Microsoft consolidated front end servers in each datacenter and wish to use BIG-IP for load balancing in front of all of these Microsoft servers what would the design look like? Am I correct in thinking it is possible that I can place a single LTM in each datacenter and then have both BIG-IP appliances in active/active configuration with a network hearbeat across a dedicated vlan/LAN setup? Thus servicing the four Microsoft front-end servers split across two datacenters?

 

 

Hope my query makes sense and I'm not letting the F5 community down asking silly questions!!! Keep up the good work. Many Thanks....