The load balancer performs the critical role of
delivering scalability and high availability across
multiple servers connected to a centralized database on
the Office Communications Server, Back-End Database
server.
Only one load
balancer is required, but you can optionally create two
logical load balancers--one for the front-end servers
and one for the Web Components Server--if you deploy
Enterprise Edition in an expanded configuration. If you
want to employ two logical load balancers, you can
configure two virtual IP (VIP)
addresses on one physical load balancer or you can
configure two separate physical load balancers. In
either case, you must create one load balancer FQDN for
the front-end servers to use and another load balancer
FQDN for the Web Components Server to use.
Note: You
don't need a Load Balancer if you have only one FE
server.
|
Required Ports on the Load Balancer Virtual IP
Address |
|
Port(s) Required |
Virtual IP (if you have more than one logical load
balancer)
|
Port Use |
|
5060 |
Load
balancer VIP used by the front-end server(s) |
SIP
communication |
|
5061 |
Load
balancer VIP used by the front-end server(s) |
SIP communication over
TLS |
|
135 |
Load
balancer VIP used by the front-end server(s) |
To move
users from a pool (a remote DCOM-based database operation); To enable
server-side allow and block functionality for users |
|
80 |
Both load
balancer VIPs |
Communication with the Address Book Server (ABS) |
|
443 |
Load
balancer VIP used by the front-end server(s) |
HTTPS
traffic to the pool URLs |
|
444 |
Load
balancer VIP used by the Web Components Server |
Communication between the focus (Office
Communications Server component that manages
conference state) and the conferencing servers |
|
Important links for the NLB |
Network Load Balancer technical overview
