Topic Last Modified: 2010-11-08

Unlike Microsoft Office Communications Server 2007 R2, Microsoft Lync Server 2010 communications software supports placing Access, web Conferencing, and A/V Edge external interfaces behind a router or firewall that performs network address translation (NAT) for both single and scaled consolidated Edge Server topologies.

Using NAT for all Edge external interfaces requires the use of DNS load balancing. In turn, using Domain Name System (DNS) load balancing allows you to reduce the number of public IP address per Edge Server in an Edge pool as described in the following list:

  • Lync Server 2010 Scaled Consolidated Edge (DNS load balanced)   Requires three public IP addresses for each Edge Server in an Edge pool.

  • Lync Server 2010 Scaled Consolidated Edge (hardware load balanced)   Requires three public IP address for load balancer virtual IP addresses (one time requirement that does not increment as more Edge Servers are added to the pool) plus three public IP addresses per Edge Server in a pool.

IP Address Requirements for Scaled Consolidated Edge

Number of Edge Servers per pool Number of required IP addresses Lync Server 2010 (DNS load balanced) Number of required IP addresses Lync Server 2010 (hardware load balanced)

2

6

3 (1 per VIP) + 6

3

9

3 (1 per VIP) + 9

4

12

3 (1 per VIP) + 12

5

15

3 (1 per VIP) + 15