Importance of High Port Range (50,000 – 59,999) between two Edge Pool

We were working on building of second lync 2013 Edge Pool to achieve HA and Load balancing for our Lync infrastructure and came across with lots of funny and nice things. I cannot highlight all funny things here,But going to explain the most funniest part.

In our environment, we have two edge pool, one pool is for lync 2010 frond end pool media association and new edge pool is for lync 2013 media association. Environment has few mediation pool which is connected with lync 2010 edge server for media association.

If someone call from remote access to desk phone (connected Via Mediation server) using lync 2013 edge server it was getting failed. When we saw the lync traces and netstat logs it was showing that, lync 2013 edge servers and remote client is trying to reach 50k port ranges of Lync 2010 edge server (This is enterprise voice calls and going to use lync 2010 mediation which is associated with lync 2010 edge servers)

So we must have to open 50K port ranges for both of edge pool servers so client can connect and do the enterprise voice calling seamlessly. Below is the technet forum discussion which also helped us to understand more and taking decision to open this high port ranges

https://social.technet.microsoft.com/Forums/office/en-US/faf15263-8950-44e5-af6e-6eaf8b23f0b5/lync-2013-client-still-tries-to-connect-to-lync-edge-on-ports-5000059999?forum=lyncconferencing

Hope, it will help someone else J