So the time has come for official Lync mobile (MCX) support to be unleashed (well kinda, technically its in two days time) & it looks like there needs to be some architectural changes to make it all work. It’s nothing too challenging but there are one or two design decisions that need to be made & at first glance the official documentation is a bit complex… Hopefully I’ve managed to simplify things here & cover over the basic install in a step-by-step way.

Update – Part 2, Part 3, Part 4

My environment is as follows: a Single Enterprise Edition Front-End server, a single Edge Server in the DMZ and an ISA server acting as a proxy. Because this is a very small scale deployment there is no Director in use…

Overview of changes

  • Add two new DNS records – one internal, one external
    • Either A records or C-Names
  • Patch everything to Lync RTM CU4
  • Define the “Internal ports” used for mobile clients
  • Install mobility bits on Front-Ends & Directors
    • Enable Dynamic compression in IIS
  • Re-request certificates to support new mobile DNS names
  • Configure your reverse proxy
  • Configure push notifications
  • Test! (Kinda)


Internal DNS

Add a new record to your internal DNS for “Lyncdiscoverinternal.<sipdomain>

This should either be a Cname that resolves to the internal FQDN of your Pool or Director server, or an A record pointing directly to the IP of your director or Pool (NLB IP if your using more than one enterprise server).

I’m going to use an A record to reduce the hops needed for name resolution & because I’m using an internal certificate server so it’s not any hardship (or expense) for me to generate a new certificate containing the new mobility record.

Open your DNS server up & expand out the zone for your SIP domain (your probably using split DNS as this is liekly to be your internet facing DNS name rather than your internal domain name).


Here is my discovery record used by Lync client that resolves to in turn resolves to That’s the IP we want to use for our new record


Create the new record


External DNS

Find the external IP of your reverse proxy by opening Topology Builder and going to the top level and looking at what you have set as your meeting URL


Chances are that whatever IP you have this resolving to will be the IP of your reverse proxy (if it’s not then you obviously know what your doing so can figure it out 😉 )


Create your new record

clip_image006Continue to Part 2