On of the features of the Communications Server product going all the way back to Live Communications Server 2005, is Public IM Connectivity (PIC). This feature allows you to setup connectivity between Communication Server and three of the largest public IM providers (Windows Live/MSN, AOL, and Yahoo).
You implement Lync, including the Access Edge server, and setup PIC to AOL, Windows Live and/or Yahoo. PIC is working fine with Windows Live and/or Yahoo, but you're seeing intermittent issues with AOL. Sometimes the IMs go through to the AOL users but seem to take a long time to actually go. IMs from AOL users to your Lync users seem to go through faster than from Lync to AOL, but sometimes they don't get through at all (the AOL user may get an "Unable to send IM (error 408)" on their clients..
This may be caused due to the Cipher Suite order used by the Windows OS on your Access Edge server when communicating with AOL's servers. Scott Oseychik posted a blog entry a couple years ago about this effecting OCS 2007 R2 on Windows 2008. This same issue also effects Lync 2010 whether its on Windows 2008 or Windows 2008 R2.
In order to resolve this, you need to change the Cipher Suite order used by Windows such that TLS RSA with RC4 128 MD5 is tried first.
In order to change the Cipher Suite order, do the following on your Access Edge server:
Please note, there are other possible things that may cause PIC issues between Lync and AOL (as well as Windows Live and/or Yahoo).
Just wanted to let everybody know that we need to follow the following article
in case you are using Windows 2008 R2 witt/without sp1. Since GP editor is not allowing more than 1023 characters. Wanted to save everybody's time :)
Awesome link. This was my problem and you nailed it!
Nice article, this helped us to resolve long term issue with federation between Lync and AOL.