NOTE: This article is in progress and may get additional data and corrections.
NOTE: Lync can do all the below federation without additional hardware, software or licenses cost from Lync perspective.
Which major unified communication solution connects and allows you to collaborate with the most people outside your organization? In many cases with no extra hardware?
Below are some of the UC solutions Lync Server 2013 allow you to collaborate with “out of box”:
* will soon be rolled into Skype
** Audio coming in 2013
*** Using AOL PIC; Okay, I know we’re stretching, but there IS connectivity!
4) IBM SameTime requires gateway from IBM to connect to other solutions: Click Here
Some Commercial “Federation” Solutions
Perhaps you disagree? If you have a UC solution you would nominate as the “most connected feel free to nominate via comments. (But please do include sources to support)
Skype 1/3 of Phone Call Traffic: