How do the two integrate? I assume it is a login over the network and not a physical connection?
There are many answers to this question since it is kinda vague. The two are integrated at many levels.
There isn't a physical connection between the hardware pieces, but the relationship relies on data and network conectivity.
The IEX server collects phone data from the CC6 server(s) for phone stats related to calls, handle time, various agent states, and in some cases real time input / output.
The CC6 install quite meets our expectations and has performed at or above our previous ASPECT install. As with any integration there are limitations / issues depending on the components. Since Nortel is a skills based system and ASPECT is not, the Nortel system was easier to integrate and maintain.
I'm sorry this isn't very specific, but the hardware/software integration - setup is better answered on the IEX web site, but as far as real life questions I can help, as I have worked with IEX and both ASPECT and Nortel installs.