What is a Connect?
A "Connect" is a time-based value that is defined under SETTINGS => YOUR ORGANIZATION => CALL SETTINGS.
The idea for a "Connect" is to show how many actual conversations have happened out of the the total number of calls made. By default it's set to any calls that are at least 2 minutes long.
Generally speaking, it shouldn't take 2 minutes to leave a voicemail, find out the prospect is not in yet, etc. However it's not a perfect metric in that sometimes a call will be longer than 2 minutes even though an actual conversation has not occurred (e.g. leaving a really long voicemail, bouncing around in a phone system, being put on hold for a long time, etc.).
There is also a Connect custom field in Salesforce on the Task object where you can edit the formula to match how you have it defined in FrontSpin. This too is defaulted to calls that are at least 2 minutes long.