The Border campaign does warn you in DCS that you should read the documentation for the HIP regarding radio communications as the knowledge needed to know how to work the different radios will be extremely important in completing each mission. You need to be able to use the radios to talk with Airfields, FARPs, Escort pilots, Ground Crew, Special Forces crews. You will also want to know how to work the ADF as well as the ARC-UD navigation systems.
In the briefing, you will also want to use the arrow button to click through the different screen shots detailing your routes as the debriefing is rather vague. The debriefing might state objective as taking off at point A and landing at point B but doesn't mention you need to land at 1 or 2 other places along the way so pay more attention to the screen shots. Your kneeboard will also outline your flight plan and include waypoints as well.
The most important thing is proper tuning of the radios which included the R-863 and R-828 radios. The majority of the comms are easily done through the radio located by the co-pilots left butt cheek on the center pedestal.
I started the border campaign yesterday and so far completed the first 3 missions without any problems. As long as you can finish with a result of 100, you have completed the mission. I hope this helps.