Myself and other engineers deploying Unity Connection 7.0.X have experienced this issue with separate customers:
After installing the RTMT from the Unity Connection server plugin we Cannot see the Unity Connection tab on the left of the screen.
I opened a TAC case and got it working. The fix was as follows:
The C:\Documents and Settings\<username>\.jrtmt\Modules\plugins\Unity Plugin\126.96.36.199 folder was empty except for the file: dirlock.bin. This directory should have a number of files in it, all populated during the first login of RTMT. Once the folder had the correct files, the port monitor tab appeared and I could look at port monitor. Since this seems to be taking place with multiple customers, it is more than likely a Unity Connection/RTMT issue and not a firewall or something blocking these files from downloading. I tested installing on a server in the same subnet with the same results.
Is there a bug ID for this yet?