If you are thinking of calling Airvana Tech support (1-866-556-7310), you need to INSIST on speaking with a guy by the name of Rene. He was AWESOME with the setup of my Airvana!! He knew that with my other network devices (Scientific Atlanta Modem [COMCAST Internet], Linksys E2000 router, Vonage Device, and AIRVANA of course), there was no question in his mind that you can connect the E2000 directly to the Modem. Then connect the Airvana into port 1 and my Vonage device into port 2 of the E2000. Once all 4 devices were rebooted, the Broadband, GPS, and Mobile LED's were all solid Green. I don't have VoIP Phone svc thru Sprint, so that LED is not on at all.
One other note I want to share is the fact that the external GPS antenna that comes with the AIRVANA doesn't NEED to be plugged in unless you can't place the AIRVANA near a window with a clear view of the sky. Hopefully this post helps out a few folks with a similar situation as I do.