I had a major issue with poor and/or intermittent system performance with the Extender which I THOUGHT was resolved, but today, once again, the network red light's flashing and I have no service at home. this happens constantly with Verizon and apparently it's nationwide. I cannot understand how a major corporation can sell a product this poor and hold their heads up. At $250.00 it should work flawlessly, but if I get 50% performance I'm lucky. If I got 50% performance from my aircraft, I'd be in the trees.
The flashing WAN light indicates traffic to/from the NE. If you're on a phone call, it would be flashing as it transmits your voice and receives the other party's voice traffic.
As noted by others, Verizon's service for the NE's has not been completely reliable. But that usually manifests itself with a red light on your NE unit.
You may be having a bandwidth conflict problem on your local area network (LAN). If others on the same LAN are using Bit Torrent or similar Peer-to-Peer services, it may affect performance of the NE, and could make your calls un-intelligible. Most routers or switches for home use don't support the notion of prioritizing traffic for certain devices, except for certain Online Gaming ports. Verizon will tell you to run a test, especially when you're experiencing problems, to see if there's a conflict or bottleneck in your LAN setup. Visit the site below and run a free test using the LAN port you use for your NE device.
Many home DSL connections support only 256k upload speeds. If you have three calls going on the NE, you're using about half (at 40k each, x 3 = 120k) of your available upload bandwidth. If your router can't prioritize the Voice traffic over other traffic, your voice transmissions will suffer (break up). Even with more bandwidth, heavy traffic could cause problems with clean voice connections unless your router supports prioritization.