I would run a test before you assume it is the Linksys. Plug a computer directly into the T1 device, get it online. Let it run an hour or two, if you still lose connectivity, contact your ISP. If it goes away, contact Linksys for support.
1. It may simply need the latest firmware applied.
2. I have seen Linksys devices crashes from specifying a computer that is unavailable or having network issues on the log files page.
Matt J.