AT&T Microcell and Routers

Our area has never gotten good cell phone coverage.  Doesn’t really mater what carrier we used … AT&T or Verizon.

When AT&T announced that it was going to be making “MicroCells” available, I decided to get one … as it would help our cell phone coverage.

The MicroCell has been working fine for more than a year … but, all of a sudden (or so it seemed), it stopped working correctly.

I contacted AT&T and they tried a few things and asked me to try cycling power (unplugging it and plugging it back in).  Nothing worked.  I asked them to check to see if it was still under warranty … it wasn’t.

After I determined that AT&T wasn’t going to be able to help … I started thinking a bit more … and I remembered one of my favorite catch phrases: “If nothing’s changed, and something doesn’t work the same, then something’s changed”.

This got me to thinking … what did I change on the network recently that might have caused a problem?

Only one thing came to mind … I upgraded the firmware on my Netgear WNDR3700 router.

That reminded me of a setting I had to change on the router in order to get the MicroCell to work in the first place … I had to change the MTU value to a specific value … 1492.  The details on the change, and how do to it on various routers, can be found on this AT&T knowledge base article.

I hadn’t thought about the MTU setting because, when I upgraded the firmware on the router, all the other settings had been preserved.  This one, however, had been set back to it’s default (1500 I think).

After I changed the MTU value, and rebooted the router, the MicroCell worked fine.

1 thought on “AT&T Microcell and Routers

  1. Brian Dolinar

    I’ve seen MTU settings causing problems more and more lately, on both hardware and software. Good reminder to check that early in troubleshooting.


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