Why does restarting the modem fix latency?

In the last few days I've noticed poor internet performance. Today I ran a speed test and the results were abysmal... 10mb down and 0.18mb up (which really hurt, because I was trying to RDC from another location). I pay for 30mb down and 5mb up. Latency was at 128ms.

Before calling my ISP to give them a verbal lashing, I unplugged the modem and plugged it back in. I pretty much got top speed after doing that (with a latency of 7ms).

I'm the type of guy that likes to know what goes on under the hood. So what's the deal? What mysterious powers does restarting give to my modem?

Giovanni Galbo

Posted 2011-02-02T00:30:32.650

Reputation: 602

What type of modem? Cable or DSL? – None – 2011-02-02T01:01:48.980

It's a cable modem – Giovanni Galbo – 2011-02-02T01:13:24.673

Answers

Restarting can do wonders, a few things off the top of my head...

Reset NVRAM Clear any cached routes/dns info Cause it to resync with the local NID

ErnieTheGeek

Posted 2011-02-02T00:30:32.650

Reputation: 429

Modem firmwares run software - and software, being written by human beings, will have bugs and mistakes. You might check to see if your modem's firmware can be updated.

Incidentally, it could be unclean power or heat affecting your cable modem's performance. I've had mine connected to a UPS and I can't remember the last time I've had issues with it and needed to restart it.

LawrenceC

Posted 2011-02-02T00:30:32.650

Reputation: 63 487