CRC Errors

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kornflake

409 posts

Ultimate Geek

#113551 20-Jan-2013 12:03

Just wondering what a normal rate of CRC would be? over a 12 day peroid I have 121 errors down and 7 up. Should I be concerned?

raytaylor

4017 posts

Uber Geek

Trusted

#747771 20-Jan-2013 13:26

Personally i wouldnt be concerned unless it was impacting your internet connection.

When data is sent from the modem to the dslam (up) or from the dslam down to your modem (down), it is verified using a CRC check.

Eg. at one end, the content of the packet data is added up and a value is added onto the end.
At the other end, the packet is checked and the data should add up to the same value. If it doesnt, the Cyclic Redundancy Check fails and a retransmit request is sent.

Sent is: John jumped over the cat = 643
But arrives as John jumped on the cat = 634
we have an error
So the modem or dslam issues a resend request and if it arrives correctly, then it passes on to the next device in the line.

CRC failures can be caused by many things - usually interference. Interference can come from other broadband lines in the street. So this is why i say if its not causing you an issue, then dont worry about it.

Ray Taylor

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rugrat

3108 posts

Uber Geek

Lifetime subscriber

#747778 20-Jan-2013 13:46

That's only 10 a day. Sounds like a good connection.

When my internet was dropping out I was getting a few hundard crcs an hour.

If i'm on wifi and the microwave is turned on I see the crcs go up, so there's normal causes that can make them happen.

mercutio

1392 posts

Uber Geek

#749217 22-Jan-2013 23:33

If you get lots of CRC errors you can get corrupted downloads- you are fine though