piotrick
join:2003-01-27
Scarborough, ON
| CRC/HEC errors and packet loss?
Hi Everyone,
I just wanted to know if either CRC or HEC errors can cause packet loss on a DSL line.
I am receiving several CRC and HEC errors on my line (a couple hundred thousand after a 7 day period) and a couple thousand of "local errored seconds". These are only appearing on my downstream.
I'm on the 5mbit profile. My downtstream attenuation is 43, and my downstream noise margin fluctuates between 10.0 and 12.0 throughout the day.
My connection is very stable, however I get some packet loss when I play Counter-Strike 1.6 (yes, I know it's old lol) |
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TilhasBB
Formally Goden99
Premium
join:2000-08-05
canada | What modem are you using?
Can you try with no phones connected, modem in different locations or at demarc (where phone comes into bell) what are the stats there? |
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diskace
Ebox Senior
Premium,VIP
join:2002-02-21
1 edit | Yes, CRC errors mean the Cyclic redundancy check is not the same as sent by the remote host. Thus, the packets are corrupted or damaged and need to be re-received. This can lead to packet drop. It is normal to have a few CRC errors since communications is not 100% stable and lots of factors can affect transmission. Problems start when there is too much of them over a short period of time.
HEC errors are also important to watch. Header error checksum can also lead to packet drop.
You might want to test what TilhasBB suggested to see if it is improving.
--
Electronic Box Inc, Certified Geek.
First they ignore you, then they laugh at you, then they fight you, then you win - Gandhi |
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diskace
Ebox Senior
Premium,VIP
join:2002-02-21 | Just to complete, i think CRCs errors are more important to watch than HECs. CRCs use a more advanced method of checking for errors in data transmission. |
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piotrick
join:2003-01-27
Scarborough, ON
| Thanks for the info diskace!
TilhasBB, I'm using a SpeedTouch 780WL. Here are my line stats since rebooting the modem yesterday:
Link Information
Uptime: 1 day, 0:12:35
Modulation: G.992.1 annex A
Bandwidth (Up/Down) [kbps/kbps]: 800 / 5.056
Data Transferred (Sent/Received) [MB/MB]: 56,82 / 137,18
Output Power (Up/Down) [dBm]: 11,5 / 19,5
Line Attenuation (Up/Down) [dB]: 24,0 / 43,0
SN Margin (Up/Down) [dB]: 14,0 / 10,5
Vendor ID (Local/Remote): TMMB / ALCB
Loss of Framing (Local/Remote): 0 / 0
Loss of Signal (Local/Remote): 0 / 0
Loss of Power (Local/Remote): 0 / 0
Loss of Link (Remote): 0
Error Seconds (Local/Remote): 51 / 0
FEC Errors (Up/Down): 0 / 0
CRC Errors (Up/Down): 0 / 34.050
HEC Errors (Up/Down): 0 / 13.702
I think I might try disconnecting all the phones this weekend to see how it goes. Bell changed my exterior line over a year ago and put in a new demarc due to crackling on the line (and an eventual dead line as it actually broke). |
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