Kitz Forum
Broadband Related => FTTC and FTTP Issues => Topic started by: art37 on April 10, 2017, 02:47:35 PM
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Following a period of line instability due to a PCP change, my connection was all over the place with over 44 dis/re-connections in a week. My ISP really didn't want to know so I ruled out issues on my side of the connection as best I could, and I sent AVM a diagnostics test from my Fritz!Box. The Fritz!Box is fine but they have commented on 84 PPPoE errors in a week and the CRC error rate. To put the former into context, I always get one or two PPPoE errors when there is a re-connection and then the line tends to run without too many issues. It is currently holding 74411/20000 on a SNR of 6. the line has been stable at these speeds for just over 4 days. The CRC rates are 0.09/per min (F!B) and 0.01/per min (central exchange). I have a wifi repeater connected to a wired switch in my set up. AVM has asked 'what does your ISP say': I hesitate to ask. Any thoughts/comment?
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The CRC numbers are very dependant on if the line is fastpath, interleaved or with G.INP active. It also matters which ISP you use, as different ISP's allow different amounts of errors.
0.09/per min is just under 6 per hour and around 130 per 24 hours. That's perfectly acceptable and absolutely of no concern. We don't watch the CRC figure so much but rather the ES (Error Seconds). An Errored Second is a second containing one or more CRC errors (or various other errors). 130 CRC's could mean 130 ES, but it could also mean 1 ES (If all 130 CRC's happened in the same second).
Your ISP's ES threshold is likely to be either 1440 or 2880 per day. You likely have under 100 ES per 24 hour going by your 0.09 CRC's per min figure. I have no idea why AVM have raised issue with those CRC rates as they look low to me. I would guess from those numbers your line is fastpath, though that's just a guess. If it is then those numbers are not just fine but excellent.
I'm unable to help with the PPPoE errors as this is an area I'm less familiar with. You would need to expand on what you mean by error though. Is the Fritz!box simply dropping the PPP session?
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Thanks - I am on fast path using Zen's GEA backhaul. These are my current stats after 3 1/2 days:
Receive Direction Send Direction
Max. DSLAM throughput kbit/s 80000 20000
Min. DSLAM throughput kbit/s 128 128
Attainable throughput kbit/s 74411 25782
Current throughput kbit/s 74411 20000
Seamless rate adaptation off off
Latency fast fast
Impulse Noise Protection (INP) 0 0
G.INP off off
Signal-to-noise ratio dB 6 9
Bitswap on on
Line attenuation dB 13 12
Profile 17a
G.Vector off off
Carrier record A43 A43
Error Counter
Seconds With Not Remediable Errors (CRC)
Errors (ES) Many
Errors (SES) per
Minute Last
15 Minutes
FRITZ!Box 312 0 0.07 0
Central exchange 48 9 0.01 0
My router log on re-connection is typically like this:
13.30.39 DSL synchronisation (training)
13.31.11 DSL is available. DSL synchronisation exists with 74411/20000 kbits/s
13.31.18 PPPoE error: Timeout
13.31.28 Internet connection established successfully. IP address.........
PPPoE errors preventing me getting an internet connection were an issue when I installed my 7490 over 3 years ago. BTOR came out and did a Lift and Switch and re-built the connection with BTW.
Although, I have lost over 10Mbps max attainable speed since a recent PCP change, I am pretty happy with my line's stability. The downstream speed has hunted around to find stability - with the downstream SNR falling as low as 4 - but it now seems to have settled on a SNR of 6 after about 4 re-connects since a GEA migration on the 15th March. I am on an ECI cabinet so no G.INP.
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My router log on re-connection is typically like this:
13.30.39 DSL synchronisation (training)
13.31.11 DSL is available. DSL synchronisation exists with 74411/20000 kbits/s
13.31.18 PPPoE error: Timeout
13.31.28 Internet connection established successfully. IP address.........
I don't think there's anything wrong with that timeout being just 7 seconds after connect.
OR block PPP for a bit after a resync so that the correct line rates get sent to the ISP.