CRCs spike on incoming call
Hi there
Sorry for the somewhat lengthy explanation below… There are a couple of questions at the end if you can manage to get that far – and I’d be really grateful for any advice!
Until a few days ago I had a very stable connection which had been up for 49 days with bandwith 888/6561 and total CRC errors over the 7 weeks of 498 up / 12666 down. Then the connection went down (several times in short succession), and reconnected at 312/6262 (a very much lower upstream sync), and SN margin 14.5/6.5.
I had a further drop yesterday afternoon, and when the router reconnected it was at an all-time low of 32/4803 with SN margin of 29.2/12.9. I had routerstats running at the time and noticed there had been a spike in upstream CRC errors (from 50ish to 228) just before the connection dropped, possibly related to an incoming call. I restarted the router and managed to get back to pretty well normal speeds for my line: 888/6346.
I then tried ringing my landline and noticed that an incoming call results is a sudden increase in upstream CRC errors – anything between 10-20 and 80-100+, and twice calling my line caused the connection to drop. I rang technical support, explained everything but didn’t manage to make any progress – he just told me my line stats were currently fine and to try a different filter (I already had, and was plugged into the test socket) and to try moving the router to a different socket in case it was a power surge (I’m not sure how many sockets he thinks I have within a meter of my phone socket… And do you really get power surges on one socket but not others on the same ring main????)
Anyway… Having looked in this and a few other forums I am now confused as to whether this spike in CRC errors on receiving a call is (a) perfectly normal, or (b) an indication of a possible fault on the line. Does anyone have an opinion on this? I should add that when my connection does drop, it very often does come back up with a much reduced upstream sync – often in the 200s.
If this is indicative of a possible problem – how on earth do I persuade the technical support team to do something more than looking at my current line stats and declaring everything is fine?
I have restarted my router today and everything looks good again at the moment – router stats are:
Uptime: 0 days, 2:47:22
DSL Type: ITU-T G.992.3
Bandwidth (Up/Down) [kbps/kbps]: 888 / 6,587
Data Transferred (Sent/Received) [MB/MB]: 22.74 / 170.54
Output Power (Up/Down) [dBm]: 12.8 / 0.0
Line Attenuation (Up/Down) [dB]: 25.3 / 41.5
SN Margin (Up/Down) [dB]: 9.3 / 6.1
System Vendor ID (Local/Remote): TMMB / ----
Chipset Vendor ID (Local/Remote): BDCM / IFTN
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): -
Error Seconds (Local/Remote): 5 / 0
FEC Errors (Up/Down): 389 / 1,218
CRC Errors (Up/Down): 0 / 8
HEC Errors (Up/Down): 0 / 56
Thanks in advance!
Alan
Sorry for the somewhat lengthy explanation below… There are a couple of questions at the end if you can manage to get that far – and I’d be really grateful for any advice!
Until a few days ago I had a very stable connection which had been up for 49 days with bandwith 888/6561 and total CRC errors over the 7 weeks of 498 up / 12666 down. Then the connection went down (several times in short succession), and reconnected at 312/6262 (a very much lower upstream sync), and SN margin 14.5/6.5.
I had a further drop yesterday afternoon, and when the router reconnected it was at an all-time low of 32/4803 with SN margin of 29.2/12.9. I had routerstats running at the time and noticed there had been a spike in upstream CRC errors (from 50ish to 228) just before the connection dropped, possibly related to an incoming call. I restarted the router and managed to get back to pretty well normal speeds for my line: 888/6346.
I then tried ringing my landline and noticed that an incoming call results is a sudden increase in upstream CRC errors – anything between 10-20 and 80-100+, and twice calling my line caused the connection to drop. I rang technical support, explained everything but didn’t manage to make any progress – he just told me my line stats were currently fine and to try a different filter (I already had, and was plugged into the test socket) and to try moving the router to a different socket in case it was a power surge (I’m not sure how many sockets he thinks I have within a meter of my phone socket… And do you really get power surges on one socket but not others on the same ring main????)
Anyway… Having looked in this and a few other forums I am now confused as to whether this spike in CRC errors on receiving a call is (a) perfectly normal, or (b) an indication of a possible fault on the line. Does anyone have an opinion on this? I should add that when my connection does drop, it very often does come back up with a much reduced upstream sync – often in the 200s.
If this is indicative of a possible problem – how on earth do I persuade the technical support team to do something more than looking at my current line stats and declaring everything is fine?
I have restarted my router today and everything looks good again at the moment – router stats are:
Uptime: 0 days, 2:47:22
DSL Type: ITU-T G.992.3
Bandwidth (Up/Down) [kbps/kbps]: 888 / 6,587
Data Transferred (Sent/Received) [MB/MB]: 22.74 / 170.54
Output Power (Up/Down) [dBm]: 12.8 / 0.0
Line Attenuation (Up/Down) [dB]: 25.3 / 41.5
SN Margin (Up/Down) [dB]: 9.3 / 6.1
System Vendor ID (Local/Remote): TMMB / ----
Chipset Vendor ID (Local/Remote): BDCM / IFTN
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): -
Error Seconds (Local/Remote): 5 / 0
FEC Errors (Up/Down): 389 / 1,218
CRC Errors (Up/Down): 0 / 8
HEC Errors (Up/Down): 0 / 56
Thanks in advance!
Alan
Hi there.
I'd recommend keeping a eye on your connection as it could be a intermittent issue.
If it occurs again the best course of action would be to raise a fault online. I've included the link below for you.
http://faults.plus.net
If you have any further issues please let us know.
I'd recommend keeping a eye on your connection as it could be a intermittent issue.
If it occurs again the best course of action would be to raise a fault online. I've included the link below for you.
http://faults.plus.net
If you have any further issues please let us know.
Thanks, both. Always good to have such quick support from this forum 
@ Oldjim
Thanks for the suggestion. I tried ringing from a mobile with new filter and no phones plugged in as suggested - still had a burst of CRC errors, though not a vast number. Quiet line test seems not to have any obvious noise. Will let the connection run without any further messing around for a day or so, then try again and raise a fault if still having issues
Cheers
Alan
@ Oldjim
Thanks for the suggestion. I tried ringing from a mobile with new filter and no phones plugged in as suggested - still had a burst of CRC errors, though not a vast number. Quiet line test seems not to have any obvious noise. Will let the connection run without any further messing around for a day or so, then try again and raise a fault if still having issues
Cheers
Alan