High FEC/CRC Errors
- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page
- Plusnet Community
- :
- Forum
- :
- Help with my Plusnet services
- :
- Broadband
- :
- Re: High FEC/CRC Errors
High FEC/CRC Errors
07-03-2010 12:39 PM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
Out of curiosity would the high FEC/CRC errors make a huge difference on my broadband ?
How could I resolve these ?
I'm using a Thomson TG585 v7
Software Release: 7.4.4.7
Uptime: 0 days, 11:38:12 (I restarted the router almost 12 hours ago as I noticed I was on ADSL2 - G.992.3 only and not ADSL2+, a reboot put me back onto G.992.5)
DSL Type: G.992.5 annex A
Bandwidth (Up/Down) [kbps/kbps]: 444 / 5,335
Data Transferred (Sent/Received) [kB/kB]: 0.00 / 0.00
Output Power (Up/Down) [dBm]: 13.0 / 0.0
Line Attenuation (Up/Down) [dB]: 18.5 / 39.0
SN Margin (Up/Down) [dB]: 26.0 / 6.5
Vendor ID (Local/Remote): TMMB / 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): 0
Error Seconds (Local/Remote): 1 / 0
FEC Errors (Up/Down): 4,294,967,264 / 56,439
CRC Errors (Up/Down): 4,294,967,264 / 99
HEC Errors (Up/Down): 0 / 63
Thanks for any help.
Re: High FEC/CRC Errors
07-03-2010 1:38 PM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
ADSL2+ has different levels for interleaving ( INP 0, 1, 2, 4 and 8 ). This means that ADSL2+ Routers are depending heavily on their processors to detect and correct errors instead of retransmitting the data again. This doesn't usually affect your connection throughput but might cause a latency due to the calculations involved at both ends.
Re: High FEC/CRC Errors
07-03-2010 1:42 PM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
B.
Re: High FEC/CRC Errors
07-03-2010 1:47 PM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
Re: High FEC/CRC Errors
07-03-2010 1:50 PM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
Quote from: RamiDoodle This means that ADSL2+ Routers are depending heavily on their processors to detect and correct errors instead of retransmitting the data again. This doesn't usually affect your connection throughput but might cause a latency due to the calculations involved at both ends.
Thanks for the reply RamiDoodle, since the Thomson is depending heavily on the processor to detect and correct errors could this cause the Thomson to overheat and possibly cause the router to reboot on it's own ?
Re: High FEC/CRC Errors
07-03-2010 1:52 PM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
Quote from: Barry Also, those upstream readings are artificially high (a common problem with the TG585) - they're actually representing a negative number.
B.
Thanks for the reply Barry, I was just about to reply concerning the common problem with the TG585 but MrC replied and answered my next question.
Re: High FEC/CRC Errors
07-03-2010 1:57 PM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
Quote from: MrC Looks like a firmware bug as 2**32 = 4,294,967,296 = your figures + 32 . Basically the figures are bogus. If the router persistently reports this after reboots then another version of firmware might be the only cure.
Thanks for the reply also MrC, I did notice these errors were no where near as bad before but that's when I also noticed I was on G.992.3 instead of G.992.5 hence my reboot, so these errors only show up when connected to G.992.5 or was that just coincidence ?
Re: High FEC/CRC Errors
07-03-2010 2:31 PM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
It could be relevant as the firmware may take different code paths when handling and reporting ADSL2+ errors.
Quote from: Avalanche Thanks for the reply also MrC, I did notice these errors were no where near as bad before but that's when I also noticed I was on G.992.3 instead of G.992.5 hence my reboot, so these errors only show up when connected to G.992.5 or was that just coincidence ?
If you are feeling adventurous then there are quite a few later firmwares reported for this modem/router on http://download.modem-help.co.uk/mfcs-A/Alcatel/Modems/TG585/v7/Firmware/ and one of these may display more trustworthy error counts. However if your TG585v7 is currently working OK or you're not happy playing around with flashing and reconfiguring then it may be best to just leave it be or perhaps beg/borrow/steal a different make of modem/router
If you have an issue with connections persistently negotiating at ADSL2 then it might be worth (if you haven't already tried it) plugging your router directly into the test socket on your main BT socket to bypass your home wiring. If you then consistently get ADSL2+ negotiated you know your home wiring may need looking at. If you still get ADSL2 negotiated then it's down to the characteristics of your BT line and not so easy to improve (unless you've got audible noise on the line).
Re: High FEC/CRC Errors
07-03-2010 3:07 PM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
Cheers for the replies once again everyone.
Re: High FEC/CRC Errors
12-03-2010 6:23 PM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
50/50 or more like 20/80 ?
Re: High FEC/CRC Errors
12-03-2010 6:37 PM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
Try rebooting your router in the daytime - it might just get you into ADSL2+ territory.
Doesn't mean a significantly better speed though.
If you had a different router, you could probably force your noise margin (via software) down a bit to get a small improvement (500kbps).
Is your router plugged into the BT master socket?
"In The Beginning Was The Word, And The Word Was Aardvark."
Re: High FEC/CRC Errors
13-03-2010 6:58 PM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
Quote from: A Down CRC / HEC errors seem to be the most important - yours are OK.
Try rebooting your router in the daytime - it might just get you into ADSL2+ territory.
Doesn't mean a significantly better speed though.
I've done this a few times over a few days and although I get ADSL2+ at the time when I check later on in the evening it shows uptime to have disconnected and it's back to ADSL2.
Quote from: A
If you had a different router, you could probably force your noise margin (via software) down a bit to get a small improvement (500kbps).
Is your router plugged into the BT master socket?
I have 2 other spare routers, problem is they are what I upgraded from previously and therefore don't have ADSL2 also the property I live at now does not have a test socket available.
Re: High FEC/CRC Errors
13-03-2010 8:44 PM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
Quote from: Avalanche Seems my broadband keeps reverting back to ADSL2 rather than ADSL2+, looks like my line cannot handle the higher/different frequencies needed for ADSL2+, I'm unable to get hold of another router for testing purposes but what are the chances of this being a router issue rather than a line issue ?
50/50 or more like 20/80 ?
Hard to tell. Plugging your attenuation into http://www.kitz.co.uk/adsl/max_speed_calc.php gives potential sync rates quite a bit higher than what you are seeing, even for ADSL1. As the Thomsons are generally pretty good at negotiating decent sync rates I'd be tempted to point the finger at your wiring, either internal or external. Can you beg/borrow/steal another router to prove this?
What sync, SNR margin and error rates did you get on ADSL1?
Re: High FEC/CRC Errors
13-03-2010 9:15 PM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
Quote Line Attenuation (Up/Down) [dB]: 18.5 / 39.0
Have a look at https://portal.plus.net/support/broadband/speed_guide/broadband_terminology.shtml#dataRate
If you are not close to one of the "break points" - e.g.
Quote from 5120Kbps up to 4.5Mbps
from 5696Kbps up to 5Mbps
then you may get an increased sync rate - but no increase in actual speed!!!
"In The Beginning Was The Word, And The Word Was Aardvark."
Re: High FEC/CRC Errors
14-03-2010 1:58 PM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
Quote from: MrC Can you beg/borrow/steal another router to prove this?
What sync, SNR margin and error rates did you get on ADSL1?
I'll try and get hold of another router this week to see what difference it makes. It's hard to say what I got on ADSL1 as I moved premises and when broadband got activated at the new address I had then received my new Thomson router from PlusNet, I'll post back when I test with another router.
Thanks for the replies once again guys.
- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page