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Standard User MHC
(sensei) Tue 14-Oct-14 09:39:26
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Acceptable Error rates


[link to this post]
 
Currently monitoring a line with "issues". BT are involved and as yet have been unable to resolve the issues. It is believed to be a Modem/DSLAM issue rather than REIN or other external influences.

Every 30 minutes there is a massive spike in the latency - as shown in: Latency Spike

When this occurs there is an increase in the downstream errors: CRC increases by around 15-20, FEC by 1 or 2 and HEC by about 5. Occasionally the spike is a lot lower and just the upstream FEC increments by 2 or 3.

Reboots and resets do not change anything except the timing of the spikes - which are currently around 25 minutes apart, but could be up to 40 minutes and they seem to stay at the same spacing for quite a while and then suddenly change, so are "consistent". A reboot can alter them which points towards modem or DSLAM rather than an external influence.

So, ignoring the latency spikes themselves, is the general line performance acceptable with error rates of: CRCdn 30/hr, FECdn 2/hr, HECdn 10/hr and FECup 4/hr ?


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

M H C


taurus excreta cerebrum vincit
Standard User caffn8me
(knowledge is power) Tue 14-Oct-14 16:41:24
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Re: Acceptable Error rates


[re: MHC] [link to this post]
 
My home connection is very stable. It's been up for four days and four weeks.

I get;

CRCdn 32/hr
FECdn 0 (throughout entire period)
HECdn 5/hr
FECup 56/hr

Raw stats are;

Noise Margin:		  5.6 dB		 15.3 dB
Attainable Rate:	74608 kbits/s		 26766 kbits/s
Actual Power:		 13.7 dBm		  1.1 dBm
Per Band Status:       	D1 	D2 	D3 	U0 	U1 	U2 	U3
Line Attenuation(dB):   4.6	14.2	26.2	3.4	14.8	21.9	N/A	
Signal Attenuation(dB): 7.0	14.1	26.3	3.4	14.1	20.8	N/A	
Noise Margin(dB):       5.6	5.7	5.6	15.3	15.4	15.3	N/A	
Total FECC:		0			 43489
Total ES:		4972			 1766
Total SES:		32			 0
Total LOSS:		3			 0
Total UAS:		892			 892
Total LPRS:		0			 0
Total LOFS:		21			 0
Total LOLS:		0			 0


 		  DS Channel1	  DS Channel0	US Channel1	  US Channel0
Speed (kbps):	          0	       78968	         0	       19999
SRA Previous Speed:       0	       79987	         0	       19999
Previous Speed:	          0	       79987	         0	       19999
Reed-Solomon EC:          0	           0	         0	       10720
CRC Errors:	          0	       24342	         0	        2033
Header Errors:	          0	        4053	         0	           0
Interleave (ms):       0.00	        0.00	      0.00	        0.00
Actual INP:	       0.00	        0.00	      0.00	        0.00


I'd say your error rates look good. They're much better than most of the FTTC connections I manage,

Sarah

--
If I can't drink my bowl of coffee three times daily, then in my torment, I will shrivel up like a piece of roast goat

Spiders on coffee - Badass spiders on drugs
Standard User MHC
(sensei) Tue 14-Oct-14 17:15:26
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Re: Acceptable Error rates


[re: caffn8me] [link to this post]
 
Have just had a look at the speeds ...

Downstream attainable is around 74400 kbps
Sync 63550 kbps

Actual around 60000 kbps

74400 Attainable looks high for a line of around 450-500 metres! Unless the noise level is incredibly low!


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

M H C


taurus excreta cerebrum vincit


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Standard User caffn8me
(knowledge is power) Tue 14-Oct-14 17:59:32
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Re: Acceptable Error rates


[re: MHC] [link to this post]
 
I think attainable is a bit of a guesstimate. On my connection I sync and achieve download significantly above the calculated attainable.

Sarah

--
If I can't drink my bowl of coffee three times daily, then in my torment, I will shrivel up like a piece of roast goat

Spiders on coffee - Badass spiders on drugs
Standard User youngsyp
(member) Wed 15-Oct-14 13:56:44
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Re: Acceptable Error rates


[re: caffn8me] [link to this post]
 
Those are some nicely presented line stats. What device are the produced from?

Paul

ISP: Xilo
Service: Talk & Surf 100
Exchange: SMYG
Cabinet: 4
MSAN: Broadcom
Modem/ router: Billion BiPac 7800N
Attenuation:39.5dB
Target SNRM: 3.3dB or 52% of ISP
Current sync: 9755kbps
FTTC cab in place but not enabled..... yet!
Standard User caffn8me
(knowledge is power) Wed 15-Oct-14 16:57:01
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Re: Acceptable Error rates


[re: youngsyp] [link to this post]
 
In reply to a post by youngsyp:
Those are some nicely presented line stats. What device are the produced from?

Paul

That's a Cisco 887VA-M-K9

Sarah

--
If I can't drink my bowl of coffee three times daily, then in my torment, I will shrivel up like a piece of roast goat

Spiders on coffee - Badass spiders on drugs
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