Broadband Related > ADSL Issues
ADSL Line Outages - Equipment or Line
aesmith:
We've been getting some strange outages. What seems to happen is the line suddenly goes down in terms of function, the ISP sees it as Down and no data is transferred. PPP polling from the ISP is down. Meanwhile both BT and my router see the DSL still in sync with SNR varying minute by minute as normal (ie not frozen at last remembered values). In some episodes the router SNR has dropped down to near zero or even sub zero, this drop happening instantaneously but followed by small variations around that value for the remainder of the outage.
On all occasions the line has immediately resumed normal service the moment a DSL retrain is triggered either by router command or by disconnecting cable (or power cycle).
Any ideas? I was thinking equipment rather than line, because of the fact that it can always be cleared by a retrain, whereas if it was interference or other line issue then I wouldn't expect it to clear until the condition improved.
Same symptoms with my original Billion 7800DXL and with the new Zyxel 8924.
Thanks in advance, Tony S
burakkucat:
That is rather perplexing. I would agree with your suspicion; it does seem to be a CPE problem rather than a circuit (line) problem.
One other thought. Could there be a problem with the ISP/CP's equipment? Power-cycling or software forcing a re-train with the equipment at your end of the circuit also forces the ISP/CP's equipment to re-train the (line-card) port assigned to your circuit.
aesmith:
I grabbed a couple of screenshots from an episode last night. The line came back up immediately the router was reset. Noise margin was bumping around as normal, no CRCs being detected, then with no prior indication noise margin dropped to near zero with errors off the scale. During this time BT status test showed line in sync, noise margin normal. A&A saw it has hard down.
Yesterday 22:33:30 Yesterday 22:33:46 BT Test xDSL Status Check:Pass Standalone sub test passed successfully.Pass OK. Circuit In Sync BRAS=2676kb/s FTR=3200kb/s MSR=4000kb/s ServOpt=1 I/L=I A SERVICE OPTION CHANGE ORDER IS IN PROGRESS ON THIS LINE Up Sync=804kb/s LoopLoss=32.4dB SNR=6.1dB ErrSec=0 HECErr=0 Cells=3144 Down Sync=3044kb/s FTB LoopLoss=53dB SNR=5.9dB ErrSec=0 HECErr=N/A Cells=3532 auto-DOWN@a
Sync speed is low as well now, at all times. Down from normal which should be around 4.2meg to now struggling to hit 3.7.
Edit - didn't realise the CRC graph hadn't attached
burakkucat:
I am struggling to understand what could be the cause of your problem. :-\
aesmith:
Might be time to swap back to the Billion router, so I get a true before/after comparison. It may be that the Zyxel is simply slower since I've never tried one when the line was good.
Navigation
[0] Message Index
[#] Next page
Go to full version