[Bellville North] WBLX DSLAM 5 IMAX congestion

Tinuva

Tinuva

The Magician
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2 weeks ago, I received a message from TelkomZA that bandwidth to this DSLAM was increased. I was super happy about that.
Time: 30-07-2013 10:53 AM
TelkomZA said:
Morning Tinuva

Bandwidth was increased, suspect round about the 25th.

Please let us know if you experience problems in the future.

Regards
Charl
Click to expand...



Today, 2013-08-16 14:00 it looks like the congestion is back :( Not as bad as back more than 2 weeks ago, but I guess all it took was a super cold weekend to keep everyone at home and push the limits again.

--Give a short explanation of the problem
Problem is congestion on the backhaul to the DSLAM I am connected to

--Give the first six digits of our phone number (like 011 425 xxxx)
021 910 xxxx
Although I know I am connected Bellville North WBLX DSLAM 5 IMAX

--ADSL line speed (like 1Mbps, 4Mbps etc)
10Mbps

--ISP name and account type (like MWEB uncapped)
Openweb Silver Red special 10Mbps uncapped
Used a telkom guest account to test latency to 1st hop.

--The time of day when you typically see these problems
Looking at my smokeping graphs over the Telkom Guest account, it was going on for a few days already at midnight, but today I see it on a saturday 2pm. Although I bet I will get to see it again anytime from 6pm in the evenings.

I monitor the latency here using smokeping: http://netmon.heaven.za.net/cgi-bin/smokeping.cgi?target=Telkom-DSL-Testing.Telkom-DSL-BRAS

wblx-dslam5-congestion-2013-08-17.PNG



Traceroute on my normal adsl account:
Code: 
C:\Users\Tinuva>tracert mail.google.com

Tracing route to googlemail.l.google.com [74.125.233.85]
over a maximum of 30 hops:

  1     6 ms    <1 ms    <1 ms  router.heaven.za.net [10.0.0.1]
  2   103 ms    96 ms    94 ms  196-210-201-1.dynamic.isadsl.co.za [196.210.201.1]
  3   124 ms   117 ms   125 ms  cdsl1-ctn-vl2173.ip.isnet.net [196.38.72.113]
  4   118 ms   124 ms   121 ms  196.35.115.128
  5   124 ms   110 ms   123 ms  168.209.6.12
  6   153 ms   150 ms   142 ms  168.209.100.13
  7   172 ms   176 ms   162 ms  196.26.0.130
  8   181 ms   179 ms   182 ms  74.125.49.66
  9   213 ms   197 ms   191 ms  64.233.174.57
 10   136 ms   144 ms   144 ms  jnb01s02-in-f21.1e100.net [74.125.233.85]

Trace complete.

Telkom guest account confirm 1st hop:
Code: 
[[email protected]] > /tool traceroute use-dns=yes interface=pppoe-telkomguest www.telkomsa.net
 # ADDRESS                                 RT1   RT2   RT3   STATUS
 1 dsl-165-145-74-01.telkomadsl.co.za      162ms 154ms 155ms
 2 0.0.0.0                                 0ms   0ms   0ms
 3 0.0.0.0                                 0ms   0ms   0ms

Line stats are fine, so it is not the line:
Code: 
DSP Firmware Version	DMT FwVer: 3.10.17.0_A_TC, HwVer:T14F7_5.0
DMT Status	Up
Operational Mode 	ADSL2+
Upstream	987 kbps
Downstream	10015 kbps
SNR Margin (Upstream)	7.1 db
SNR Margin (Downstream)	10.3 db
Line Attenuation (Upstream)	14.4 db
Line Attenuation (Downstream)	27.0 db
 
Received a PM form TelkomZA @ 19-08-2013 08:30 AM

Good Day

I have forwarded your information to the relevant parties to investigate further and to find a suitable solution
Have a wonderful day

reagrds
^GH
Click to expand...

The latency/congestion this weekend wasn't as bad as I thought it would be, but it usually starts like it did, this weekend and only gets worse. Hope we can have it sorted soon.
 
Got a call from Jerome today re my escalation.

Sounds like it was escalated again to the corresponding department. He could see it was previously upgraded from 110Mbit to 140Mbit.

So will see what happens, even Jerome didn't sound too optimistic this time :(
 
Tinuva said:
Got a call from Jerome today re my escalation.

Sounds like it was escalated again to the corresponding department. He could see it was previously upgraded from 110Mbit to 140Mbit.

So will see what happens, even Jerome didn't sound too optimistic this time :(
Click to expand...

does imax not run around 600Mbit backbone? or i am being stupid :p

i am sure someone said something like that last time.
 
hereticangel said:
does imax not run around 600Mbit backbone? or i am being stupid :p

i am sure someone said something like that last time.
Click to expand...
You are not entirely incorrect, but on the right path :)

1. Telkom run their Metro Ethernet links maximum up to 600Mbps.
2. IMAX DSLAM means that Metro Ethernet backhaul is in use.
3. Multiple DSLAMs in an area share the same backhaul link!

Also, Telkom limits the bandwidth to each DSLAM on this shared link, with a policy rate limit in the router(BRAS) config (software config). So even though the link/backhaul can do more traffic than this policy rate limit, this is currently where the limit is for this DSLAM.
 
I am also connected to the same exchange. I have an Openweb Uncapped Gold account and it has been running smoothly. I felt some hiccups on Sunday, but that is about it :).

I have a 10Mbps line. My router is only syncing at around 6.5Mbps though. According to Telkom it's because of the distance between the exchange and my house.

What speeds are you syncing at and how far are you from the exchange?
 
My sync speed is in the 1st post, here it is again:

DMT Status Up
Operational Mode ADSL2+
Upstream 984 kbps
Downstream 10015 kbps
SNR Margin (Upstream) 6.2 db
SNR Margin (Downstream) 9.4 db
Line Attenuation (Upstream) 14.1 db
Line Attenuation (Downstream) 26.0 db

Telkom actually said I would be having problems since I am 2.4km from the exchange, yet the line is solid stable. Must admit, lately the latency haven't been much of a problem, but then again the GF also kept my busy so haven't been playing much games.

According to smokeping though, we still get high latencies at midnight in the evenings, so technically we not too bad off, unless you want to game at midnight.
 
This is what I get: (I think I am a little bit further from the exchange than you are)

Downstream 6423 kbps
Upstream 1019 kbps
Line Attenuation Downstream 48.5 db
Line Attenuation Upstream 25.5 db
Noise Margin Downstream 5.2 db
Noise Margin Upstream 3.8 db

This is on a 10Mb line.
 
Last edited:
r00ster said:
This is what I get: (I think I am a little bit further from the exchange than you are)

Downstream 6423 kbps
Upstream 1019 kbps
Line Attenuation Downstream 48.5 db
Line Attenuation Upstream 25.5 db
Noise Margin Downstream 5.2 db
Noise Margin Upstream 3.8 db

This is on a 10Mb line.
Click to expand...
Woah hectic, I am surprised your line doesnt drop the whole time. Both your readings are below 6 db for SNR, which is the minimum required, not to mention for stable you want to be at 8db+.

You need to figure out why your attenuation is so high, it may be more than just the distance. Your line can rather be classified as a 6mbit line rather than a 10mbit line.
 
Okay cool. I think I need to contact Telkom asap.

In your opinion, what would be the fastest way to get them to react and actually solve the issue?
 
Okay so I did a little bit of research. I am about 3-4 km from the exchange. Thus my line att. is normal.

That SNR value bugs me though.
 
Well if you really are 3-4 KM away, there aint much you or Telkom can do. If your line is not stable, you should drop the speed, but if its stable enough for you, you can leave it there.
 
Eish. Not again. My internet has also been horrid for the whole of today.

Something is up with this exchange.
 
So the GF left early tonight, though YES I can play games!!!

NOT!!!

DSLAM is Congested tonight like used toilet paper:(

wblx-dslam5imax-2013-10-17.PNG
 
It is about time I update this page again.

Most evenings it is not possible to play games, sadly as this exchange is congested, and I doubt the current speed upgrades are going to help much.

2013-11-14
smokeping-wblvx-dslam5-1.png

smokeping-wblvx-dslam5-2.png
 
Not sure when this happened, but I think in the past 4 days (specifically think it happened Tuesday morning 3 Dec 2013) or so Telkom must have upgraded the backhaul (rate limit setting) for this DSLAM, because it changed from 140Mbit/sec to 170Mbit/sec and I can tell, all latency problems have gone away.

It is really amazing, to be able to play games again at night!
 
Who is providing you with information regarding the DSLAM backhaul speed?

I remember going through this exact process with Telkom a few months ago, DSLAM was limited to 100Mbps, they increased limits to 150Mbps and traffic shot up to 145Mbps, apparently. Pro-active monitoring much?

I'm glad your issue is sorted.
 
DeatheCore said:
Who is providing you with information regarding the DSLAM backhaul speed?

I remember going through this exact process with Telkom a few months ago, DSLAM was limited to 100Mbps, they increased limits to 150Mbps and traffic shot up to 145Mbps, apparently. Pro-active monitoring much?

I'm glad your issue is sorted.
Click to expand...
I get some of the information myself, I can't tell you how otherwise people could get into trouble.

What I do know is, while Telkom have pro-active config updates for rate limits on their main backbone, they don't have it for DSLAMs for some strange odd reason I can't remember.
 
To bring back this topic, this is what I have currently for this DSLAM.
Great healthy ping 5-10ms in the day on 1st hop after router, then from 5-6pm through to 12 midnight, climb to 400+
See graph for the "congestion cycle"

1.jpg

Tried different account, also TelkomGuest, same outcome. Ticket open with Telkom.....

Any-one else having this currently?
 
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