Can ping be low with exchange congestion?

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21stcn

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Hi,

My 4Mbps connection has the symptoms of exchange congestion in that, while it is testing at around 3.6 Mbps during the day on week days, every evening from about 8pm, and usually the whole weekend, the speed is between 0.7 and 1 Mbps. The things is, the ping never is more than about 60ms. Right now my speed is 0.8 Mbps but the ping is only 25ms. This for months now. When I test on http://www.bandwidthplace.com/ (international servers), 0.35 Mbps.


I have ruled out the isp and shaping (tried multiple capped/uncapped accounts) over many weeks. I have also had telkom come check the line and it is apparently fine. I am a few hundred metres from the exchange and my SNR and attenuation are really good. The connection is always syncing at 4Mbps and not losing connection, and I have tried another router.

It is only evenings and weekends, but it seems international connections are a problem. In ping plotter there is a lot of jitter at these times (above 50ms). Is this exchange congestion or any other suggestions?

Muizenberg 021 788 (no reports of it on mybb)

Below is a tracert to bbc.co.uk:

Tracing route to bbc.co.za [216.8.179.23]
over a maximum of 30 hops:

1 <1 ms <1 ms 1 ms 10.0.0.2
2 10 ms 10 ms 11 ms 105-xx-x-xx-esr-lo.mtnbusiness.co.za [105.xx.x.xx]
3 13 ms 13 ms 13 ms 41.181.221.254
4 35 ms 34 ms 35 ms tb-dca-2.za--qux-a.za.mtnbusiness.net [41.181.184.28]
5 35 ms 35 ms 34 ms unc-cpt-1.mtnns.net [196.44.18.8]
6 17 ms 26 ms 17 ms 196.44.31.106
7 156 ms 157 ms 157 ms am-cr-1.am--lt-cr-1.uk-a.mtnns.net [196.44.31.221]
8 159 ms 158 ms 159 ms ls-pr-1.uk--ls-cr-1.uk-a.mtn.net [209.212.111.83
]
9 157 ms 157 ms 161 ms 40gigabitethernet1-1.core1.lon1.he.net [195.66.224.21]
10 227 ms 226 ms * 10gigabitethernet10-4.core1.nyc4.he.net [72.52.92.241]
11 245 ms 237 ms 237 ms 10gigabitethernet1-2.core1.tor1.he.net [184.105.222.18]
12 243 ms 244 ms 244 ms managed-network-systems-inc.10gigabitethernet3-1
.core1.tor1.he.net [209.51.163.38]
13 243 ms 242 ms 243 ms ndcolo-gw.wndson17.mnsi.net [216.8.136.66]
14 243 ms 244 ms 243 ms ptr-216-8-179-23.ptr.nextdimensioninc.com [216.8.179.23]


Thanks
 
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If it's exchange congestion then the ping of the 2nd hop would be through the roof.
 
vicv said:
If it's exchange congestion then the ping of the 2nd hop would be through the roof.
Click to expand...

That's what I thought. Any idea why it might become unusable only during peak times if it isn't congestion exchange?
 
Afrihost 4Mbps uncapped business. I tried webafrica (IS) 2GB capped last night and same problem.
 
It looks like Afrihost. If it is, contact Afriman via PM and they will look at it for you.

*edit* only saw your post now. Contact Afriman in any way.
 
vicv said:
If it's exchange congestion then the ping of the 2nd hop would be through the roof.
Click to expand...
99% of the time this is true.

BUT

If you are on a congested exchange where Telkom uses an ASR instead of an ESR, the DSLAM can inform the ASR when the backhaul is congested, and then the ASR starts to rate limit all pppoe sessions going to that DSLAM, to keep latency low.

This is a new thing, and these are not commonly in use on the Telkom network yet. So what the OP describes, sounds like congestion to me.
 
Tinuva said:
99% of the time this is true.

BUT

If you are on a congested exchange where Telkom uses an ASR instead of an ESR, the DSLAM can inform the ASR when the backhaul is congested, and then the ASR starts to rate limit all pppoe sessions going to that DSLAM, to keep latency low.

This is a new thing, and these are not commonly in use on the Telkom network yet. So what the OP describes, sounds like congestion to me.
Click to expand...

Anything's possible
 
Thanks for that info @ Tinuva!

I'm currently having that issue where my ping is very low, but I cannot get more than 1Mbps on my 4Mbps ADSL connection between 07:00 - 00:00.
I can experience a difference between when my ISP is throttling me and when Telkom's infrastructure is. Like when my ISP is throttling me, I can still browse, but it is just slow. When Telkom is throttling me, I have heavy packet loss and websites won't even load slowly.

The stupid Telkom techie told me its my alarm/telephone or modem that is at fault. Yes, when I disconnect the alarm/telephone my downstream SNR improves from 10dB to 14dB, but my speed is just as terrible.

What I find bad about the Telkom fault reporting is that you cannot give a description or pick that congestion is an issue, and then the Telkom techies keep on rocking up wanting to do an ADSL line test.

I reckon that if Telkom doesn't resolve my congestion issue within the next week that I'm going to tweet/ask TelkomZA to have a look at it, because they always resolve the issue in a short time!
 
Tinuva said:
If you are on a congested exchange where Telkom uses an ASR instead of an ESR, the DSLAM can inform the ASR when the backhaul is congested, and then the ASR starts to rate limit all pppoe sessions going to that DSLAM, to keep latency low.
Click to expand...

Thanks Tinuva. This is new information to me. I'll just phone telkom and find out ... (chance of success: ~0.01%).

Seriously though is there an easy way to discover if this is the case without spending weeks seducing a telkom techie?

I think I'll just move my line to AH and then at least I can *** on someone.
 
Pada said:
Thanks for that info @ Tinuva!

I'm currently having that issue where my ping is very low, but I cannot get more than 1Mbps on my 4Mbps ADSL connection between 07:00 - 00:00.
I can experience a difference between when my ISP is throttling me and when Telkom's infrastructure is. Like when my ISP is throttling me, I can still browse, but it is just slow. When Telkom is throttling me, I have heavy packet loss and websites won't even load slowly.

The stupid Telkom techie told me its my alarm/telephone or modem that is at fault. Yes, when I disconnect the alarm/telephone my downstream SNR improves from 10dB to 14dB, but my speed is just as terrible.

What I find bad about the Telkom fault reporting is that you cannot give a description or pick that congestion is an issue, and then the Telkom techies keep on rocking up wanting to do an ADSL line test.

I reckon that if Telkom doesn't resolve my congestion issue within the next week that I'm going to tweet/ask TelkomZA to have a look at it, because they always resolve the issue in a short time!
Click to expand...

Sounds like a similar thing Pada. You should buy a few capped gigs to rule out all shaping.

Please keep the thread updated with your findings. I'll do the same. Hopefully we can figure this out.

Telkom has just added a very useful section to their online troubleshooter for congestion! It goes like this:

Problem: Is your problem caused by a congested exchange?
Solution: Telkom does not guarantee thoroughput

It is ****ing stupid that your only options are to report a line fault or reset your modem. Almost as stupid as having to pay for a phone line you never intended on using. But if you let telkom get to you it's a slippery slope down to madness. My poor keybpard knows.
 
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@21stcn:
I can say with absolute certainty that it is congestion on the Telkom infrastructure and not shaping/throttling done by the ISP, because I've tested with (capped) Afrihost (MTN), (capped) WebAfrica (IS) and (gold uncapped) OpenWeb (IS) accounts.
 
Pada said:
@21stcn:
I can say with absolute certainty that it is congestion on the Telkom infrastructure and not shaping/throttling done by the ISP, because I've tested with (capped) Afrihost (MTN), (capped) WebAfrica (IS) and (gold uncapped) OpenWeb (IS) accounts.
Click to expand...

Ok good to hear.

This ASR / ESR thing sounds plausible.
 
I can't remember if it was a friend at Telkom or another contact who told me that, but it is possible it was a Telkom tech on the phone after I asked about the different options Telkom have when I first reported my exchange's congestion to TelkomZA. Either way, this ASR congestion with rate limiting is new, and I believe is going to be the most annoying of them all to pin-point as congestion and getting it resolved. At least with high latency its easy, but when the ASR rate limits and you don't see high latency...its 10 times more difficult to diagnose, not to mention annoying.
 
I had the exact same symptoms. I booked faults daily as they kept clearing them without repairing. My ISP is Telkom. Both TelkomZA and Ranger tried to assist but eventually said it was congestion, even though my pings didn't show it. The said I have to wait for the exchange to be upgraded.
Suddenly about 2 months later it sorted itself out. I now get full speed at any time. My exchange has not been upgraded yet.
 
Awesum said:
I had the exact same symptoms. I booked faults daily as they kept clearing them without repairing. My ISP is Telkom. Both TelkomZA and Ranger tried to assist but eventually said it was congestion, even though my pings didn't show it. The said I have to wait for the exchange to be upgraded.
Suddenly about 2 months later it sorted itself out. I now get full speed at any time. My exchange has not been upgraded yet.
Click to expand...

Man, that was like an ADSL ghost story, the night before Halloween.

Thanks for sharing your experience. It's sounding more and more like some sort of external interference that is occurring at these times, I just don't know what.

I spent months last year (before TelkomZA appeared) when I was at a different flat phoning Telkom daily about congestion and logging faults, even though they checked the line and threatened me with call out fees and all that ****, but that WAS obvious congestion, and dozens of people on mybb confirmed it and nagged telkom, and they eventually upgraded it.

With this problem there is no one complaining in the area and the ping on the second hop is too low (to be honest I don't have the energy to put in that sort of effort again). I just don't know what to do because at those times, I want to use the internet and need full bandwidth which I am ****ing paying a fortune for.

In some sort of capitalist democracy this would be an obligation of telkom to fix (providing the infrastructure and charging for it), but despite telkom signing up to twitter and facebook (even after my father) we all know they're still a bunch of ridiculous bloody jokers. They're just like, 'Sorry we only do lines and port resetting, maybe try another dsl provider? Haha. Sorry, I meant **** you.'

I guess the question is: does any one have any suggestions as to what might be a potential cause for congestion symptoms with a low ping!?! It could be the ASR issue mentioned by Tinuva ... or something more sinister?
 
Same problem here, my 4mbps line syncs at 2.8mbps (5km away from exchange) but speedtests fluctuate between 0.4mbps (between about 17h00 till well past 22h00) to 2.1mbps if i do a speed test early morning (about 7h00). this is consistent, every week day. ive ruled out isp since ive tried afrihost capped and uncapped and webafrica capped and uncapped with the exact same pattern.

Pings at all times are never more than 25ms

Im in the Benoni area, Rynfield exchange (011 425), anyone else experiencing this?
 
I had the same problem for about 3 months then I started complaining, TelkomZA managed to get my line moved to another DSLAM and now the problem is sorted. Strange thing was sometimes ping was 30ms but I would only get 0.1Mbps down. After the move line speeds are fine again.

I did however do multitudes of tracerts and some of them indicated 400ms+ on the first hop and other times it was fine.
 
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