Who Limits My Internet Speed, and How Do They Do It?

[anorlunda]

I've been bothered lately with an excessive number of freezes and dropouts when trying to conduct meetings on Zoom. As many as 10 freezes with 5 dropouts in 15 minutes.

I installed a tool to monitor my connection from my PC. In 4 hours, it gathered the following stats.

General stats​

Online for 0:13:28
Disconnects, today: 23
Availability, today: 98.78%
Downtime, today: 0:02:58
Disconnects, total: 23
Availability, total: 98.78%
Downtime, total: 0:02:58
Latency:

It also shows time plots of Online status and latency. The plot below shows the latency seen by my PC when downloading on my phone. Both share the modem and connection. Watching that plot, I have seen the latency go as high as 8000ms (8s) for periods as long as 30s. The dropouts, mostly seem to be preceded by long latency.

When streaming video, for example Netflix, the buffering seems to mask all such problems and no pauses or dropouts are noticed. But a Zoom meeting must be real time, not buffered.

My modem is Netgear, and it claims to be certified with up to 200 Mbps. My ISP is Xfinity/Comcast and I pay for 75 Mbps. They also offer 200, 400, 800, 1000, and 1200 Mbps speeds.

Here are my questions.

• Does the ISP reprogram my modem to set the speed, or is the speed controlled outside my house?
• When the speed limit is reached, how is it enforced? Increase latency? On/Off toggling like PWM? Something other method?
• I see discussions about "throttling" on the net, and it sounds different than setting the speed. They make it sound like throttling kicks in when a threshold of GB is exceeded. Many of the sources also say that using a VPN allows you to bypass throttling. But I expec that VPN does not allow you to get 1200 Mbps performance when paying only for 75 Mbps. What is the difference between speed control and throttling?

To reduce my problems should I:

1. Forget WIFI for my PC and run an Ethernet cable from PC to modem?
2. Get a better modem?
3. Rent the modem from the ISP?
4. Pay more money to the ISP?
5. Use a VPN?
6. Use a different ISP? (not an option at my location.)

 

[256bits]

#1 might work if there is interference periods with Wifi.

Your ISP could have periods of heavy traffic itself.

Looking at the graph, it seems the latency follows a pattern of lengths 6 seconds, somewhat periodic.
Is that from the ISP's own system packeting, or something internal to your own computer ( or phone ) - ie a system interrupt to an internal system process. ie anti-virus program.
If so #2-4, shouldn't solve the issue.
With a VPN you are still going through your ISP and what you paid for.

Your paid for 75 MPS. You get no more. I imagine your ISP allows only a certain number of packets to be sent to you. If you pay for more speed, you get a higher packet rate.

throttling - since there is only so much wire ( bandwidth ), heavy usage when everyone connects at the same time and wants to download movies exceeding what the ISP can provide through the wire, everyone's speed drops lower so everyone can share equally to some extent. Not deliberate throttling, but due to hardware limitations. An upgrade to the ISP's system would be in order to keep clients more happy. That may or may not be your problem.

 

[Filip Larsen]

You can perhaps try use tracert during periods of latency to see if you can get a fix on what link the latency is introduced. If tracert never reveals the high latency link it may be a protocol or bandwidth problem. That said, bad wi-fi is a very likely candidate for latency, especially if you need to stream data and there is a lot of other active wi-fi access points nearby (as shown when you do a wi-fi search from your computer or mobile phone) or other sources of electronic noise.

 

[jedishrfu]

Also we are getting close to Xmas, kids are getting out of school, people are ordering stuff online, medicare final countdown all happening during the day, nighttime people streaming, kids playing games... so the ISP may be portioning out internet service.

What tool did you use to track internet usage?

The wired approach can rule out wifi issues. I've seen that at home where my wifi turned to crap. Also do you have more than one wifi network. I have an extender for hard to reach wifi home camera connections. However, my machines would periodically connect to the extender network due to some drop out issue with the main network and then not reconnect to the main.

 

[anorlunda]

You can perhaps try use tracert during periods of latency to see if you can get a fix on what link the latency is introduced. If tracert never reveals the high latency link it may be a protocol or bandwidth problem. That said, bad wi-fi is a very likely candidate for latency, especially if you need to stream data and there is a lot of other active wi-fi access points nearby (as shown when you do a wi-fi search from your computer or mobile phone) or other sources of electronic noise.

Thanks. That's interesting.

tracert  physicsforums.com

Tracing route to physicsforums.com [2606:4700:20::ac43:4487]
over a maximum of 30 hops:

  1     3 ms     2 ms     1 ms  2601:881:8480:6a00:a36:c9ff:feb0:3c12
  2    17 ms    10 ms    12 ms  2001:558:40c1:c::1
  3    10 ms     9 ms     9 ms  2001:558:312:6005::1
  4    11 ms    10 ms    11 ms  2001:558:310:d6::1
  5     *       14 ms     *     2001:558:310:93::1
  6    21 ms    23 ms    44 ms  ae-30-ar03.bonitasprngs.fl.naples.comcast.net [2001:558:310:74::2]
  7     *        *        *     Request timed out.
  8    23 ms    24 ms    23 ms  be-3111-pe11.nota.fl.ibone.comcast.net [2001:558:3:64::2]
  9    24 ms    25 ms    74 ms  2001:559::902
 10    22 ms    23 ms    23 ms  2400:cb00:368:3::
 11    22 ms    29 ms    30 ms  2606:4700:20::ac43:4487

Trace complete.

I got this "Request timed out" message 4 times in a row. Naples Florida is in the zone recently hit by Hurricane Ida. That might have something to do with why my problems started recently. I also assume there is nothing I can do to prevent hops from going to Naples.

The one that timed out was this hop from Naples to Miami.
7 * * 23 ms be-33913-cs01.miami.fl.ibone.comcast.net [2001:558:3:354::1]

 

[jedishrfu]

Could you use your cell phone as a hotspot for the zoom meetings? Might be expensive if you go over some monthly data plan though.

 

[Vanadium 50]

My ISP is Xfinity/Comcast

There's your problem. I have them too, and I'd prefer to find a company with better customer service, such as Spawn of Satan, Inc. and.or one more competent. Are the Three Stooges available?

Typically, you are buying a number of "channels". To over simplify, you get ~40 Mb/s per channel. At 75, you probably have 2 channels. When you upgrade your service, they turn more on. Like I said, it's more complicated than that, but that's the idea. Most modems have a web interface, and you can see a) how many channels are running, b) what the error rate (corrected and uncorrectable) per channel is

So if the problem is on the Comcast end, you might see errors or bad channels in the stats.

However, WiFi is more likely to be your culprit. Especially if you are in a congested area.

 

[Tom.G]

Just a FYI.
A somewhat more informative version of "tracert" is "pingplotter." In addition to the tabular data, it plots a latency line graph for each hop.
I've been using the free version for a few decades, there is also a paid version that I know nothing about. A Google search for it works.

Cheers,
Tom

 

[vela]

Use a different ISP?[/S] (not an option at my location.)

You should check out https://broadbandmap.fcc.gov/home to see what's available at your address. I discovered a few options that I never heard about at mine.

 

[anorlunda]

You should check out https://broadbandmap.fcc.gov/home to see what's available at your address. I discovered a few options that I never heard about at mine.

Thanks, that's useful. Here is their answer for my address. My only other option is satellite.

 

[vela]

I got this "Request timed out" message 4 times in a row. Naples Florida is in the zone recently hit by Hurricane Ida. That might have something to do with why my problems started recently. I also assume there is nothing I can do to prevent hops from going to Naples.

The time out could happen simply because that hop doesn't respond to pings. I agree with the others that wifi is the most likely culprit.

That said, I did seen to notice that Zoom connections seemed flakier when I was using cable internet two years ago. Students seemed to get disconnected during class more often, and when in a meeting where I wasn't the host, I experienced occasional pauses and dropouts. I don't recall the same issues when I was using AT&T.

 

[jedishrfu]

It could be due to a Zoom priority scheme servicing hosts more carefully than listeners.

 

[johnbbahm]

Unfortunately latency ties directly to your throughput in bits per second.
How to Calculate TCP throughput for long distance WAN links
If you have a good signal to noise ratio, you could try to increase your TCP window size,
but the larger the carrier, the larger the amount to resend if an error is detected.
if it were me, I would try the direct cable first, that would eliminate the WiFi as a factor.
I do not think the VPN would help, as it will add overhead, and may still go through the same path.
There is a chance that a VPN would not go through the slow area, and your internet point of presents(where you look like you are coming from, has no long latency hops, but it is just a chance.

 

[anorlunda]

Good news. I followed the advice of many in this thread and changed my PC from WIFI connection to Ethernet. After 24 hours of use, zero dropouts, zero slow-downs!!!

Thank you all for the good advice.

 

[Tom.G]

...changed my PC from WIFI connection to Ethernet. After 24 hours of use, zero dropouts, zero slow-downs!!!

So the search universe of problems has been reduced to size three:

1. Computer
2. Router
3. External interference

All a miniverse of their own.
(is that even a word?)

 

[Astronuc]

Forget WIFI for my PC and run an Ethernet cable from PC to modem?

A close friend has a similar problem. The household uses WiFi from the cable modem, rather than WiFi from a router. There are intermittent problems with the WiFi.

We use a Netgear router, which is attached via RJ45 cable to the modem. It seems to work. My son does a lot of streaming, but he's connected via cable. I use WiFi with my laptops/smartphone and cable for desktop.

The same person uses Xfinity/Comcast, and as V50 mentioned that could be a factor.