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kevinds
Premium Member
join:2003-05-01
Calgary, AB

kevinds to Ickerbicker

Premium Member

to Ickerbicker

Re: [AB] Internet jitter high

Business 100 using static IP.



@rustydusty - packet loss test will fail, unless you have Sun's Java installed

rustydusty
join:2009-09-29
Red Deer County, AB

rustydusty

Member

Ahh, yes forgot about that. These are virtual machines, therfore they have never had java installed. Flash is about only thing, and just to do random speed tests.

Talios
@shawcable.net

Talios

Anon

Looks like I spoke too soon, for the past two days my jitter has become much, much worse,




50 ms of jitter makes games pretty much impossible =/

xShades
@bell.ca

xShades

Anon

[BC] North Vancouver here on Shaw 100+ and I'm getting horrible Jitter. Download and upload speeds are fine.

One thing I noticed is that when my modem transmits data on the upstream my latency goes through the roof. It seems that the jitter is connected to transmitting data.

Running a constant ping to the first hop outside of my location I'm getting pings from 9ms to 50ms. Thats horrible line quality and worthless for any type of real time gaming or VOIP.

If I push data on the upstream and watch my ping at the same time it spikes all the way to 150-200ms while the data transfers and then settles down to the horrible jittery base.

I have a tech booked to visit on wednesday the 11th of April I'll post back here if they find anything.
ravenchilde
join:2011-04-01

ravenchilde

Member

said by xShades :

[BC]
One thing I noticed is that when my modem transmits data on the upstream my latency goes through the roof. It seems that the jitter is connected to transmitting data.

Running a constant ping to the first hop outside of my location I'm getting pings from 9ms to 50ms. Thats horrible line quality and worthless for any type of real time gaming or VOIP.

If I push data on the upstream and watch my ping at the same time it spikes all the way to 150-200ms while the data transfers and then settles down to the horrible jittery base.

Yes. Uploading can have a drastic effect on downloading due to the need of TCP to acknowledge the receipt of packets back to the sender. The rising size of buffers on modern routers (an issue called "buffer bloat") has been shown to be aggravating TCPs reaction to upstream congestion.

»netalyzr.icsi.berkeley.edu/

Netalyzer by ICSI was written to check for buffer bloat and a few other issues and is a good tool to run on your network. It will tell you if your router is being an issue.

My apple airport extreme has almost 1M of upstream buffer which is a pretty bad situation for lag/jitter when uploading AND trying to download using TCP.

If netalyzer shows a large uplink buffer on your router, you might want to do some research for a router with less uplink buffer and try that, or bypass your router and run the test again.

You'd also want to then test your jitter again while bypassed or on a non-buffer-bloated router. This will help you find out if the service is the issue, or if TCP ACK packets being buffered because of your uploading is the issue.

It's my opinion that TCP requires a fairly large amount of upstream bandwidth free to have fast and jitter-free downloading.

xShades
@bell.ca

xShades

Anon

ravenchilde,

Thanks for the reply but I think your way off target here.

1. I'm not about to install a java app from the web based on a forum post.

2. The Cisco router I am using is an all on one Router and DOCSIS3 modem from Shaw.

3. Small ICMP packets bouncing off a shaw core router one hop from my modem should have a jitter of 1-5ms tops.

4. Light use of the up-channel should not spike ICMP pings to 150ms from 15ms.

5. The router was working fine up until a few days ago.
ravenchilde
join:2011-04-01

ravenchilde

Member

said by xShades :

ravenchilde,

Thanks for the reply but I think your way off target here.

1. I'm not about to install a java app from the web based on a forum post.

Yup. Do what you want.

xShades
@shawcable.net

xShades

Anon

Shaw runs a network that it sells to its customers.

If that network is in part or fully overloaded in that it causes high latency high jitter communications it will have 2 effects.

1. A huge increase in support calls. Support calls cost money.
2. People will leave and try another service.

I'm giving Shaw the opportunity to retain my business by fixing my issue. If they wont or cant then I move on, no big deal.

In my instance I believe its just some EMI or mis-configured modem that's causing the random jitter. My bandwidth is fine, if it was an over loaded core router I would expect to see a reduction of bandwidth along with the jitter, that is not the case.

DOCSIS 3 modems up-channels are notoriously difficult to tune for a clean signal. I'm hoping the tech that comes today can clean up mine and get rid of this nasty jitter.
ravenchilde
join:2011-04-01

ravenchilde

Member

said by xShades :

Shaw runs a network that it sells to its customers.

If that network is in part or fully overloaded in that it causes high latency high jitter communications it will have 2 effects.

1. A huge increase in support calls. Support calls cost money.
2. People will leave and try another service.

I'm giving Shaw the opportunity to retain my business by fixing my issue. If they wont or cant then I move on, no big deal.

In my instance I believe its just some EMI or mis-configured modem that's causing the random jitter. My bandwidth is fine, if it was an over loaded core router I would expect to see a reduction of bandwidth along with the jitter, that is not the case.

DOCSIS 3 modems up-channels are notoriously difficult to tune for a clean signal. I'm hoping the tech that comes today can clean up mine and get rid of this nasty jitter.

I still think you should look into bufferbloat as it sounds a lot like your situation with uploading and jitter/ping time.

Today's Security Now episode (twit.tv) had a Q&A section covering this exact scenario.

Have you tried testing it with your modem/router in bridged mode and directly connected?

Died
@shawcable.net

Died

Anon



I'm suffering 5% packet loss suddenly with Shaw....not happy Has made online gaming unplayable, amongst other problems.

XT0RT
S3x, Drugs, War
join:2001-07-28
Edmonton, AB

XT0RT

Member



Must be a noise issue on the node. No problems where I am at.