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Morac
Cat god

join:2001-08-30
Riverside, NJ
kudos:1
Reviews:
·Comcast

2 edits

[Connectivity] Packet loss

Today I'm noticing about 2 to 6% packet loss which is annoying since I wanted to get some COD:MW2 gaming in today. I didn't have a chance to play yesterday when my connection was working fine.

I called Comcast and the person told me that their tool indicated I had 2% loss and she recommended I get a new modem. I told her the modem has been working fine and asked her to check my upstream signals. She responded that my upstream signals were the same as my downstream signals. From that I determined she really didn't know what she was talking about and scheduled a tech. Unfortunately my appointment is on Wednesday and it's a 4 hour window (which sucks). Before she hung up she reset my modem which didn't help.

This isn't the first time I've had problems in this area, though it has been a while (last summer probably was the last time). I think the heat has something to do with it.

Here's a line quality test:

»/linequality/nil/2647783

Some ping tests:





Ping statistics for 68.x.x.1 (my gateway):
Packets: Sent = 1298, Received = 1267, Lost = 31 (2% loss)
Approximate round trip times in milli-seconds:
Minimum = 0.1 ms, Maximum = 42.4 ms, Average = 12.1 ms


Here's the modem's signal info which look fine to me:

Downstream
Freq/Power: 723.000 MHz -9 dBmV
Signal to Noise Ratio: 35 dB
Modulation: QAM256
Upstream
Freq/Power: 23.200 MHz 46 dBmV
Channel Type: DOCSIS 2.0 (ATDMA)
Symbol Rate: 5120 kSym/sec
Modulation: QAM16

My guess is it's an upstream signal problem, but the person on the phone said my upstream signals were good and I called back and got another person who also confirmed the upstreams signals were good though she couldn't see the upstream SNR since she said it's not viewable any more.

Any other guesses as to what it is?

--


The Comcast Disney Avatar has been retired.


gar187er
I do this for a living

join:2006-06-24
Dover, DE
kudos:4

up stream SNR, or it could be your at -9 downstream.....getting a tech out to get your downstream signal better will regardless...hell be able to check your snr via his handheld device....


marc105421

join:2010-05-26
Jacksonville, FL
reply to Morac

try the m-lab jitter test at broadband.gov. jitter is not good for gaming.


marc105421

join:2010-05-26
Jacksonville, FL

also, i don't want to overshadow what gar187er said and the m-lab test should only be used as a guide. maybe ask the tech if he can see jitter on your line using his signal meter.



beachintech
There's sand in my tool bag
Premium
join:2008-01-06
kudos:5
reply to marc105421

Jitter is the least of his concerns until the signal issues / packet loss are corrected.
--
Tech at the Beach.
I speak for myself, not my employer.


marc105421

join:2010-05-26
Jacksonville, FL

maybe jitter will lead comcast to the problem.



Morac
Cat god

join:2001-08-30
Riverside, NJ
kudos:1

1 edit
reply to Morac

Not getting any better:



gar187er
I do this for a living

join:2006-06-24
Dover, DE
kudos:4
reply to marc105421

said by marc105421:

maybe jitter will lead comcast to the problem.
takes too long to measure jitter...most techs arent concerned with it, because too many variables go into jitter...unless your communicating with the cmts...

rf, and snr is key...without those, who cares about jitter

marc105421

join:2010-05-26
Jacksonville, FL

his signal specs are within jlivingoods range. although his area maybe different. they don't seem like they would be causing that much packet loss. jitter is always a concern.



Morac
Cat god

join:2001-08-30
Riverside, NJ
kudos:1
Reviews:
·Comcast
reply to Morac

Well it seems to have mostly fixed itself as of 9 PM (EDT). It's only losing about 3 pings out of 1500 which is less than 1%. It's still not fixed completely though so I'm going to keep my appointment. Also it gets worse again.

Here's the latest ping test:


Not as good as as it was Saturday though, the day before I started having problems:


Here's my current signals:


Downstream
Freq/Power: 723.000 MHz -5 dBmV
Signal to Noise Ratio: 35 dB
Modulation: QAM256
Upstream
Freq/Power: 23.200 MHz 45 dBmV
Channel Type: DOCSIS 2.0 (ATDMA)
Symbol Rate: 5120 kSym/sec
Modulation: QAM16


Note that my downstream signals have always gotten worse in the summer. In the winter it's around 0 or even +1. In the summer (or at least when it's hot outside) it gets down to -10. That's the way it's been the last 7 years I've been at my house.

--

The Comcast Disney Avatar has been retired.

marc105421

join:2010-05-26
Jacksonville, FL

the pingtest.net\ookla jitter test hasn't been very accurate\sensitive for me(your jitter readings might actually be higher).
you might be causing game lag even though you might not be experiencing much lag yourself.
if your worried about jitter in the future(jitter and packet loss can be closely related), try testing with the m-lab jitter test at broadband.gov\



Morac
Cat god

join:2001-08-30
Riverside, NJ
kudos:1
Reviews:
·Comcast

4 edits

I'm a lot more worried about the packet loss than the jitter. Jitter is dependent on the path your packets take through the Internet. Comcast has no control over that.

I'm worried about the packet loss to my first hop (gateway) which is entirely within Comcast's control.

It looks like it's back, despite the downstream signals being good:




Pinging gateway [68.x.x.1] with 1460 bytes of data every 1 ms:

Ping statistics for 68.x.x.1:
Packets: Sent = 299, Received = 272, Lost = 27 (9% loss)
Approximate round trip times in milli-seconds:
Minimum = 9.7 ms, Maximum = 34.8 ms, Average = 12.7 ms

marc105421

join:2010-05-26
Jacksonville, FL

if you have jitter to that gateway. that gateway is gonna have problems processing your signal.



Morac
Cat god

join:2001-08-30
Riverside, NJ
kudos:1
Reviews:
·Comcast

1 recommendation

said by marc105421:

if you have jitter to that gateway. that gateway is gonna have problems processing your signal.
I think you are too hung up on jitter. Dropped packets are a lot more detrimental than jitter. It's likely the dropped packets that are causing the poor jitter values.
--

The Comcast Disney Avatar has been retired.

marc105421

join:2010-05-26
Jacksonville, FL

you maybe dropping packets because of jitter and yes i'm hung up on jitter. just trying to help you and thought you should know about the m-lab jitter test vs. the pingtest.net\ookla test. good luck with your problems.


marc105421

join:2010-05-26
Jacksonville, FL
reply to gar187er

said by gar187er: takes too long to measure jitter...
____

how long does it take to measure jitter(using a signal meter)?



Morac
Cat god

join:2001-08-30
Riverside, NJ
kudos:1
Reviews:
·Comcast

2 edits
reply to marc105421

The broadband.gov test doesn't measure packet loss which is more important to gaming (and other Internet applications) than jitter.

Jitter just tells you how much of a variation there is between pings. Packet loss tells you how many pings are being dropped. Dropped pings makes measuring ping variation inaccurate.


--


The Comcast Disney Avatar has been retired.


marc105421

join:2010-05-26
Jacksonville, FL

when jitter buffers can't handle a bad signal, i believe packets can be lost. if you have a bad signal and you cross another "bad area" then more problems can arise possibly due to all of the proccessing that must be done.
jitter is a major problem to gaming.



beachintech
There's sand in my tool bag
Premium
join:2008-01-06
kudos:5

said by marc105421:

jitter is a major problem to gaming.
Actually it's not as bad as packet loss. As explained, jitter is a normal part of Wide Area Networking. Your PC, Game Server, and everything in between is designed to compensate for this. If the packets never leave your home or get lost in transit, this makes the game experience problems that can't always be overcome quickly enough. You will see problems with packet loss. You most likely won't notice anything with moderate amounts of "jitter" alone.
--
Tech at the Beach.
I speak for myself, not my employer.


Morac
Cat god

join:2001-08-30
Riverside, NJ
kudos:1
Reviews:
·Comcast
reply to marc105421

With both higher jitter and latency, packets can be lost for certain applications that expect packets to be in order such as VOIP or gaming or the like (all which mostly use UDP). The jitter would have to be quite high though.

Ping tests don't care about the order the pings are received. Pings (ICMP) are simply returned when they are received. While jitter can be measured using pings, jitter won't cause ping packets to be dropped.

All of that is moot though. As you can see from my last test. The jitter was 3 ms, which is very good, despite the fact that 2% of the packets were dropped.
--

The Comcast Disney Avatar has been retired.



Morac
Cat god

join:2001-08-30
Riverside, NJ
kudos:1
Reviews:
·Comcast

2 edits
reply to Morac

Edit: Apparently it is also affecting Comcast digital voice. I'm talking to someone on the phone and they said I'm breaking up (like I'm on a bad cell). I can hear the person fine though.

My modem is reporting "No Ranging Response received - T3 time-out" errors though.
--


The Comcast Disney Avatar has been retired.


marc105421

join:2010-05-26
Jacksonville, FL
reply to beachintech

thanks beachintech. but congestion can increase moderate amounts of jitter to unwanted levels also.

morac, you keep posting your ookla jitter scores(i feel the ookla test isn't very sensitive).


marc105421

join:2010-05-26
Jacksonville, FL

3 edits

.


marc105421

join:2010-05-26
Jacksonville, FL
reply to Morac

said by Morac: While jitter can be measured using pings, jitter won't cause ping packets to be dropped.
___

i'm not sure thats true


marc105421

join:2010-05-26
Jacksonville, FL

and also jitter levels don't have to be that high to affect gaming.


marc105421

join:2010-05-26
Jacksonville, FL

google "Extreme 50 questions". i think it might help you.


marc105421

join:2010-05-26
Jacksonville, FL

i'm sry there's another thread with that name, it appears. its the thread started by petes67bird.



EG
The wings of love
Premium
join:2006-11-18
Union, NJ
kudos:9
reply to marc105421

said by marc105421:

jitter is always a concern.
You seem fixated on jitter (no offense bud) ! Jitter is an ever present part of cable based broadband...

marc105421

join:2010-05-26
Jacksonville, FL

no offense to you but i don't think you are very concerned about jitter. jitter is a major problem to gaming and thats all i'm really concerned about. i really don't even care about game lag(other people do).



EG
The wings of love
Premium
join:2006-11-18
Union, NJ
kudos:9

said by marc105421:

no offense to you but i don't think you are very concerned about jitter. jitter is a major problem to gaming and thats all i'm really concerned about. i really don't even care about game lag(other people do).
Try a different transport medium then...

Don't even go on the internet at all...

This is a always an issue for any online gaming...

Don't game online..