pepi
join:2013-02-26
Hartford City, IN | Comcast Jitter What is the usual fix for Comcast Jitter? My 15/2 network is fast but full of Jitter. Causes my IP phone to go nuts. Most Comcast Techs will look at you like your crazy when you tell them there is too much Jitter on the line  |
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| No such thing as a "usual fix".
It could be caused by any number of 500 different things 
That said more details will be needed.
Modem signal levels and noise level.
Pings/trace routes to show ping and hops through your network and comcast etc.
Does the issue happen all the time or only sometimes etc.
Much more details needed |
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pepi
join:2013-02-26
Hartford City, IN | Thanks!  » www.pingtest.net/result/77676230.pngDownstream DCID Freq Power SNR Modulation Octets Correcteds Uncorrectables Downstream 1 1 579.00 MHz 4.55 dBmV 36.17 dB 256QAM 670239166 8 0 Downstream 2 2 561.00 MHz 3.84 dBmV 36.17 dB 256QAM 262305565 26 0 Downstream 3 3 567.00 MHz 4.53 dBmV 36.17 dB 256QAM 225599572 326 832 Downstream 4 4 573.00 MHz 3.72 dBmV 35.97 dB 256QAM 431830172 2409 935 Downstream 5 5 537.00 MHz 3.68 dBmV 35.78 dB 256QAM 404265486 2 0 Downstream 6 6 543.00 MHz 5.06 dBmV 36.17 dB 256QAM 407011167 8 0 Downstream 7 7 549.00 MHz 4.76 dBmV 35.97 dB 256QAM 302197547 15 0 Downstream 8 8 555.00 MHz 3.62 dBmV 35.78 dB 256QAM 327346236 5 0 Reset FEC Counters Upstream UCID Freq Power Channel Type Symbol Rate Modulation Upstream 1 7 31.60 MHz 36.75 dBmV DOCSIS2.0 (ATDMA) 5120 kSym/s 64QAM Upstream 4 1 37.50 MHz 37.50 dBmV DOCSIS1.x (TDMA) 2560 kSym/s 16QAM Status System Uptime: 1 d: 3 h: 49 m Computers Detected: staticCPE(1), dynamicCPE(1) CM Status: Telephony-DHCP Time and Date: Mon 2013-02-25 19:32:00 Interface Parameters Interface Name Provisioned State Speed (Mbps) MAC address LAN Enabled Up 100(Full) CABLE Enabled Up ----- MTA InProgress Down ----- |
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 pflogBueller? Bueller?Premium,MVM
join:2001-09-01
El Dorado Hills, CA
kudos:3 | The signal looks fine. Looks like channel 4 has some minor issues and channel 3 less so, but I don't think those would necessarily cause bad jitter. ~2k uncorrected errors in 24 hours isn't much.
You might want to call support and ask them for your uSNR (upstream signal to noise ratio) value. It should be 30 or higher, the higher the better.
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"I drank what?" -Socrates |
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pepi
join:2013-02-26
Hartford City, IN | Where I work we have an AT&T DSL line and it is so much cleaner than my home Comcast  |
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pflogBueller? Bueller?Premium,MVM
join:2001-09-01
El Dorado Hills, CA
kudos:3 | said by pepi:Where I work we have an AT&T DSL line and it is so much cleaner than my home Comcast
What site is that?
And yes, DSL usually has less jitter than HFC connections. It's just the nature of the beast. Then again, good luck getting more than 18Mbps out of DSL in the US
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"I drank what?" -Socrates |
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 gar187erI do this for a living
join:2006-06-24
Dover, DE
kudos:4 | reply to pepi
jitter and ping will always be higher then dsl, as pflog said.
your test also said 100% of packets arrived in the correct order, so i would question your test.
have you run a sustained ping test?
have you trouble shot anything else in your network yet?
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I'm better than you! |
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 NightfallMy Goal Is To Deny YoursPremium,MVM
join:2001-08-03
Grand Rapids, MI
 ·Comcast
 ·Callcentric
 ·Site5.com
| said by pepi:And yes, DSL usually has less jitter than HFC connections. It's just the nature of the beast. Then again, good luck getting more than 18Mbps out of DSL in the US
said by gar187er:jitter and ping will always be higher then dsl, as pflog said.
Sorry, but these two statements are pure bullcrap.
I can tell you that it depends on the ISP. DSL can have just as many incidents of "jitter" or varying pings as cable can. It depends on your location, ISP, and so on. To say that "jitter will always be higher" on cable connections really is an uninformed statement. Both DSL and Cable are shared mediums, and I have seen varied pings on both cable and dsl providers.
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My domain - Nightfall.net |
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pflogBueller? Bueller?Premium,MVM
join:2001-09-01
El Dorado Hills, CA
kudos:3 | said by Nightfall:Sorry, but these two statements are pure bullcrap.
I can tell you that it depends on the ISP. DSL can have just as many incidents of "jitter" or varying pings as cable can. It depends on your location, ISP, and so on. To say that "jitter will always be higher" on cable connections really is an uninformed statement. Both DSL and Cable are shared mediums, and I have seen varied pings on both cable and dsl providers.
Obviously jitter can be introduced anywhere, and yes if the DSL aggregation point is overloaded it can cause jitter.
I should have clarified that the jitter induced in the "last mile" for HFC will always be worse than the last mile (to the CO/RT) for DSL.
The same could be said for FiOS. But in reality and in most of the cases I've seen (granted, my data points are somewhat dated) DSL usually has less jitter.
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"I drank what?" -Socrates |
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NightfallMy Goal Is To Deny YoursPremium,MVM
join:2001-08-03
Grand Rapids, MI Reviews:
·Comcast
·Callcentric
·Site5.com
| said by pflog:said by Nightfall:Sorry, but these two statements are pure bullcrap.
I can tell you that it depends on the ISP. DSL can have just as many incidents of "jitter" or varying pings as cable can. It depends on your location, ISP, and so on. To say that "jitter will always be higher" on cable connections really is an uninformed statement. Both DSL and Cable are shared mediums, and I have seen varied pings on both cable and dsl providers.
Obviously jitter can be introduced anywhere, and yes if the DSL aggregation point is overloaded it can cause jitter. I should have clarified that the jitter induced in the "last mile" for HFC will always be worse than the last mile (to the CO/RT) for DSL. The same could be said for FiOS. But in reality and in most of the cases I've seen (granted, my data points are somewhat dated) DSL usually has less jitter. I used to do contract work for a couple different ISPs in the past, so you will apologize if I came across harshly. There is this long standing myth that people have about DSL and being "connected to the backbone" which is just false. As you stated, the "last mile" for cable is susceptible to more issues than DSL, but the simple fact of the matter is that they are both shared mediums. I have seen just as many DSL providers have issues as I have cable providers. It really depends on your area.
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My domain - Nightfall.net |
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pflogBueller? Bueller?Premium,MVM
join:2001-09-01
El Dorado Hills, CA
kudos:3 | said by Nightfall:I used to do contract work for a couple different ISPs in the past, so you will apologize if I came across harshly. There is this long standing myth that people have about DSL and being "connected to the backbone" which is just false. As you stated, the "last mile" for cable is susceptible to more issues than DSL, but the simple fact of the matter is that they are both shared mediums. I have seen just as many DSL providers have issues as I have cable providers. It really depends on your area.
No, I understand. I should have qualified my statement. I experienced exactly what you're talking about on SBC DSL back in ~2004-2005. They were bottlenecked at the CO backhaul iirc and it did cause jitter and higher latency.
I'm not sure how susceptible Verizon's FiOS is to this, but at least when I had it in Delaware it was rock solid. My smokeping graphs were amazing compared to Comcast.
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"I drank what?" -Socrates |
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pepi
join:2013-02-26
Hartford City, IN | reply to pflog
»myspeed.visualware.com/indexvoip.php
And yes guys, I've had a tech at my home twice now. Last time he put in a new ARRIS modem. He said his equipment shows my line is fine? He seems to think if I get close to my 15/2 that all is OK. My VOIP and Video streaming is awful. On my phone I can hear the other person very well but they say I'm breaking up. |
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pflogBueller? Bueller?Premium,MVM
join:2001-09-01
El Dorado Hills, CA
kudos:3 | said by pepi:On my phone I can hear the other person very well but they say I'm breaking up.
I would definitely call and ask what your upstream SNR is, given that statement.
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"I drank what?" -Socrates |
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pepi
join:2013-02-26
Hartford City, IN | I will do this ... Thanks! |
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 ptrowskiGot Helix?Premium
join:2005-03-14
Putnam, CT
kudos:4 | reply to pepi
Given that it is your voice breaking up I would tend to think you should set up some qos. Typically that is an upload issue. Are you or the family doing anything bandwidth intensive at the time? |
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| Your voice breaking up? What about your router? Are you on WiFi? Cordless phones, microwaves, other things operating on 2.4 GHz? If dual-band router try shifting to 5.0 GHz for your VOIP and see if that helps. If it does, track down WiFi interference, maybe someone using the same channel next door, or across the street?
Have you cold-booted (not just turned it on/off) your phone recently? (It makes a BIG difference on my iPhone, particularly after upgrading any apps). |
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pepi
join:2013-02-26
Hartford City, IN | reply to ptrowski
I've done this on my wireless router. Doesn't seem to make any difference? |
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| ....and as I think about it now, cold boot both router and modem. Pull plug on both; let modem sit at least 15 seconds (Comcast sez 60 seconds), plug-in and allow to establish sync, THEN plug router back in.
You have probably done this already to clear registers in both modem and router, but just in case not. (Thinking of some of my friends who proudly announce they have been running 120+ days without a reboot, even thought they are DS slow - LOL) |
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ptrowskiGot Helix?Premium
join:2005-03-14
Putnam, CT
kudos:4 | reply to pepi
What VoIP provider are you using? |
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| reply to kdouglas10
If none of that helps, then back to what pflog sez re: S/N ratio. My Comcast tech (who rolled out here 3 times to get my S/N above -37db & finally ran an amplified "homerun" from my distribution box) swears that -37db is a **minimum** signal for reasonably reliable speeds and video streaming. I recognize that jitter is the issue, and some of the early on figures you showed were meaningless to me, but testing using the premium tools on this site shows me with extremely low jitter (now) and consistent down of 18-24MHz (I think downstream is dependent on usage on my block) and 4 MHz upstream while paying for the same speed (15/2) that I think you have.
I feel your pain. Stay on it! |
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