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gar187er
I do this for a living

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

Re: momentary internet issues-help.

no hsi only modem has a battery backup.
--
I'm better than you!


FirebirdTN

join:2012-12-13
Brighton, TN
kudos:1

Its an eMTA. I need it as comcast also carries my home phone service.

It has a removable cover and place for battery....just no battery inside!

-Alan


FirebirdTN

join:2012-12-13
Brighton, TN
kudos:1
Reviews:
·Comcast

Feel like I'm talking to myself here, but in case anyone is following my thread...

Its only been a couple hours, but so far no dropouts.

I have noticed something quite odd though...In my screenshots of "pingplotter" on the previous page, you can see just before the 100% packet loss, the pings start to shoot up kind of high...

Well, I happen to notice it coincides with my wife's iPad usage.

With the temporary rented modem I got, I told her to "break the internet", and I notice when she is on it, the pings shoot up to over 500ms, BUT...I do not get any dropouts.

Could just be my imagination, but it almost seems like the iPad is the one thing I can rely on to kill my connection temporarily. However, if you look at the multiping screenshot on the previous page, you can see my router handles it without breaking a sweat. Its almost like the ipad overwhelms the modem. Odd.

-Alan



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

The only thing it would be overwhelming, is your router. It's either broken or your router sucks. The modem is just a bridge.


FirebirdTN

join:2012-12-13
Brighton, TN
kudos:1
Reviews:
·Comcast

3 edits

Click for full size
Click for full size
Beachintech: The router is actually a business class firewall. And if you look at the screenshots on the preceding page you will see the high pings are *past* the router.

Matter of fact, this is my router:

»www.newegg.com/Product/Product.a···33181137

As far as "it sucks", there are plenty of positive reviews that would seem to contradict your assessment. As far as "its broken", I have tried my old standby "linksys", and it behaved the same. I also tried an IDENTICAL USG50 with the same results as well. Three routers, all behave the same...broken? I think that is a big assumption on your part.

I do appreciate the attempt to help, I really do. But based on the information I have provided, I truly believe you are coming to the wrong conclusions. Its NOT MY ROUTER. You might have missed my statement on the preceding page where I mentioned I work in Radio/TV as an engineer. More specifically, not only do I take care of the audio/video gear, but I also am the "IT department" (yes, we are terribly understaffed!). I won't bore you with credentials, as I don't have any. I'm not certified in any area with paper backing. I am self-taught. I do NOT claim to be an expert, but do understand, I have setup countless DSLs, Fiber, T1s, long haul microwave wireless networks (20+miles), Audio-over-IP codecs, etc, etc, etc.

The one area I do lack in experience is cable. I think we have one cable internet connection down in Mississippi.

Just because I am relatively new with a low post count, and live in Tennessee, please don't think I am completely clueless. However, due to my lack of experience with cable internet, that is precisely why I reached out to this forum for a helping hand. That and to see if anyone could say "oh yeah, ive see that before, you need to do x".

Of course, it isn't without irony that of all the networks I have setup and maintained across the country, it is MY PERSONAL one that has to be the unreliable one.

-Alan

-Edit- Why the hell not...here is my setup in my closet, taken on my crappy camera phone.


gar187er
I do this for a living

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

no two cable problems are ever the same.

its still time hook up direct with two seperate machines to your modem, to rule out wires, nics, routers, everything.

thats the only way to eliminate it all.
--
I'm better than you!


FirebirdTN

join:2012-12-13
Brighton, TN
kudos:1
Reviews:
·Comcast

said by gar187er:

no two cable problems are ever the same.

its still time hook up direct with two seperate machines to your modem, to rule out wires, nics, routers, everything.

thats the only way to eliminate it all.

Boy, you got that right about no two problems the same. I swear I only get the difficult ones.

In all honesty, I did hook one PC directly up to the modem, only for about 2 half days, and experienced no issues.

Normally, I would definately say that is a valid test to rule out equipment on my end; however in my particular case, I do not think that is sufficient to come to a definative conclusion. I am sure most people will disagree with me, but by hooking one PC direct to the modem, it allows for 2 possibilities:

1) If no problems are experienced, it would mean I have an issue with my equipment somewhere.

2) If no problems are experienced, it could also mean that I just can't simulate our internet usage with a single PC, and therefore can't really come to any real conclusion.

Its always possible, however rare, that my modem is crapping out during high demand in such a way as to not lose sync, but just stop passing data for brief periods of time. Rare indeed, but that really is starting to look to be the case.

As far as trying different equipment, I only have two model routers to choose from. I do have 5 wrt54gls and 2 usg50s available to me. It could be some weird incompatibility, but I really doubt it.

I have already tried 3 different routers, all with the same results.

As some users have suggested, I think ping plotter/multiping tells the REAL story of what is happening.

So far, no issues at all with the new modem. I'll give it two weeks, and if I am still problem free, I will then see about getting mine repaired/replaced.

-Alan

russgold

join:2012-06-08

I have this same issue.

Pingtest.com gives me an A
Speedtest.net gives me an A+
Shaperprode never shows issues

But I randomly will experience my internet quit working for 10-20 seconds it appears to be random.

I also have an iPad 2 on the network what version is your iPad? I've almost narrowed it down to that device it seems to do it both routers I've had.


FirebirdTN

join:2012-12-13
Brighton, TN
kudos:1
Reviews:
·Comcast

said by russgold:

I have this same issue.

Pingtest.com gives me an A
Speedtest.net gives me an A+
Shaperprode never shows issues

But I randomly will experience my internet quit working for 10-20 seconds it appears to be random.

I also have an iPad 2 on the network what version is your iPad? I've almost narrowed it down to that device it seems to do it both routers I've had.

Ours is an iPad3. Your issue could be similar to mine, or completely different. Its hard to say. But the single most helpful thing I found to troubleshoot this issue was Pingplotter and Multiping as suggested earlier in the thread. Well worth the $44 I think it was that I paid for them together.

-Alan

Jenjo

join:2013-03-06
Independence, MO
reply to FirebirdTN

I've had similar issues for a while (though I don't own an ianything), and happened to run a bunch of pings and a tracert during a sustained episode tonight. Thought it might help. If you just want the results, skip ahead.

My info:
1) I'm in Independence, MO.
2) I have intermittent connection issues, where the internet will all but drop for several seconds to around a minute, then go back to normal.
3) It happens at any time, there has been no pattern that I could find.
4) I have been through 4 modems and three routers to find a setup that my work phone will function properly on, but have never resolved the intermittent signal issues. My current modem is a Motorola SB6141, the firmware it lists is SB_KOMODO-1.0.6.8-SCM01-NOSH.
5) I have a Belkin N600 DB router. My computer on which I test, work-supplied VPN phone, and a switch the rest of the house uses are all plugged into the router, which is plugged into the modem.
6) I run AVG free 2013, build 2899 - no other antivirus or firewall.
-I'm on the highest speed Comcast will provide, which is simply labelled as "Internet Service" for $64.95, with a $10 addition tacked on for "Blast! Internet service" that supposedly is giving me a speed boost.
-Speeds normally test at 35/6ish, one I just ran is »stage.results.speedtest.comcast.···9602.png. On rare occasion I've caught it in the middle of a fit where the speedtest showed an effect, such as this: »stage.results.speedtest.comcast.···6932.png
-I run Chrome.
-The indicator lights on my equipment are normal throughout. I have: Power, upstream, downstream, web (all solid) and connection activity (always blinks orange)
-My current default gateways are 8.8.8.8 and 8.8.4.4. I've also used the default Comcast supplies (though I can't remember it offhand, 70 something each part) and an alternate they provided, 4.4.4.4 & 4.4.2.2.

It sort of freaked out when I was copying everything from the command prompt, but here are the results (that didn't get pushed out of the log) of a dozen pings and a tracert I ran tonight:

C:\Users\Jen>ping 209.244.0.4

Pinging 209.244.0.4 with 32 bytes of data:
Request timed out.
Request timed out.
Request timed out.
Reply from 209.244.0.4: bytes=32 time=1167ms TTL=53
Ping statistics for 209.244.0.4:
Packets: Sent = 4, Received = 1, Lost = 3 (75% loss),
Approximate round trip times in milli-seconds:
Minimum = 1167ms, Maximum = 1167ms, Average = 1167ms

C:\Users\Jen>ping 208.67.222.222
Pinging 208.67.222.222 with 32 bytes of data:
Reply from 208.67.222.222: bytes=32 time=936ms TTL=52
Reply from 208.67.222.222: bytes=32 time=55ms TTL=52
Request timed out.
Request timed out.

Ping statistics for 208.67.222.222:
Packets: Sent = 4, Received = 2, Lost = 2 (50% loss),
Approximate round trip times in milli-seconds:
Minimum = 55ms, Maximum = 936ms, Average = 495ms

C:\Users\Jen>ping www.comcast.net
Pinging a1526.dscg.akamai.net [208.47.254.73] with 32 bytes of data
Request timed out.
Reply from 208.47.254.73: bytes=32 time=2863ms TTL=50
Request timed out.
Reply from 208.47.254.73: bytes=32 time=2098ms TTL=50

Ping statistics for 208.47.254.73:
Packets: Sent = 4, Received = 2, Lost = 2 (50% loss),
Approximate round trip times in milli-seconds:
Minimum = 2098ms, Maximum = 2863ms, Average = 2480ms

C:\Users\Jen>tracert 8.8.8.8

Tracing route to google-public-dns-a.google.com [8.8.8.8]
over a maximum of 30 hops:
1 1 ms 1 ms 1 ms 192.168.2.1
2 * 425 ms * 69.242.128.1
3 700 ms * 2477 ms te-9-2-ur02.independence.mo.indepen.comcast.net[68.87.234.229]
4 * * 1239 ms te-8-4-ur01.independence.mo.indepen.comcast.net[68.87.234.17]
5 * 9 ms * te-4-3-ar01.independence.mo.indepen.comcast.net[68.87.234.9]
6 * * 23 ms te-5-2-0-12-cr01.350ecermak.il.ibone.comcast.net [68.86.92.1]
7 1040 ms * 30 ms pos-1-3-0-0-pe01.350ecermak.il.ibone.comcast.net [68.86.86.158]
8 * 3281 ms * as15169-4.350ecermak.il.ibone.comcast.net [66.208.233.142]
9 * 20 ms 20 ms 209.85.254.130
10 * * * Request timed out.
11 42 ms 40 ms * 72.14.232.70
12 48 ms * 430 ms 72.14.238.16
13 * * 45 ms 72.14.232.21
14 * 41 ms 43 ms google-public-dns-a.google.com [8.8.8.8]

Trace complete.

The pings pretty much all looked the same - it's the trace that holds what looks to be interesting info, since it appears that everything goes to hell as soon as it leaves the home network. Hope this helps.


FirebirdTN

join:2012-12-13
Brighton, TN
kudos:1
Reviews:
·Comcast

Jenjo-

I follow everything you said, but your "gateway" addresses look a little odd to me. Are you sure you didn't mean DNS entries?

In any case, its very difficult to tell anything based on your pings and tracert results. But from the looks of it, your issue is different than mine, as I always have at least 10 straight timeouts in a row during my disruptions. I never have intermittent alternating timeouts and replies right together.

You could have a signal issue, cabling issue, it could be any number of things. I will gladly help you out the best I can, but it might be better to start a new thread, and start "from the top", and let those more knowledgeable than myself take a peek at your modem stats.

-Alan


Jenjo

join:2013-03-06
Independence, MO

Probably. It's been almost a decade since I've had to troubleshoot connection issues beyond the normal occasional outage, and the most technical term I've heard used by anyone I've talked to about all of it is "ping." I've managed to get to the point where I don't have issues with my connection to work getting disrupted anymore, so I'm content with my situation (though I very much appreciate the offer ). Mostly I've just had some of the running ping tests I've done look exactly like what you posted earlier in a repeating pattern. My intent in posting was simply to add support to the assertion that the problem isn't with your home network.



SmokChsr
Who let the magic smoke out?
Premium
join:2006-03-17
Saint Augustine, FL
reply to FirebirdTN

I'll bet what you are looking at is noise getting into the cable blocking your upstream traffic. I've been fighting this with Comcast for some time with one of my clients. Comcast knows it's a problem and knows what the problem is they just haven't been able to correct it yet. Remember on cable the upstream and down stream traffic take 2 separate paths, so your downstream traffic could be just fine while your upstream traffic is lost. In the case I'm dealing with I was sending UDP traffic that once it was lost there was no recovery.


FirebirdTN

join:2012-12-13
Brighton, TN
kudos:1
Reviews:
·Comcast

SmokChsr-

Opps. Saw your reply, and thought you were directing it at JenJo; didn't realize it was for me.

I've definitely made this harder than it needed to be (going on 3 months, and this 2 page thread), but part of it was the intermittent nature of my issue. The other thing that made me second guess myself is the problem showed up shorty after [but not immediately after] putting in the new router. My first thought was, bad router. Then I tried a second. Same deal. So I then thought maybe some incompatibility, and put my "old trusty" back in, and it behaved the same.

After that, since it seems like downstream wasn't affected (once a netflix movie was started, it was never interrupted), I came to the same conclusion as you: upstream problem. When I saw the frequency used for the upstream, I did have a brief crazy thought: The upstream frequency is right in the Citizen's Band radio spectrum. Although not as popular anymore, down here in the South, there are a few people with really high powered CB radios (were talking running thousands of watts), that often times have butchered modifications that splatter all up and down the band, that if near enough to Comcast cabling, could actually cause some issues!

But the way my particular issue behaves, that isn't it. Although my issue seems random, the service disruptions always last about the same length of time.

Again, its still way too early to tell, but so far, it looks like the modem just couldn't handle the load. Last night we had on-line gaming going, two iPads, a Netflix stream [yes, my house is a zoo], and I was on the PC (running pingplotter while websurfing), and did not have any dropouts, or even a single lost packet.

-Alan


NanbanJim

join:2013-03-05

I am unsurprised that Netflix doesn't hiccup, since it buffers video for just this sort of occurrence.

One thing I've found that can cause "random" intermittency is Stateful Inspection being turned on in some modems. SPI is great... if it's implemented well. Most consumer modems with SPI favour false-positives... and do NOT like VPNs. In the same vein, you might ensure the provider turns off any firewalling they may have given you without telling you. Happens to my business clients all the time. If you've got a ZyWall, after all...

The last thing, for all the people having this random problem... Get pings and traceroutes to your modem from a remote location when this happens. If you have a smartphone, that's a "remote location." If you can ping the modem's public IP address from the interwebz, then you can be pretty sure it's a router issue. If you can't... then it's likely a provider issue.



plencnerb
Premium
join:2000-09-25
Carpentersville, IL
kudos:3
reply to FirebirdTN

FirebirdTN See Profile,

After reading your thread, I wanted to throw another suggestion out there. You mention that your problem may be that your modem may not be able to handle the load that the people in the house are putting on it. I don't think your problem is the modem, but the routers you are using.

To help show this point, I want to reference an article that was posted to the front page by ryan711 See Profile back on Tuesday, March 20, 2012.

The article was called "Exploring DIY Linux Router Distros: Enterprise Power for Home Users". Here is a link for that article

»Exploring DIY Linux Router Distros

In the opening statements, ryan711 See Profile has the following to say (bold added by me)

quote:
Router lockups have been a problem for me ever since I got my first 802.11G Router in 2004. Since then, we've seen companies roll out supposed "power user" routers or routers meant for "gamers," but for some reason not a single one has alleviated the problem of having to reset the router after running for a few days. After my new "gaming" router locked up while refreshing a server list for a multiplayer game, it was the last straw and I began searching for something a little more robust.

It appears to me that your issue may be related to your router hardware itself, and not your cable modem, or any of the connected devices. You seem to have a lot going on, as far as physical network traffic, and a "store-bought" router may not be good enough.

Depending on your experience level, and the access you have to older hardware, you may want to check out the options outlined in that thread, and see if that solves your problem.

Going along with that article, RyanC6 See Profile wrote one that goes into a bit more detail to setup additional networks for gaming and wireless. That article also appeared on the front page as a news item back on Monday, May 07, 2012. The link to that is below

»Securing Your Home Network Utilizing Multiple Network Interfaces

Again, not saying this is your problem, but it appears to me that it might be the issue, and could potentially be another option for you to look at to solve your problem.

--Brian
--
============================
--Brian Plencner

E-Mail: CoasterBrian72Cancer@gmail.com
Note: Kill Cancer to Reply via e-mail

FirebirdTN

join:2012-12-13
Brighton, TN
kudos:1
Reviews:
·Comcast

plencnerb-

Its still possible to be my equipment [anything is possible], but maybe my posts are too long and you are missing some key information...

Or maybe my logic is faulty?

They say a picture is worth a thousand words. The screenshots in the preceeding page show that the router is still passing traffic [ICMP traffic anyway], even through a service disruption. Doesn't seem to be the router. Besides, its an SMB grade firewall, not some $50 home router.

One more *key* piece of info I have neglected to post, and I only found this out *after* purchasing pingplotter standard/multiping:

I CAN still access my modem's configuration/status page during service disruptions, but CANNOT access any WEB services during these disruptions.

-Alan



plencnerb
Premium
join:2000-09-25
Carpentersville, IL
kudos:3

said by FirebirdTN:

They say a picture is worth a thousand words. The screenshots in the preceeding page show that the router is still passing traffic [ICMP traffic anyway], even through a service disruption. Doesn't seem to be the router. Besides, its an SMB grade firewall, not some $50 home router.

After I made my post, I did see the picture you are talking about. So yeah, I agree that the router you have is not some store-bought one from Best Buy or Wal-Mart. You have a business-grade router there.

said by FirebirdTN:

I CAN still access my modem's configuration/status page during service disruptions, but CANNOT access any WEB services during these disruptions.

Logic would show that if you can get to the modem, but not the internet during the outage, then the "issue" would be with the modem itself, as traffic is able to pass from the device you are testing on, through the router, and to the modem, but no further.

With that bit of information, I would tend to believe your problem is with the modem, or something beyond that (house wiring, splitters, etc, etc). But, from reading your posts, you have the background and experience on how to set all that up, so it would really be odd if that was the issue. Not to mention, you probably have already checked all that many times over.

--Brian
--
============================
--Brian Plencner

E-Mail: CoasterBrian72Cancer@gmail.com
Note: Kill Cancer to Reply via e-mail

FirebirdTN

join:2012-12-13
Brighton, TN
kudos:1
Reviews:
·Comcast

said by plencnerb:

... Not to mention, you probably have already checked all that many times over.

--Brian



-Alan

FirebirdTN

join:2012-12-13
Brighton, TN
kudos:1
Reviews:
·Comcast

I know I said I would give it two weeks, but I decided to go ahead and at least swap my emta (DOCSIS 3.0) out at Best Buy since I have been problem free since renting one (DOCSIS 2.0) from Comcast.

The problem: I can't find any. Best Buy did at least let me return it even though it was almost 8 months old (for store credit only/no refund). However, no Best Buy in my district has any, and the store manager said they cannot even order them.

Did comcast stop selling emtas thru Best Buy?

-Alan


FirebirdTN

join:2012-12-13
Brighton, TN
kudos:1
Reviews:
·Comcast

1 edit

Leave it to ME to find the most difficult problem imaginable. I should probably start a new thread, but I will try to keep it all in this one.

So after over a week problem free, I decided it was time to get Comcast to replace the DOCSIS 2.0 loaner with a DOCSIS 3.0. That was quite an experience in itself. I will spare those stories.

So finally after TWO full weeks problem free I *finally* get my DOCSIS 3.0 emta. This time an Arris TM822 (I had initially purchased a TM722 from Best Buy when I became a Comcast customer last year).

Within MINUTES of my wife using her iPad on the new TM822, the problem is BACK.

This is really starting to look like some issue with channel bonding, as I had ZERO problems when I was using the DOCSIS 2.0 emta, which looks like only used a single upstream, and a single downstream channel.

So....does anyone have any thoughts on where I go from here besides throw these emtas out my car window on the way to work?

-Alan


FirebirdTN

join:2012-12-13
Brighton, TN
kudos:1
Reviews:
·Comcast

Another update:

I think I have *finally* found the problem, but before I get into it:

I have a supervisory visit this coming Tuesday. Got a call from him yesterday. He is monitoring my connection, so we will see if he had any success in seeing these "outages". Unfortunately, his tester can only check it once every 5 minutes, so it may not be enough for him to see them. We will see.

Anyway, it really is starting to look like I am suffering from "Bufferbloat". Its just a SWAG, but my symptoms very much mimic bufferbloat's behavior, especially considering my outages always occur during high demand, and my pings get progressively higher.

Tonight I will set up my router to throttle my bandwidth *just* below my actual "shaperprobe" throughput levels, and test again. Last night, the wife got on her ipad, and I had over 10 45second outages in less than 1 1/2 hours.

Once I impletement traffic shaping on my router, if the issue goes away, then I will know for certain it is indeed bufferbloat, and I will update this thread accordingly for anyone stumbling on it from a search.

-Alan


FirebirdTN

join:2012-12-13
Brighton, TN
kudos:1
Reviews:
·Comcast

After three LONG months my issue is finally resolved. The problem was indeed bufferbloat in the emta. I wish I could find detailed technical specs on the three emtas I have had hooked up these past few months, but based on what I have seen, the newer the model, the worse the issue [the current Arris TM822g I have in operation now was actually suffering from even longer durations of packetloss].

A really good "one pager" is here:

»www.bufferbloat.net/projects/blo···calIntro

I set my router up to limit my bandwidth to just *slightly* under my measured throughput to keep from overloading the modem's upload buffer. I told my wife do her best to "break the internet". Not only did it work flawlessly with no outages or packet loss, but now even when she is on it, the maximum latency I have seen with pingplotter for the entire evening to the first hop has been 76ms, and that is even when she is on it, doing the exact same things that she was before when I suffered horrible latency [sometimes close to 3 full seconds] before it eventually started causing 100% packet loss.

I will need to give it another few days to be on the safe side, but I am now about 99.9% convinced that is what it was. After implementing traffic shaping in my router, everything is so much better, and I no longer get any dropouts.

I am still keeping my tech visit Tuesday, if nothing else just to see how to go about getting another customer owned emta, since I returned mine to best buy and can't find another.

But unless something radically changes, this will be my final post in this thread.

To those that offered constructive advice and pointing me in the right direction, you have my sincere thanks [Netfixer, switchman, and a couple others].

To those that suffered "tunnel vision", and completely ignored the logic of my test results-A piece of advice: Every problem is unique. Just because you have seen something before 99 times, does not mean its going to be the same thing the 100th time.

One last note regarding troubleshooting issues like this: I know its generally considered common practice to hook one PC directly to a modem for troubleshooting purposes; but alot has changed in the last 10 years. It is very difficult to duplicate an entire network's load on a modem with one PC, so just because someone doesn't experience any issues with a PC connected directly to the modem, doesn't necessarily prove anything. I believe its still a valuable troubleshooting aid, but depending on the issues and circumstances, I would not lay as much credence in the results of that test as I would have 10 years ago.

-Alan



NetFixer
Freedom is NOT Free
Premium
join:2004-06-24
The Boro
Reviews:
·Cingular Wireless
·Comcast Business..
·Vonage

Glad to hear that you have tentatively found a solution.

I almost mentioned the possibility of buffer bloat, but I backed off because so many people don't believe that it exists (and I have to be careful in this forum about making controversial posts) . I have experienced some buffer bloat symptoms on my network, but not as severe as yours. On my network, the primary symptom I would see was poor quality VoIP.

One on-line test that can be run to check for buffer bloat (among many other things) is Netalyzr. Warning! This test requires Java, so anyone who doesn't want to run a Java app over the Internet should not bother to click the link.

Here is the buffer bloat test segment result when I have minimal upstream rate limiting enabled:

said by Netalyzr :

Network buffer measurements (?): Uplink 360 ms, Downlink is good –
We estimate your uplink as having 360 ms of buffering. This level may serve well for maximizing speed while minimizing the impact of large transfers on other traffic.
We were not able to produce enough traffic to load the downlink buffer, or the downlink buffer is particularly small. You probably have excellent behavior when downloading files and attempting to do other tasks.

This is what I see from the same test if I disable upstream traffic shaping:
said by Netalyzr :

Network buffer measurements (?): Uplink 710 ms, Downlink is good –
We estimate your uplink as having 710 ms of buffering. This level can in some situations prove somewhat high, and you may experience degraded performance when performing interactive tasks such as web-surfing while simultaneously conducting large uploads. Real-time applications, such as games or audio chat, may also work poorly when conducting large uploads at the same time.
We were not able to produce enough traffic to load the downlink buffer, or the downlink buffer is particularly small. You probably have excellent behavior when downloading files and attempting to do other tasks.

Depending on network conditions, sometimes the upstream buffering for my connection is over a second.

I didn't bother to do it for this post, but if I use an old DOCSIS 2 modem (no channel bonding), the upstream buffering drops to ~60 ms.
--
A well-regulated militia, being necessary to the security of a free State, the right of the people to keep and bear arms shall not be infringed.

When governments fear people, there is liberty. When the people fear the government, there is tyranny.


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

How are you certain that it is the modem and not something farther upstream ?


FirebirdTN

join:2012-12-13
Brighton, TN
kudos:1
Reviews:
·Comcast

1 edit

Hmmm, by upstream I do not know if you mean further along the comcast network, or further along my home network?

But to try and answer:

Prior to implementing upload traffic shaping on my router, I ran some packet loss testing internally from my LAN headed toward the internet, and from the internet headed toward my LAN [tested from my office PC at work on a 20/20 fibre connection].

When total network failure occurred, internally I could get all the way from my PC to the modem itself, but no further. From the internet I could get all the way to my first hop, but no further. This isn't quite conclusive, as I don't have the ability to test to the modem *itself*, but...its the best I can do. [It will be interesting to hear the Comcast tech's results after monitoring my connection-I'll lay money down he did not see any drops at all. Unfortunately, I haven't heard from him since Thursday].

So, logically that would indicate an issue between the modem itself and the first hop. Cabling, signal levels, etc have all been eliminated as a source of the trouble. That only really leaves the modem itself.

When I swapped out for a D2 emta, the *packet loss* went away completely [but the high latency under load did not]. When I swapped out for a newer D3 emta than the one I originally had, the problem returned, but this time with even *longer* periods of total packet loss.

Now at this point, you *could* say its just a staggering coincidence and I actually had two defective D3 modems, BUT...to have two separate devices fail in the exact same manner would be extremely rare.

But I think the final nail in the coffin was after implementing traffic shaping [on the upload path only, the download path is set for full speed], not only did the loss disappear, but the accompanying high latency during my wife's iPad usage that always precipitated the 100% packet loss did as well, and that is while testing under the exact same load conditions prior to implementing the traffic shaping.

I ran pingplotter for over six hours last night under high load, and had not one single lost packet, and the highest latency to the first hop the entire time was 76ms.

-Alan


switchman

join:1999-11-06

1 edit
reply to FirebirdTN

Good to hear you think it is solved. I recently, within the last month, implemented QoS rules on my router. I can see the difference in my network. With multiple devices using the network I could experience slow downs/pauses in normal browsing. In my case, I could look at the link and see that I was saturating it so knew I needed QoS to solve my issue. After the QoS rules were put in place, no more issues. This goes to show that with properly implements QoS at the endpoint, possibly a lot of problems people have or appear to have with there internet provider could be solved. I am surprised that the service providers do not push a QoS profile down to the modem/routers they provide. But maybe some of them do. Obviously this would not help where the customer is only using it as a modem as you are.

Not to hijack your thread, but for anyone using Tomato and interested in QoS, Toastman has developed a very good set of rules that seem to work well. I am using his rules on a Shibby build. More information can be found here.

»tomatousb.org/tut:using-tomato-s-qos-system
and here
»tomatousb.org/tut:easy-toastman-qos-setup

After setting up these rules, I tweaked the the rates and tested it on a 30/5 link. During the testing I can download a file at ~20Mb/s, stream two Netflix streams in HD quality and do normal web browsing with no slowdown in performance.



workablob

join:2004-06-09
Houston, TX
kudos:3
Reviews:
·Comcast
reply to FirebirdTN

I too have been having this issue. I'll be surfing and the modem will reset.

It sometimes happens several times a day.

It's been happening for about the last month or so.

Dave
--
I may have been born yesterday. But it wasn't at night.


FirebirdTN

join:2012-12-13
Brighton, TN
kudos:1
Reviews:
·Comcast

workablob-

I think you might have a different issue. In my case, my modem NEVER reset. Signal levels never waivered. And modem indicators never changed. As far as looking as all aspects of the modem, it was all well and perfectly happy, even during my service disruptions. Its a shot in the dark based on very limited info, but if your modem is resetting under load, it may just be going bad.

Since I'm posting back in here, I can happily report I was problem free ALLLLLLL WEEEKKKEND LOOOONGGGG whooHOO!!!!

-Alan



workablob

join:2004-06-09
Houston, TX
kudos:3
Reviews:
·Comcast

said by FirebirdTN:

workablob-

I think you might have a different issue. In my case, my modem NEVER reset. Signal levels never waivered. And modem indicators never changed. As far as looking as all aspects of the modem, it was all well and perfectly happy, even during my service disruptions. Its a shot in the dark based on very limited info, but if your modem is resetting under load, it may just be going bad.

Since I'm posting back in here, I can happily report I was problem free ALLLLLLL WEEEKKKEND LOOOONGGGG whooHOO!!!!

-Alan

I see.

I started the Netalyzer tool and it almost finished but now the netalyzer site is down.

»www.downforeveryoneorjustme.com/···u/,d.aWM

Dave
--
I may have been born yesterday. But it wasn't at night.