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Jon Jon

@comcast.net
reply to koitsu

Re: What to do about 11 weeks of node/network problems?

downloadpathping.txt 2,864 bytesdownloadtracert.txt 1,949 bytes
Well, I see I am NOT alone when it comes to Comcast and their rediculously poor customer support. Maybe we should form our own club?
I too have been losing information packets for the last 2 weeks, and all the phone techs can do is reboot my (brand-new) Modem. So, I went further, and here is what I did.
I ran a 'tracert' and a 'pathping' to the server I am trying to connect to (as the phone tech didn't know what to do), and saved them as .txt so I can e-mail/send. It is evident that on my 2nd and 4th hop I am losing 100% sent/recieved packets, and my HSI is dropping and/or super slow with extremely high latency. I brought this up to the phone tech, and they scheduled me a 'tech' visit for Friday the 2nd 3pm. He came and went like there's no tomorrow! The only thing I got out of him is that from the telephone pole to my house connection, my upstream @ the tap is 48.75, which is, obviously, 'extremely high'. He couldn't do anything else, said he would tell 'maintenance', and left.
I called this morning to see where I stood with Comcast, and guess what? They had 0 knowledge about the tech, and that he notified maintenance, and she wanted to 'reset' my Modem (again). I stopped her dead in her tracks, asked for a supervisor, as it's obvious she didn't know crap, and she 'refused' to get me a supervisor. (???) I told her to give my # to any supervisor so they can call me, and as of date, 0 phone call.
I currently attend college, and I need my internet for reference, contact with school, etc.
Someone tell me...where do I go from here???
Verizon???


koitsu
Premium,MVM
join:2002-07-16
Mountain View, CA
kudos:23

1 recommendation

I want to be very clear here with my words:

I do not want this thread to become a "me too" or "f*** Comcast!" thread. I see too many of those and they do absolutely no good.

Every person's situation is different. I sympathise that you've been dealing with "high pings" for 2 weeks (although the evidence you've presented is only 50% applicable; your "pathping" shows high latency when talking to the CMTS, but your "tracert" doesn't), but that's a very different situation and handled in a very different way (and at a different layer) than what my issue is. Mine relates to actual cellular tower interference making it into a cable node, affecting a large number of people (I don't have actual statistics but I can confirm my neighbour who has the same setup I do sees the same problem), while yours relates to what could be your own connection being saturated or a CMTS capacity issue. Comcast can help diagnose your situation much easier than mine, and there are employees on this forum who can help. In my case, the only people who can resolve the issue are network/line techs, and I have no escalation path for those.

I recommend rather than "hijacking" (I use the term lightly) this thread for your problem, you start your own. What I requested in this thread is for feedback/advice from people on where to go from here with regards to my situation. Again: each situation must be handled individually.
--
Making life hard for others since 1977.
I speak for myself and not my employer/affiliates of my employer.



MemphisPCGuy
Taking Care Business
Premium
join:2004-05-09
Memphis, TN

Have you tried posting in the Comcast Direct Forum to see if ComcastSteve can kick it up and over for you?
--
Onsite Computer Support in Memphis
»www.memphispcguy.com



HeadendJoe

@comcast.net
reply to koitsu

You can try writing the FCC and reporting the issue. Also, at the bottom of your bill states who your local franchise authority is. Contact them regularly about the problem and they'll pressure comcast to work on a fix. Also, if you know of a business customer on that node that can complain, it will become a higher priority.

When you say the tech was able to reproduce the problem at the headend, do you know what methods he used to do that or what exactly was reproduced?



Streetlight

join:2005-11-07
Colorado Springs, CO
reply to MemphisPCGuy

said by MemphisPCGuy:

Have you tried posting in the Comcast Direct Forum to see if ComcastSteve can kick it up and over for you?

The OP wrote, "I have posted about this issue in the past on the Comcast Direct forum and it was read a couple times but never solicited a reply from ComcastSteve See Profile or anyone else."


koitsu
Premium,MVM
join:2002-07-16
Mountain View, CA
kudos:23

Click for full size
said by Streetlight:

said by MemphisPCGuy:

Have you tried posting in the Comcast Direct Forum to see if ComcastSteve can kick it up and over for you?

The OP wrote, "I have posted about this issue in the past on the Comcast Direct forum and it was read a couple times but never solicited a reply from ComcastSteve See Profile or anyone else."

To be more specific I've included a screenshot. Like I said, no response, but 2 people have looked at it. In that ComcastDirect post thread I did provide the official Comcast Forums post/thread.
--
Making life hard for others since 1977.
I speak for myself and not my employer/affiliates of my employer.


koitsu
Premium,MVM
join:2002-07-16
Mountain View, CA
kudos:23
reply to HeadendJoe

said by HeadendJoe :

You can try writing the FCC and reporting the issue. Also, at the bottom of your bill states who your local franchise authority is. Contact them regularly about the problem and they'll pressure comcast to work on a fix. Also, if you know of a business customer on that node that can complain, it will become a higher priority.

My bills are digital/paperless; let's see what the billing statement PDFs have in them...

quote:
Your Local Franchise Authority Is:
City Of Mountain View
500 Castro St P.o. Box 7540
Mountain View, CA 94039
Ph:(650) 903-6301, FCC Unit #CA0906
(THIS IS NOT A PAYMENT OR SERVICE CENTER)
How convenient -- that's about 3 blocks from where I live.

I do not know of anyone with business-class service around here. I only know my immediate neighbours in my 6-apartment unit; most of the folks have DOCSIS 1.1 and 2.0 modems so they don't have channel bonding, and their modems aren't actively using frequencies at or above 747MHz (I've looked -- really! A little odd to ask neighbours if I can use their PC for a moment, but true story). Two of the neighbours don't use Comcast at all, so my demographic is limited.

Regarding the local franchise authority: what exactly do I tell them? I've never done something like this before.

said by HeadendJoe :

When you say the tech was able to reproduce the problem at the headend, do you know what methods he used to do that or what exactly was reproduced?

I don't know what methods were used, only that "in the field" he claims he could not reproduce the problem. The problem is abysmally bad SNR (29-32dB) starting at 747MHz or thereabouts, and it gets worse as the frequency increases (so 753MHz is really bad).

Taken directly from my notes with names and numbers XXX'd out for obvious reasons. XXX in this case is the line tech.

said by koitsu:
09/18 – Afternoon (3:50pm) – Call from XXX. Stated that he took readings at the head-end and confirmed the fluctuations in SNR/noise for 747/753MHz, indicating that the issue is “at the node”. XXX said he’ll be working tomorrow with a head-end engineer to try and track things down further, but that they didn’t have time today because there was only one head-end engineer available due to a major issue/problem which happened last night + kept them awake for long hours. XXX said he’ll call me tomorrow with details of what transpires/ask for verification of improvement/etc. I told XXX in the meantime I’d be rebooting my cable modem to try and dismiss use of 753MHz for the time being; he said that’s fine. Also took down XXX’s number per Caller ID: 650-XXX-XXXX

...

09/21 – Morning – Call from XXX. After discussing it with many of his colleagues, apparently a couple of them had seen this exact situation happen before up in San Carlos (specifically 747/753MHz). The root cause turned out to be interference injected into a node by a nearby AT&T cellular tower. As it turned out there was a faulty cable they replaced (visual inspection of the cable showed no problems but the cable was 20+ years old) to resolve the issue.

So at present they’re fairly certain this is what’s causing the problem here in Mountain View, but need to put in the hours/time to try and figure out where the noise is being injected and inspect and/or replace cables. XXX also noted that he had an on-site injury 2 days ago (damaged his knee and hip) but he has another tech working with him directly to get this issue fixed. The downside is that it may take some time (few weeks, maybe longer). I told XXX that is completely 100% acceptable, and that I considered all of this good news not bad.

So for now, my plan is to stick with using frequencies other than 747/753 (may take repeated reboots of my modem), since I have a working connection in that situation. I asked XXX give me periodic updates (weekly or bi-weekly if need be) to let me know how things progress, and that if they need anything from me to give me a call. He assured me he’d do just that.

09/21 – Morning – Wanted to called XXX back to let him know that based on some Internet resources, the issue may be with Verizon 4G/LTE and not AT&T:

»www.wpsantennas.com/cellular-fre···ion.aspx

However, 650-XXX-XXXX required either knowing the individual’s last name or their extension, of which I know neither. I’ll tell him of this the next time he calls me.
You can see the SNR for yourself here (Firefox, Chrome, IE9, or IE10 required -- nothing I can do about that, sorry):

»jdc.koitsu.org/snrgraph/

I can make the data for all of August available if need be; just ask.

You can see that there's no issue at present only because I've rebooted my modem a bazillion times to get it to pick frequencies other than 747 and 753MHz. But you can see at least on October 9th the issue was still there.
--
Making life hard for others since 1977.
I speak for myself and not my employer/affiliates of my employer.


HeadendJoe

@comcast.net

Regarding contacting your franchise authority, you're best bet is to call them and explain the situation. From there they'll let you know what steps they will take to help resolve the problem.

So, I'm not sure if I'm reading your notes correctly but it sounds like the tech called in to the headend about those last two QAMs. I'm guessing that the headend threw the analyzer on there and saw no problems on their end which is why the tech stated the issue was at the node. If he's seeing the problem at the testpoint of the node, then there is an issue with the RF at the physical node. If he doesn't see the problem there, but at your end, then he's got to go down the line until he finds the problem. It would be unusual if the problem wasn't found after all this time. There's a lot of posibilites so its really hard to say. Worst case, call them again and tell them to roll a truck out to you. The guys in the truck will know more than anyone you speak to on the phone. Hell, ask the guy that shows up for his shop manager's email address and contact info, then you'll be able to have documented correspondence with someone that has the authority to finally fix the issue.



koitsu
Premium,MVM
join:2002-07-16
Mountain View, CA
kudos:23

Some clarification about my notes:

1. By "line tech" I am referring to an actual network line tech (the guys who drive around with bucket trucks and fix problems), not a service technician (the guys who come to your house and check everything between the cable modem all the way up to where the cable comes in off the pole).

2. Line tech was not able to see the issue in the field (was unable to see bad SNR for 747MHz or higher). I wasn't give any details other than that; just that "in the field" he couldn't see the problem. He stated that he was going to go to the head-end later that day and see if he could see it from there.

3. The follow-up call I got consisted of him saying the following, which didn't make any sense to me (this is why I put "at the node" in quotes): "I went to the head-end and yeah I can see the problem there at the node". I said "the node? Did you mean the head-end?" and he said "no, at the node".

As I understand it, "the node" refers to the cable node/segment (which correlates with a small or large geographic area, i.e. a "segment" of the cable network from which customers get their drops) while "head-end" means where (or near where) the CMTS is. So this is why I put "at the node" in quotes because I'm not sure what exactly he meant by what he said, given the terminology I've learned. I often get the impression all these techs (service and line/network) "re-use" terms to describe multiple things.

4. Line tech stated that after chatting with fellow techs about this problem, one reminded him of this issue happening in San Carlos (about 15 miles from here) but he himself had forgotten about it. He then told me the story about having to replace a long run of cable up there which looked fine but obviously was taking noise. I asked how they managed to figure out it was that cable. He said there's a device they have which allows them to look for leakage, but it's a long and drawn out task because it requires 2 people and a lot of walking.

Now for a question:

Doesn't a "truck roll" refer to sending out a line/network tech? If so, from whom do I ask this? Comcast? I have talked to Comcast CSRs (800-COMCAST) more times than I can count, and have requested line/network techs twice already -- what they send is a standard service tech every single time, who goes "yeah you have your ducks in a row, sounds like a network problem, not much I can do, you should talk to that network/line tech you've met". (Yeah that's nice, I would if I had his surname/extension...)

Or is this something I'm supposed to ask my LFA?
--
Making life hard for others since 1977.
I speak for myself and not my employer/affiliates of my employer.


JoelC707
Premium
join:2002-07-09
Lanett, AL
kudos:5

said by koitsu:

As I understand it, "the node" refers to the cable node/segment (which correlates with a small or large geographic area, i.e. a "segment" of the cable network from which customers get their drops) while "head-end" means where (or near where) the CMTS is. So this is why I put "at the node" in quotes because I'm not sure what exactly he meant by what he said, given the terminology I've learned. I often get the impression all these techs (service and line/network) "re-use" terms to describe multiple things.

The node is a glorified media converter essentially. It takes the optical feed from the hubsite and converts it to the coax running around neighborhoods. The CMTS generally exists at the hubsite level not the headend level. Some might reuse headend to mean hubsite but with everyone having their own ways of saying things it's really anyone's guess.

Think of the headend as the main aggregation point for a geographic area. It feeds many different hubsites that themselves feed many different nodes. There may be more than one headend for an area depending on size, Atlanta has two that I know of: Stone Mountain and Vinings but I believe there are two others that probably came from other cable system acquisitions and general expansion.

said by koitsu:

4. Line tech stated that after chatting with fellow techs about this problem, one reminded him of this issue happening in San Carlos (about 15 miles from here) but he himself had forgotten about it. He then told me the story about having to replace a long run of cable up there which looked fine but obviously was taking noise. I asked how they managed to figure out it was that cable. He said there's a device they have which allows them to look for leakage, but it's a long and drawn out task because it requires 2 people and a lot of walking.

That is a cable leak detector and there can be vehicle and hand-held versions. Looks like they have really changed since the last one I had my hands on. The one I had really resembled a radar gun and had two telescoping antennas coming out each side. It could require two people but sometimes will be done with one depending on what they are looking for.

If they are looking for signal egress (signal leaking out) that can be done with one person driving around until he/she gets to the general area and then going on foot. If they are looking for signal ingress (signal making it's way in), that really does require two people. One to sit at your house and/or designated test points with a sensor and the other to drive around broadcasting a specific signal that sensor will be looking for.

Suffice it to say, depending on the area this issue could be fixed either from you pushing them or the FCC/FAA pushing them. If you live near a major airport or are in a major flight path, the FAA will do flyovers and identify hot spots that need attention. As such, your area may get flagged and fixed eventually even if you don't push them (not that I'm saying you shouldn't try, just that it may one day "fix itself" so to speak).


HeadendJoe

@comcast.net
reply to koitsu

He could have had the headend techs check the transmitter for your node. They could then see whether or not those last two QAMs had MER/BER issues or if the signal from the NSG was degraded on those last two QAMs. If he truly saw the problem at the headend for your node, then that means those last two QAMs are degraded at the NSG because of a faulty card. A simple card swap at the headend and it's fixed. However, I doubt that's the problem or else it would have been fixed already. So, honestly I'm not sure what he meant there.

What you call "line tech" is what Comcast calls "Maintenance Techs". Maintenance techs do have the ability to walk the line with sniffer guns to locate where interference is entering the plant or where signal is leaking. I don't know how CSRs dispatch calls these days, but next time you call in, specifically request that you want a maintenance tech or a CommTech 5 tech to come diagnose an issue with the plant.

Also still contact the LFA and report the problem. Municipalities love fining cable companies for not being in compliance with maintaining their plant. Fines tend to jump start maintenance efforts.



EG
The wings of love
Premium
join:2006-11-18
Union, NJ
kudos:10

said by HeadendJoe :

I don't know how CSRs dispatch calls these days, but next time you call in, specifically request that you want a maintenance tech or a CommTech 5 tech to come diagnose an issue with the plant.

Isn't it basically their S.O.P. that the phone reps can not do this and that only the premise facing techs can escalate an issue to the maintenance / network dept.


koitsu
Premium,MVM
join:2002-07-16
Mountain View, CA
kudos:23

said by EG:

said by HeadendJoe :

I don't know how CSRs dispatch calls these days, but next time you call in, specifically request that you want a maintenance tech or a CommTech 5 tech to come diagnose an issue with the plant.

Isn't it basically their S.O.P. that the phone reps can not do this and that only the premise facing techs can escalate an issue to the maintenance / network dept.

This is correct. The CSRs will open up a new CR (ticket/case) and will only schedule a standard service technician to come out. That technician and his supervisor are the ones who make the decision to "escalate the problem to network" (as in make a case and hand it off to network/line techs (maintenance techs) to deal with), and that's quite literally the last the customer ever hears of things (i.e. the assumption is made by all involved that network/line will resolve the issue). I speak from experience on this one. :-(

In my case, I was able to meet the network/line tech (maintenance tech) solely because of a Comcast employee on the official Comcast Forums (who shall remain anonymous per their request) "putting in a good word" for me behind-the-scenes + reaching out to someone at my local repair office (in Menlo Park) to look at the case. It was total chance that I actually *met* the guy -- I happened to be looking out my window the next day and saw a Comcast truck (with bucket) outside, where the driver got out and wandered around near our property looking up at utility poles. I went out and talked to him, asked him if he was handling my CR #, and he was. That's the guy, by the way, who I mentioned above (re: went to head-end, reproduced issue with 747MHz and higher, determined issue was same as what was seen in San Carlos).

If I call 800-COMCAST, all the CSRs are going to do is open up a new CR/case, link it/tie it to the old ones, and schedule to have a service technician come out. I've been down this road 3 times already, and all it does is waste service technicians' time since they can't solve the problem.
--
Making life hard for others since 1977.
I speak for myself and not my employer/affiliates of my employer.


koitsu
Premium,MVM
join:2002-07-16
Mountain View, CA
kudos:23
reply to HeadendJoe

Thanks, HeadendJoe, and JoelC707 See Profile (hi dude ).

As surprising as it might sound, I actually understand most of the terminology you've used, sans two terms: MER and NSG. I know what QAMs are, and I know what BER is (bit error rate; from my experience with DS1/DS3/OC3/OC12 and SONET), but the other two are new to me.

I put in a call to the "general manager" who I'd spoke to in the past (about service technicians). I think I'm going to let things sit until Wednesday.

If I don't get a call back from him by then, I'm going to try an alternate approach -- I do have a contact at Comcast who handles the PR and IP networking side of things, and I have a good relationship with that person. Possibly they can get me in touch with someone who can drive this.

Otherwise if that goes no where, I'll give my LFA a call and approach it from that angle.

I guess on the positive side, there's lots of hard data/evidence that I can provide, and there is a part of me (the engineer part ) that's happy that Comcast was able to confirm existence of the issue. Sometimes tracking down a problem is the hardest part. In this case though it seems to be getting it fixed that's a pain.

Will let folks know what transpires.
--
Making life hard for others since 1977.
I speak for myself and not my employer/affiliates of my employer.



HeadendJoe

@comcast.net

This is a NSG »harmonicinc.com/product/nsg-9000-6g

Essentially its an edgeQam that receives optical info and generates the info into RF QAM channels. So how Comcast works is that their CMTS routers are uBR10012 Cisco routers. The Downstream info (signal from the headend device to the node) leaves the router via fiber to the Harmonic NSG. The NSG outputs the info into multiple RF QAMs. Those QAMs eventually reach a transmitter where its converted back to optical, sent to the node, and then converted back to RF. Comcast also uses NSGs to convert VOD optical streams to RF QAMs.

Just a few definitions for you. MER (Modulation Error Rate) is the digital equivalent to SNR, which is the baseband measurement equivalent to Carrier to Noise. MER measures the ratio of error power to average power in an ideal QAM signal. MER measures the difference in quality between the transmitted modulation of a digital signal and the received modulation. Carrier to noise ratio is the measurement of the distance between a modulated RF carrier and the inherent noise floor. You can find a little more detail about these on Wikipedia.

Keep us updated for sure, hopefully it will get fixed. If you end up calling the FCC or your LFA, make sure you ask about Comcast's POP (proof of performance) testing. I believe by law the public has the right to review the outcome of those tests. They do the tests twice a year. May be worth glancing over if you're interested in where they found leaks in the plant during the test.