Basic Internet Connectivity And Modem Help

[INTOXSICKATED]

I have the 50mbTriple Play download package.  I'm not sure what it's called, but that's the one I've got.  When things are running good, I get 60+mb on my download and 12mb or so on the upload.  The problem is, it fluctuates big time!  I just tried to play MW3 on Xbox Live and the lag was excrutiating.  I realize trhat there's other factors involved, but when nobody else is having the problems I'm having, something's nto right.  I decided to run some tests and I had a 2mb download, and the jitter and ping test at pingtest.net couldn't even finish.  Eventually it did and my ping was like 900 and the jitter was like 10,000.  Of course I reset everything and that helped for a bit, but then the same thing came back again.  This is nothing new, I've been dealing with this for a couple of years.  I started a thread a while back on this forum talking about the same problem.

Just yesterday I swapped out my modem because it stopped communicating.  No sign of it going bad on Comcast's side, it just died all of the sudden.  The phone worked, but I had no internet and Comcast tech support told me to bring it in.  Now I have internet, (sometimes), but my phone won't work.

A tech is coming out Saturday morning to look into things.  The problem is, I've had tech's out here probably 5 times now.  Nobody can ever find any problems.  My situation is not all the time and is sporadic, so it's hard to diagnose and I understand that.  

Usually Comcast says everything looks good on their end, but now they can see that something is going on because I have no phone service.

I've done EVERYTHING that I can do to try and fix this.  The wires inside and the line from the outside to the inside has been replaced.  The router's been replaced more than once, right now I'm using the Comcast SMC gateway.  I've changed ethernet cables many times, splitters, phones, phone cords, computers...nothing helps.

So here's my question.  There's a good chance that the Comcast tech will come out Saturday and everything will be fine and he'll tell me I'm all good and go away.  What can I ask him to check, what can I have him do to try and find some kind of problem here?  What else could it be?

By the way, my TV works great, no cable problems there.

I'm at my wits' end with all of this and finally started looking into getting U-verse instead.  The $25 credit I just received isn't worth my frustration.  I have no problem paying for faster speeds because that's what I want and U-verse doesn't provide that, but a stable connection is better than one that works only when it wants to.

I posted my modem specs below.

HW Version:Vendor:BOOT Version:Core Version:Modelroduct Type:Flash Partownload Version:Serial Num:

1C

SMC Networks

PSPU-Boot(BBU) 1.0.9.15-H2.6

2.1.3.5.6.1

SMCD3GNV

SMCD3GNV

32 MB

2.1.3.5.6.1

H21040065DA7

Downstream Channel Bonding ValueIndexLock StatusFrequencySNRPowerModulation

1	2	3	4
Locked	Locked	Locked	Locked
705.002 MHz	710.999 MHz	717.000 MHz	723.001 MHz
35.973 dB	36.175 dB	35.973 dB	36.175 dB
-0.682 dBmV	-0.238 dBmV	-0.427 dBmV	-1.485 dBmV
256 QAM	256 QAM	256 QAM	256 QAM

Upstream Channel Bonding ValueIndexLock StatusFrequencySymbol RatePower LevelModulationChannel ID

1	2	3	4
Locked	Not locked	Not locked	Locked
30599564 Hz			25300000 Hz
5120 KSym/sec			2560 KSym/sec
32.7500 dBmV			32.7500 dBmV
64QAM			16QAM
7

[INTOXSICKATED]

DiffProbe release. January 2012. Build 1008.
Shaper Detection Module.

Connected to server 74.63.50.40.

Estimating capacity:
Upstream: 132 Kbps.
Downstream: 13482 Kbps.

The measurement will take upto 5.0 minutes. Please wait.

Checking for traffic shapers:

Upstream: Burst size: 136 KB;
Shaping rate: 74 Kbps.

Downstream: Burst size: 22336-22606 KB;
Shaping rate: 6906 Kbps.

For more information, visit: http://www.cc.gatech.edu/~partha/diffprobe

[oMellow]

Extreme 50 shoudlnt have burst speeds and it should have an upload of around 15000kb and a download of about 50-60000kb. From my experience you probably have the wrong config file. I too am having problems with my speeds. I never even get 50-60mbps and i stay around 35. Questioning whether I should stay with comcast or not...

[INTOXSICKATED]

Are you hardwired or wireless when testing speeds?  If wireless, 35 is good.  Wireless I get around 20 or so.  It's only when I'm hardwired directly to the modem that I get 50-60mb dowload speeds.  

[oMellow]

I get 35 hardwired and wireless. Do you have gigabit ethernet or 100mb? Maybe that is my problem

[INTOXSICKATED]

Mine's a gigabit.  Not sure if that's your problem though.

[jasleinstein]

I had 50 Mbps service for a while. At first I had lots of intermittent issues. It was very frustrationg , but I stuck with it and worked with the field techs. I found them to be good people. A bit under trained and poor people have no tools to work with. At first we had the Comcast vs customer trust issue, until I answered the door with my cisco shirt on. then we established trust. I borrowed a network monitor/sniffer from a local integrator and had a real network tech look at it for me. We established a trust and the techs gave me thier cell phone numbers and internal ip addresses for the head end switch and DNA servers. As it turned out every time they were in the neighbor. Hood balancing amplifiers for other houses it screwed up my connection. After a couple of months they got the network tuned and life was wonderful. For months I had consistent 35 to 60 MBA service. The way Comcast networks are designed it is going to be a very problematic future. Comcast neighborhood networks are akin to networks built inthe 1980 with shared bandwidth. Every house on your drop shares the bandwidth. Today the max is 200 Mbps. I am lucky as our drop only has a couple hundred houses on it, many have as high as 300. It's like a water facet in your back yard. With one hose connected you get great flow, with two hoses connected you get say %70, three maybe %40 etc. BTW I dropped the service for lower speeds and now i can't stand it. I might go back. If you have technical skills and can afford to work with the techs try to do so. They have so few tools to work with it is hard for them. If you want good network reliability you have to pitch in, Comcast corporate is happy to have its customers do its job for them.

[INTOXSICKATED]

I feel like I've already done my part to help Comcast diagnose a problem here.  I also understand how their network works, (to a certain degree).  That's why I'm looking into the U-verse thing now.  Even though it's slower, maybe a dedicated line would be better than what I already have.  Last night it took me 10 minutes to download a 768kb file, I think my 56k was faster back in the day.

I am in an apartment complex, but there are only 6 units in my complex.  One of the Comcast techs told me that 3 of them are using Comcast, but I don't know how many people are on  my actual drop.  

I have a feeling that something from a neighbor is causing interference on my line, but I don't know how to go about fixing that or diagnosing it.  Never used a network sniffer before.  Right now my connection seems to be great as well, althoguh I still have no home phone.

I'm going to wait and see what happens Saturday I guess, then I'll probably just have to drop them as I'm sure nothing is going to come of this next visit.  

[EG]

---

jasleinstein wrote:
Today the max is 200 Mbps.

---

FWIW, this is an *absolute* statement. Every local system / market area is different. Any area that has eight bonded downstream carriers has a capacity of around 300 Mbps down.

[jasleinstein]

EG, Do the math. Any number divided by 300 homes passed ,,, sucks. There is over subscription then there is Comcast over subscription. For most links that have well over 300 homes connected I am told by the Comcast techs 350 to 400 is common. What if just 10 homes of the 300 bought the 40 mbs/sec service ( 10 x 40 = 400mbs and these are best case lab numbers, real world deployment would cut these numbers by at least%20) In the investment world I think this is called a ponzi scheme.

[INTOXSICKATED]

The Comcast tech came out and accomplished nothing.  Of course at 9:00 in the morning, the internet was screaming fast.  He did get my phone going, but he didn't understand why it couldn't be done by tech support over the phone in the first place.

At night between 5 and 10pm, my internet speeds slow to a crawl.  Sometimes it's not too bad, but sometimes, I can't even get a website to load.  Regardless, gaming is totally out of the question.  When I run speed tests during these times, they either won't complete, hang, or show me numbers that are way off.

I'm convinced that either my node is over subscribed or I'm getting interferrence from a neighbor or something.  I just don't know.  For now though, as long as I stay off the net at night, I am a happy camper. 

[jasleinstein]

do you know your neighbors? if you can find others that use online get thier number and call each other when you have issues. then relay that info to the comcast techs. the company is to cheap to give them network tools so they have to brute force fixes. i am sure the tech would use the info you give them . Maybe set up tech visits in the evening. If you know any Juniper, Cisco, H-P, Microsoft techs as if they could run over and bring a network sniffer. i used to have good performance but as of the last few weeks noticing delays in the evenings. even notice more and more pixelaztion on the HD systems for TV in the house. in talking to neighbors they are seeing the same. Rut row, i fear trouble scubby doo., we live in an old section of Seattle so our cable runs downthe alley. i know which direction the cable head end is. maybe i'll go out cut the downstream side of our cable. Just kidding. BTW are you using the comcast speed test? If you use an external test like speakeasy you cant get a good read as you cant tell if the problem is in the Comcast network, or on the other side, i.e. the link between comcast and Speakeasy, or who ever you use. if you can look up your DNS server numbers, during the times of bad performance ping those DNS servers, then during good times ping them again. Look at the turn around times for the pings. If there is a local problem, there is a good chance ping return times will show a difference. I was able to get the IP addresses of the head end switch from my local techs, but i know for a fact that is frowned on. Last week we had a DNS outage and I used that info with support tech. She very nicely completely ignored me. if you don't know how to use ping just google it. good luck.

[Jim721]

Wow Good advice but after all that I would want a paycheck from Comcast.

[EG]

Nevermind. Not even worth it....

[INTOXSICKATED]

I'm kind of done with trying to troubleshoot my problems.  I work 50 hours a week as it is, I don't need to come home and do someone else's job too.  I'm currently looking at alternatives to Comcast in my area, but there isn't much else available.  

I might go bug the neighbors out of curiosity tomorrow to find out if they're having problems as well, but most of them are old and probably wouldn't even notice if there was something up in the first place.  I could be wrong though.

All I know is.....I'd rather be kicked square in the nuts than have to call Comcast tech support or see another one of their techs in person again.  Not that they aren't nice people, it's just that they are borderline retarded and I'd get more satisfaction from talking to a rubber chicken.

[dsanbo]

Intox......

Please.....Tell us how you REALLY feel.......

[virtuallynathan]

I beleive you said you tried another modem - which kind?

[INTOXSICKATED]

I've had five, maybe six modems.  The last one I had was an Arris, the one I have now is the SMC gateway all-in-one router / modem thingy.  Before that I had the Ubee.  

I don't remember the one's I've had before then, nor do I know their model numbers, but I've had this SMC gateway before and I've had other Arris modems as well.  

Do other people have this much bad luck with modems?  Is it common to replace them every few months?  You think Comcast would be able to look at their records and see how many modems I've gone through and how many times they've been to my house.  You think it would send a red flag on their end or something saying that there's obviously something wrong here.

Tonight I decided to play some games, and much to my surprise, my connection is great.  I ran some tests and verified that at the moment it's all running superb.  

By the way, sorry for rude post yesterday, I shouldn't be drinking rum and surfing the web. 

[Jim721]

Nevermind. Not even worth it....

  You say that alot what does it mean ??

[INTOXSICKATED]

I have lost almost all connection to the internet again after it was running well for the past few weeks.  Well, nto well, but tolerable.  Now Cocmcast is saying that yet again my modem has gone bad.  They are sending a tech out on Thursday to check things over.....AGAIN!

I noticed these errors on the modem, anyone know what they mean?

Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=00:26:f3:6d:a9:80;CMTS-MAC=00:01:5c:31:fd:57;CM-QOS=1.1;CM-VER=3.0;	2012/07/03 18:32:33	critical
Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:26:f3:6d:a9:80;CMTS-MAC=00:01:5c:31:fd:57;CM-QOS=1.1;CM-VER=3.0;	2012/07/03 18:11:03	critical
Initializing Channel Timeout Expires - Time the CM can perform initial ranging on all upstream channels in the TCS has expired;CM-MAC=00:26:f3:6d:a9:80;CMTS-MAC=00:01:5c:31:fd:57;CM-QOS=1.1;CM-VER=3.0;	2012/07/03 18:10:42	warning
TCS Partial Service;CM-MAC=00:26:f3:6d:a9:80;CMTS-MAC=00:01:5c:31:fd:57;CM-QOS=1.1;CM-VER=3.0;	2012/07/03 18:10:42	warning
No Ranging Response received - T3 time-out;CM-MAC=00:26:f3:6d:a9:80;CMTS-MAC=00:01:5c:31:fd:57;CM-QOS=1.1;CM-VER=3.0;	2012/07/03 18:10:35	critical
Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=00:26:f3:6d:a9:80;CMTS-MAC=00:01:5c:31:fd:57;CM-QOS=1.1;CM-VER=3.0;	2012/07/03 18:08:16	critical
Service Delete rejected - Service flow not found;CM-MAC=00:26:f3:6d:a9:80;CMTS-MAC=00:01:5c:31:fd:57;CM-QOS=1.1;CM-VER=3.0;	2012/07/03 18:03:18	error
Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=00:26:f3:6d:a9:80;CMTS-MAC=00:01:5c:31:fd:57;CM-QOS=1.1;CM-VER=3.0;	2012/07/03 18:03:16	critical
Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:26:f3:6d:a9:80;CMTS-MAC=00:01:5c:31:fd:57;CM-QOS=1.1;CM-VER=3.0;	2012/07/03 17:53:46	critical
TCS Partial Service;CM-MAC=00:26:f3:6d:a9:80;CMTS-MAC=00:01:5c:31:fd:57;CM-QOS=1.1;CM-VER=3.0;	2012/07/03 17:53:45	warning
Initializing Channel Timeout Expires - Time the CM can perform initial ranging on all upstream channels in the TCS has expired;CM-MAC=00:26:f3:6d:a9:80;CMTS-MAC=00:01:5c:31:fd:57;CM-QOS=1.1;CM-VER=3.0;	2012/07/03 17:53:45	warning
No Ranging Response received - T3 time-out;CM-MAC=00:26:f3:6d:a9:80;CMTS-MAC=00:01:5c:31:fd:57;CM-QOS=1.1;CM-VER=3.0;	2012/07/03 17:53:26	critical
Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=00:26:f3:6d:a9:80;CMTS-MAC=00:01:5c:31:fd:57;CM-QOS=1.1;CM-VER=3.0;	2012/07/03 17:51:13	critical
DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=00:26:f3:6d:a9:80;CMTS-MAC=00:01:5c:31:fd:57;CM-QOS=1.1;CM-VER=3.0;	2012/07/03 04:11:26	error
Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=00:26:f3:6d:a9:80;CMTS-MAC=00:01:5c:31:fd:57;CM-QOS=1.1;CM-VER=3.0;

[EG]

Basically, they show that there are RF signal / connection quality issues (impairments) between the modem and the CMTS (Cable Modem Termination System) at the local headend facility. The devices are having difficulty talking to / hearing each other;

"3-Critical R2.0 No Ranging Response received - T3 timeout:
 
Explanation. The cable modem has sent 16 Ranging Request (RNG-REQ) messages without receiving a Ranging Response (RNG-RSP) message in reply from the CMTS. The cable modem is therefore resetting its cable interface and restarting the registration process. This typically is caused by noise on the upstream that causes the loss of MAC-layer messages. Noise could also lower the signal-to-noise ratio (SNR) on the upstream to a point where the cable modem's power level is insufficient to transmit any messages. If the cable modem cannot raise its upstream transmit power level to a level that allows successful communication within the maximum timeout period, it resets its cable interface and restarts the registration process.
Recommended Action No action is needed if this is an occasional problem. Check the upstream transmit power for the cable modem to see if it is at or near the maximum allowable levels. Check the RF plant for cabling or connector issues that could generate sufficient noise to lose MAC-layer management messages.
 
3-Critical H501.8 HFC: T4 Timer Expired:
 
Explanation. The cable modem did not receive a station maintenance opportunity in which to transmit a Ranging Request (RNG-REQ) message within the T4 timeout period (30 to 35 seconds). The cable modem is resetting its cable interface and restarting the registration process. Typically, this indicates an occasional, temporary loss of service, but if the problem persists, check for possible service outages or maintenance activity on this particular headend system.
Recommended Action for your Provider: Check the configuration on the CMTS. Check the cable plant for RF connector or cabling issues that could be generating noise on the downstream and upstream.



T4 ( Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received )

Explanation: The cable modem did not receive a station maintenance opportunity in which to transmit a Ranging Request (RNG-REQ) message within the T4 timeout period (30 to 35 seconds). The cable modem is resetting its cable interface and restarting the registration process. Typically, this indicates an occasional, temporary loss of service, but if the problem persists, check for possible service outages or maintenance activity on this particular headend system. This error message is DOCSIS event message is R04.0, Ranging Request.

Why Do Cable Modems Drop Offline?
A Cable Modem requires three main things to remain online once it is connected and operational:

Clean RF plant with a carrier-to-noise consistently above 30dB in the Upstream, and above 33dB in the downstream.

Unicast polls from the CMTS every 30 seconds (keepalives). These are unicast transmit opportunities for this modem's assigned SID, in which it can send a RNG-REQ to the CMTS. If the cable modem does not receive a unicast transmit opportunity within T4 seconds (30 seconds) it has to time out and re-initialise it's MAC layer. So if there is a problem (RF) in the downstream, the cable modem might not "see" this unicast transmit opportunity, and drop offline.

If the CMTS does not get a reply from the CM to the unicast transmit opportunity, the CMTS will poll the modem 16 times in short succession in order to try and get an answer. The modem is considered offline by the CMTS if there is no reply after these retries."

[INTOXSICKATED]

Interesting stuff there EG, thanks for the reply.

I have these errors once a week.  Sometimes I just lose my internet for 10-15 minutes or so, then everything restores and starts running great again.  Other times it's out until I wake-up the next morning though.  In some cases, the internet is out until I or a tech replaces the modem.  

I've never had a problem during the daytime, only at nights.  If I'm getting interference or noise from a neighbor, am I basically screwed?  Also, when I have these problems, what's usually an acceptable amount of time to wait before my service is restored?

[EG]

---

INTOXSICKATED wrote: 

If I'm getting interference or noise from a neighbor, am I basically screwed?

---

If the premise facing techs can not find / fix a problem at your home then it is they who are responsible to escalate it to the line / maintenance dept. techs to investigate the neighborhood infrastructure.

[INTOXSICKATED]

The Comcast customer service tech I spoke with on the phone last night seemed like she knew what she was talking about and was a bit more helpful than others I've talked to in the past.  

She was able to see that there was clearly some sort of problem going on from her end.  She mentioned having a line tech come out and was making notes for a supervisor or something to look at.  I guess that I'll have to push for a line tech if nothing comes out of my appointment tomorrow.

[SGTAngry]

If you don't mind me asking where are you located?

I'm in the Emeryville / Oakland CA. area, and what you've described sounds like exactly the same issues that I've been dealing with since late March. I can't imagine 2 years...I'll move my apt and be long gone with some other provider before that. 

I've been in direct contact with a field / line tech for the last couple of months, and they thought they had discovered the issue - and things were slightly better after it was addressed. However, it's now some other issue and they're trying to figure it out...I've posted a few threads on here about it, but I've stopped for the most part now that I've got the tech contact. Good luck. I'll check back in here and see how things go, and if I ever get a resolution I'll post an update and as much info as I can.

[INTOXSICKATED]

Hey SGT, I'm in tri-valley / Pleasanton area.  

I have a tech coming out today and we'll see what happens.  Right now everything is running great though, so I'm guessing nothing will come of it.  Hopefully I can get a line tech to look at things too.  

[dtdionne]

I was told that there were over 900 connected in my node

[INTOXSICKATED]

The Comcast tech came out and replaced my modem again.  He was a nice guy, he told me to monitor the connection and give him a call if any problems were to come about.  He said that together, we'll get this fixed!  I found it a little odd that he never tested my signal strength or anything like that.  He just swapped out the modem and left.  Well, he tried to leave at least.  He came back about 15 minutes later and asked if I had jumper cables to get his van started.  

Anyways, I went through a period of about an hour (after he left), where I couldn't do much of anything.  Not right after he left, but about an hour after that.  Does that makes sense?  LOL  Web pages were slow, gaming was out of the question, and my speed tests just showed numbers that were way out of whack.  All of the sudden though, it's better now.  I'll give him a call tomorrow and let him know what happened and see what he says.  

Just a suggestion.  And I know this isn't the right place for it, but if Comcast ever decides to put on their own reality show, following their techs around in the call center and in the field would probably provide non stop entertainment.