Troubleshooting a very slow Comcast internet connection

[onyxx]

I've searched a bit in these forums while collecting this data and am suspicious of my second "bounce" in my tracert results. Could this be a cabling problem (connection to comcast?)

thanks, onyxx

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For the last week or so I’ve experienced intermittent periods (1 hour to 6 hours or more) when I’ve had extremely slow internet connection speed – to the point where even browsing the web is tedious (took 5 min to register for these forums).

I have Comcast internet – phone – tv.
My modem/telephony device is an Arris TM502G

I have called Comcast 3 times and have been told to disconnect my router, plug computer directly in to it, reset the modem, etc. I’ve powered it down and removed the battery and let it sit for a while, but that didn’t help either. Then, with no real known reason, things improve again for a while.

I have read this site as much as possible with this slow connection and have tried a few things. I’ve use TCPOptimizer to set TCP/IP configuration, disconnected my router completely (to remove possibility that it’s interfering), checked internal wires and such to make sure everythign is hand tight and not crimped or folded. Nothing obvious emerged. I'm in the top floor of an apartment so the external wires are not anything I've been able to inspect.

When I ping a popular site, I get a lot of lost packets:
Pinging www.yahoo-ht3.akadns.net [209.131.36.158] with 32 bytes of data:

Reply from 209.131.36.158: bytes=32 time=32ms TTL=51
Request timed out.
Request timed out.
Reply from 209.131.36.158: bytes=32 time=31ms TTL=52
Reply from 209.131.36.158: bytes=32 time=31ms TTL=51
Reply from 209.131.36.158: bytes=32 time=29ms TTL=52
Reply from 209.131.36.158: bytes=32 time=32ms TTL=51
Request timed out.
Reply from 209.131.36.158: bytes=32 time=31ms TTL=51
(… truncated output but the results pretty much the same, about 1/5 timed out)

Ping statistics for 209.131.36.158:
Packets: Sent = 132, Received = 109, Lost = 23 (17% loss),
Approximate round trip times in milli-seconds:
Minimum = 28ms, Maximum = 36ms, Average = 30ms
Control-C

When I do tracert –h30 www.yahoo.com I get the following:
Tracing route to www.yahoo-ht3.akadns.net [209.131.36.158]
over a maximum of 30 hops:

1 6 ms 5 ms 5 ms 73.246.216.1
2 5 ms * 6 ms ge-3-6-ur01.bellevue.wa.seattle.comcast.net [68.
85.240.249] 3 * 7 ms 7 ms te-9-3-ar01.burien.wa.seattle.comcast.net [68.86
.96.66]
4 8 ms * 7 ms te-9-1-ar02.burien.wa.seattle.comcast.net [68.86
.96.170]
5 8 ms 7 ms 7 ms te-8-1-ar02.seattle.wa.seattle.comcast.net [68.8
6.96.134]
6 11 ms 13 ms 19 ms COMCAST-IP.car1.Seattle1.Level3.net [4.79.104.10
6]
7 13 ms 11 ms 12 ms te-3-2.car1.Seattle1.Level3.net [4.79.104.105]
8 10 ms 9 ms * ae-23-54.car3.Seattle1.Level3.net [4.68.105.100]

9 27 ms 27 ms 27 ms 4.79.106.26
10 28 ms 27 ms 27 ms ge-0-2-0.pat2.swp.yahoo.com [216.115.110.33]
11 30 ms 31 ms 32 ms so-1-0-0.pat1.pdx.yahoo.com [216.115.110.39]
12 30 ms 34 ms 30 ms so-3-0-0.pat1.sjc.yahoo.com [216.115.110.36]
13 28 ms 27 ms 29 ms g-1-0-0-p160.msr1.sp1.yahoo.com [216.115.107.61]

14 29 ms 37 ms 28 ms te-8-1.bas-a1.sp1.yahoo.com [209.131.32.17]
15 35 ms * 33 ms f1.www.vip.sp1.yahoo.com [209.131.36.158]

Trace complete.


From the status page for modem (http://192.168.100.1/)

Status:
RF Parameters
Downstream
Freq/Power: 567.000 MHz 4 dBmV
Signal to Noise Ratio: 36 dB
Modulation: QAM256

--------------------------------------------------------------------------------
Upstream
Freq/Power: 31.008 MHz 42 dBmV
Channel Type: DOCSIS 1.x (TDMA)

Symbol Rate: 2560 kSym/sec

Modulation: QAM16

Status
System Uptime: 0 days 0h:37m:16s
Computers Detected: 1
CM Status: Telephony-AC Power Iso OFF Reg Complete
Time and Date: WED JAN 16 23:42:39 2008

Interface Parameters
Interface Name Provisioned State Speed MAC address
LAN Enabled UP 100 (Full) 00-15-A2-BD-A9-9F
CABLE Enabled UP ---- 00-15-A2-BD-A9-A0
USB Enabled DOWN 12 00-15-A2-BD-A9-A2
MTA passWithWarnings UP ---- 00-15-A2-BD-A9-A1

HW/FW Versions:
CM Hardware Information

System: ARRIS DOCSIS 1.1 / PacketCable 1.0 Touchstone Telephony Modem HW_REV: 02
VENDOR: Arris Interactive, L.L.C.
BOOTR: 5.01
SW_REV: 5.0.50G
MODEL: TM502G
Product Type: 00000006 010a3aa2
Product Release: 00000002
Flash Part: AM29LV320MB
Functional Revision: 18
Download Revision: 2
Firmware Revision: 5.0.50G
Serial Number: REMOVED
Battery Charger FW Rev: 02.10

MTA Hardware Information

Mta Serial Number REMOVED
Mta Type Identifier pktc1.0:05210101000201020901010B090305060708090A0B0C0C01000D010110010912020007

Firmware Build and Revisions
Firmware Name: TS050050G_052507_MODEL_4_5
Firmware Build Time: Fri May 25 16:20:19 EDT 2007

Event Log:
DOCSIS(CM) Events
Date Time Event ID Event Level Description
***** 20000200 3 No Ranging Response received - T3 time-out
***** 13000200 3 DHCP FAILED - Request sent, no response
***** 18000200 3 UCD invalid or channel unusable
***** 17000100 3 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing
***** 20000200 3 No Ranging Response received - T3 time-out
***** 13000100 3 DHCP FAILED - Discover sent, no offer received
***** 20000200 3 No Ranging Response received - T3 time-out
***** 13000100 3 DHCP FAILED - Discover sent, no offer received
***** 20000200 3 No Ranging Response received - T3 time-out
1/15/2008 22:21 20000400 3 Received Response to Broadcast Maintenance Request, but no Unicast Maintenance opportunities received - T4 timeout
1/15/2008 22:22 20000200 3 No Ranging Response received - T3 time-out
1/15/2008 22:24 20000400 3 Received Response to Broadcast Maintenance Request, but no Unicast Maintenance opportunities received - T4 timeout
1/16/2008 22:46 20000200 3 No Ranging Response received - T3 time-out
1/16/2008 22:58 20000400 3 Received Response to Broadcast Maintenance Request, but no Unicast Maintenance opportunities received - T4 timeout
1/16/2008 22:58 17000100 3 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing
1/16/2008 23:03 20000200 3 No Ranging Response received - T3 time-out
***** 13000401 5 ToD request sent - No Response received
***** 13000403 4 ToD request sent - No Response received
***** 20000400 3 Received Response to Broadcast Maintenance Request, but no Unicast Maintenance opportunities received - T4 timeout
1/16/2008 23:48 20000200 3 No Ranging Response received - T3 time-out

PACKETCABLE(MTA) Events
Date Time Event Level Enterprise Event ID Description MAC Address Endpoint Name
1/1/1970 0:00 5 4115 14 Power Supply Telemetry Log - TELEMETRY NORMAL 00.15.A2.BD.A9.A1
1/16/2008 23:06 5 4115 14 Power Supply Telemetry Log - Temperature Alarm Set to 50 C 00.15.A2.BD.A9.A1 *********************************
1/16/2008 23:06 5 4115 16 MTA TFTP: Successful 00.15.A2.BD.A9.A1 *********************************
1/16/2008 23:06 5 4115 14 Power Supply Telemetry Log - TELEMETRY NORMAL 00.15.A2.BD.A9.A1 *********************************
1/16/2008 23:06 5 4115 3 Voice Line State Change, Line Number = 1, Prev State = OOS_NR_UNPROV, New State = IS_NR 00.15.A2.BD.A9.A1 AALN/1:*********************************
1/16/2008 23:06 5 4115 3 Voice Line State Change, Line Number = 2, Prev State = OOS_NR_UNPROV, New State = IS_NR 00.15.A2.BD.A9.A1 AALN/2:*********************************
1/16/2008 23:06 5 4115 26 MTA PROV: Successful! 00.15.A2.BD.A9.A1 *********************************
1/16/2008 23:06 5 4115 14 Power Supply Telemetry Log - BATTERY TEST SCHEDULED 00.15.A2.BD.A9.A1 *********************************

CM State:
CM State: Telephony-AC Power Iso OFF Reg Complete
Complete Docsis-Downstream Scanning
Complete Docsis-Downstream Ranging
Complete Docsis-Upstream Ranging
Complete Docsis-DHCP
Complete Docsis-TFTP
Complete Docsis-Data Reg Complete
Complete Telephony-DHCP
Complete Telephony-TFTP
Complete Telephony-Reg with Call Server
Complete Telephony-Reg Complete

TOD State:
Retrieved Time of Day

BPI State:
Enabled - Authorized BPI Status

DHCP Attempts to obtain CM IP Address:
1 Attempt(s)

Power Supply Telemetry:
Battery Port Battery Operational Status Battery Part Number
1 TELEMETRY NORMAL 718005

[trogers]

Tracert shows packet losses at hop 2, along the connection line from the modem to the ISP's swtich. Get your ISP tech out to check your line.

[commtech4]

Im a com tech for comcast,
First thing i would do is check all cables, splitters, between your modem and the "tap" ( place the line to your hose connects to the pole or pedistal outside) check for any loose fittings, gold spliters, corroded connections inside of them, or center connecters the wrong length. The center connecters should stick out of the end of the cable connecter about 1 mm. If any of the cables in your house have crimp on fittings or twist on, they need to be replaced. Look for kinks in the cables or holes in the cable jackets. Also i'd replece the network patch cable between your computer and the modem. If you find problems with the cables call up and get cable guard, 4.00$ a month in most areas, the call back and get a tech out to fix the problems. Also do you have an catv amp in your house? If so and it was not installed by comcast, chances are its not up to the task of data transmission, also cheaper amps can inject noise intermitant noise into the cables in your house, even if its not between the modem and the line outside.
Even though the levels on the modems diagnositc page look good, they are not always correct, and will not change fast enough to catch an intermittan connection problem.
Do you have any problems with your phone service? posibly echos or broken up voice?

[Sava700]

Im a com tech for comcast,
First thing i would do is check all cables, splitters, between your modem and the "tap" ( place the line to your hose connects to the pole or pedistal outside) check for any loose fittings, gold spliters, corroded connections inside of them, or center connecters the wrong length. The center connecters should stick out of the end of the cable connecter about 1 mm. If any of the cables in your house have crimp on fittings or twist on, they need to be replaced. Look for kinks in the cables or holes in the cable jackets. Also i'd replece the network patch cable between your computer and the modem. If you find problems with the cables call up and get cable guard, 4.00$ a month in most areas, the call back and get a tech out to fix the problems. Also do you have an catv amp in your house? If so and it was not installed by comcast, chances are its not up to the task of data transmission, also cheaper amps can inject noise intermitant noise into the cables in your house, even if its not between the modem and the line outside.
Even though the levels on the modems diagnositc page look good, they are not always correct, and will not change fast enough to catch an intermittan connection problem.
Do you have any problems with your phone service? posibly echos or broken up voice?

this thread is 2 years old... either he's fixed the problem or went to DSL out of frustration.

[commtech4]

didnt look at date, lol

[macky]

That thread may have been old but I have the same problem. My speeds were always adequate with my old RCA Modem 305, Docsis 1.1. I called Comcast at least five times and they just tell me the modem looks ok. I finally decided to replace the modem with Motorola sb6120. This made only a slight improvement.

I called them and insisted that they send someone to check the line. I am now out $100.00 and still have no resolution. I am contemplating keeping the modem anyway because of the upgrade to Docsis 3 even though it my old modem is supposed to handle downloads up to 30mbps.

Any suggestions will be greatly appreciated.

[Sava700]

That thread may have been old but I have the same problem. My speeds were always adequate with my old RCA Modem 305, Docsis 1.1. I called Comcast at least five times and they just tell me the modem looks ok. I finally decided to replace the modem with Motorola sb6120. This made only a slight improvement.

I called them and insisted that they send someone to check the line. I am now out $100.00 and still have no resolution. I am contemplating keeping the modem anyway because of the upgrade to Docsis 3 even though it my old modem is supposed to handle downloads up to 30mbps.

Any suggestions will be greatly appreciated.

I'm not sure what your problem is?? And yes keep the 6120, it's much better than your old one no matter what happens.



post signal/power data? Also what speed package do you pay for and can you post a few speedtest results? www.speedtest.net also copy and paste results from this pages program:
http://www.cc.gatech.edu/~partha/dif...aperprobe.html


http://192.168.100.1/cmSignal.htm

[rcmz]

*
Well, maybe because your browser and windows system are not compatible, you'd better change your browser or maybe you can try the software tuneup360, which can help you solve all the computer problems.

[Sava700]

*
Well, maybe because your browser and windows system are not compatible, you'd better change your browser or maybe you can try the software tuneup360, which can help you solve all the computer problems.

Umm no that tuneup crap will not help and he's not posted back in nearly 4 months so I imagin he's fixed it already.

[jamho3]

I'm not sure what your problem is?? And yes keep the 6120, it's much better than your old one no matter what happens.



post signal/power data? Also what speed package do you pay for and can you post a few speedtest results? www.speedtest.net also copy and paste results from this pages program:
http://www.cc.gatech.edu/~partha/dif...aperprobe.html


http://192.168.100.1/cmSignal.htm

Sorry I am new here and I was hoping someone might be able to help as I have a similar comcast problem I think my speed package is 6mb

Here is a speedtest result:








http://www.speedtest.net/result/1085915267.png




DiffProbe beta release. October 2009. Build 1002.
Shaper Detection Module.

Connected to server 4.71.210.226.

Estimating capacity:
Upstream: 725 Kbps.
Downstream: 5324 Kbps.

The measurement will take upto 2.5 minutes. Please wait.

Checking for traffic shapers:

Upstream: Measurement aborted due to high packet loss rate.

Downstream: No shaper detected.
Median received rate: 5226 Kbps.

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


Can anyone help?

Thanks in advance.

[Sava700]

would have been better if you made your own thread... perhaps diong that and posting signal levels on your modem?

[jamho3]

would have been better if you made your own thread... perhaps diong that and posting signal levels on your modem?

Oh sorry, I'm new. I will do that... After some more checking.

[jacksonstewart]

Hello every one..
I am new here and hoping someone might be able to help as I have a problem to run...

[kindness]

Out of nowhere, I was having excruciatingly slow internet speed on Comcast. The Comcast tech advised that my Motorola SB 4100 was at the "end of life" and that I should upgrade. Skeptical, I purchased this modem which is a DOCSIS 3.0 (and backwards compatible) modem. It worked. I went from a 2mbps download speed to over 17mbps. What a difference. There was one installation glitch that you need to be aware of. When you hook up the modem (connect the coax cable, connect the ethernet cable, and plug it in, that's it), and then try to get online, it will direct you to a Comcast self-activation screen (no other site is available). After entering my account number and phone number and hitting the "next" button, I got a blank screen, and nothing happens. So I called Comcast and they said that usually happens if you are doing an upgrade; it mostly works only for a new service connection. However, it is a simple matter to give the tech your MAC address and the serial number. After about 5 minutes, while he stayed on the line, it came alive, no problem. BUT, here's the thing: the serial number they need is the CUSTOMER serial number. This is only found on the bottom of the Motorola box the modem came in. This is different from the "S/N" serial number that is on the label that is on the instruction sheet and on the bottom of the modem itself. The customer S/N has letters in it; the regular S/N has only numbers in it and is too long. My first Comcast tech didn't know that and it took a day to sort it out. Other than that, it works well with my iMac and Apple Airport Extreme Base wireless router. Enjoy

Link to Modem: http://amzn.to/ApAfjg