Basic Internet Connectivity And Modem Help

[Sunnyvaleguy]

I have been losing sync and having the hard reset the cable modem every few days lately (pull power and cable).  No particular times.  When I DO have connection, speeds seem good.  I called it into comcast they looked at the modem, reset it and no reported issues in our neighboorhood and didn't see anything bad with the modem (of course).  It has been working well over the last year. 

Any suggestions for trouble shooting?

Using a surfboard 5100 (info below).

Thanks in advance.

John

Software Version: SB5100-2.3.8.0-GA-00-NOSH
Hardware Version: 3
MIB Version: II
GUI Version: 1.0
VxWorks Version: 5.4

Downstream    Value
Frequency     747000000 Hz Locked
Signal to Noise Ratio    37 dB
Power Level    0 dBmV

Upstream    Value
Channel ID    3
Frequency     30600000 Hz Ranged
Power Level    47 dBmV

traceroute: Warning: www.comcast.net has multiple addresses; using 184.84.222.66
traceroute to a1526.g.akamai.net (184.84.222.66), 64 hops max, 52 byte packets
 1  192.168.1.1 (192.168.1.1)  1.246 ms  0.649 ms  0.738 ms
 2  67.161.24.1 (67.161.24.1)  71.952 ms  25.167 ms  29.988 ms
 3  te-1-4-ur03.santaclara.ca.sfba.comcast.net (68.86.248.17)  10.703 ms  10.623 ms  9.736 ms
 4  te-1-10-0-7-ar01.sfsutro.ca.sfba.comcast.net (68.85.155.62)  13.463 ms  27.135 ms  12.467 ms
 5  pos-3-2-0-0-cr01.sanjose.ca.ibone.comcast.net (68.86.90.153)  12.481 ms  14.138 ms  14.457 ms
 6  pos-0-3-0-0-pe01.529bryant.ca.ibone.comcast.net (68.86.87.142)  12.988 ms  13.901 ms  12.479 ms
 7  a184-84-222-66.deploy.akamaitechnologies.com (184.84.222.66)  30.966 ms  14.412 ms  12.741 ms

Speedtest - 24Mbps down, 4Mbps up.

2011-09-26 12:08:17    3-Critical    R005.0    Started Unicast Maintenance Ranging - No Response received - T3 time-out
1970-01-01 00:00:27    3-Critical    D003.0    DHCP WARNING - Non-critical field invalid in response.
2011-09-26 12:05:18    3-Critical    R004.0    Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 timeout
1970-01-01 00:01:11    3-Critical    D003.0    DHCP WARNING - Non-critical field invalid in response.
2011-09-26 12:00:22    3-Critical    R004.0    Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 timeout
1970-01-01 00:00:21    3-Critical    D003.0    DHCP WARNING - Non-critical field invalid in response.
1970-01-01 00:01:16    3-Critical    R004.0    Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 timeout
1970-01-01 00:00:49    3-Critical    D003.0    DHCP WARNING - Non-critical field invalid in response.
1970-01-01 00:01:17    3-Critical    R004.0    Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 timeout
1970-01-01 00:00:15    3-Critical    R002.0    No Ranging Response received - T3 time-out
1970-01-01 00:01:34    3-Critical    R004.0    Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 timeout
1970-01-01 00:00:32    3-Critical    D003.0    DHCP WARNING - Non-critical field invalid in response.
1970-01-01 00:01:14    3-Critical    R004.0    Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 timeout
1970-01-01 00:00:33    3-Critical    D003.0    DHCP WARNING - Non-critical field invalid in response.
2011-09-26 11:22:38    3-Critical    R004.0    Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 timeout
1970-01-01 00:01:01    3-Critical    D003.0    DHCP WARNING - Non-critical field invalid in response.
2011-09-26 11:20:19    3-Critical    R004.0    Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 timeout
1970-01-01 00:01:05    3-Critical    D003.0    DHCP WARNING - Non-critical field invalid in response.
1970-01-01 00:01:31    3-Critical    R004.0    Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 timeout
1970-01-01 00:00:49    3-Critical    D003.0    DHCP WARNING - Non-critical field invalid in response.
1970-01-01 00:01:17    3-Critical    R004.0    Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 timeout

[i-am-nerdburg]

Your signal looks good (what we can see of it anyhow.) If you see nothing but T4 errors in the log, it's most likely a bad modem. It would still be a good idea to check all connectors, wiring and splitters tho. If it's a rented modem swap it. If you own the modem you might want to rent one from Comcast just to make sure it's the problem before you buy a new one.

[ComcastSteve]

Agreed with i-am-nerdburg

Swap out the modem. You can find your nearest service/payment center here.

https://www.comcast.com/Localization/Localize.cspx?Referer=%2fcustomers%2fcontactus%2fpaymentcenter%...

[Sunnyvaleguy]

Thanks for the great fast replies.

Is it possible that upstream CC is having problems as well?

Any suggestions for the better cable modems?  I was assuming the Motorola SB6120 SURFboard is a good one?  $80 at amazon.

thx
John

[EG]

FWIW, T4's can also be caused by noise ingress;

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.



[Sunnyvaleguy]

Kudos to each of you.  Thanks.  I ordered the 6120 anyway!  I'll keep you posted.

John

[EG]

I hope that this is a solution for you ! If noise exists you could still have the same problem. Either way, you are getting a newer tech DOCSIS 3 capable modem which should yield better overall performance and reliability.

[jerrygar]

  I had a connectivity issue that took a couple months to resolve, and then it was only by luck an line engineer was actually investigating the line at the time the "intermittent" poblem occured.

  They knew service had been interupted - big deal because you could have told them that. A $2 part was causing intermittent problems and they had no way to know that without actually being there physically at the time of the interuption.

  At least I got all knew inside and outside cable lines as a result. They spent thousands on a $2 part because of this. I wouldn't buy stock in Comcast and am waiting for a decent competitor to emerge.