Comcast Support Problems – SURFboard SBG6580 – Intermittent Connection Loss

December 3, 2011

Last night I finally got fed up with the frequent momentary disconnects that I was experiencing with Comcast. The cable modem/gateway device I have is a Motorola SURFboard SBG6580. I purchased this modem from Amazon after researching which models were supported by Comcast using the information on this page. Device details are available here. It is important to note that this is a currently supported option for connecting to the Comcast network.

Here is some information about the modem, as reported by accessing the web interface to the modem.

Standard Specification Compliant	DOCSIS 3.0
Hardware Version	1
Software Version	SBG6580-3.1.0.0-GA-07-180-NOSH
Cable Modem MAC Address	ff:ff:ff:ff:ff:ff
Cable Modem Serial Number	324369118008466559530006
CM certificate	Installed

Looking in the logs of my gateway device I noticed a number of critical error messages. Below is an excerpt of the logs currently on my device. One of the errors that comes up repeatedly is a T3 time-out. If you run google searches on this you will learn that many Comcast subscribers (and other cable providers too) see this error in conjunction with intermittent disconnects from their service.

I have reproduced the log of errors from the modem at the bottom of this post.

After a lot of reading of forum posts on http://forums.comcast.com I have learned that many people have similar issues.

What all of these have in common is that after repeated suggestions from Comcast that it was a modem issue or an in-house wiring issue, and after customers in some cases spent money to swap out hardware, none of that helped to resolve the issue. The issue is most likely something upstream of the house, but other possibilities exist too.

Some have suggested that the firmware on this model is very old (and riddled with bugs) and that Motorola has made a number of updates to the firmware. You can read an interesting thread about trying to get the firmware upgraded here.

I found references to the following firmware versions being available from Motorola to the carriers.

  • SBG6580-3.2.1.0-GA-02-249-NOSH
  • SBG6580-3.3.0.0-GA-06-022-NOSH

Every networking device except a basic switch or hub has firmware in it that can be field upgraded. Most knowledgable customers are aware of this and have probably done at least one firmware upgrade of a networking device. The Motorola SURFboard 6580 is no different. The firmware can be upgraded. The problem is, Motorola will not provide the firmware to end consumers. Here is a support document from Motorola about their cable modems and the policies about firmware upgrades. To quote,

We apologize about the inconvenience, but your Motorola modem does not support manual upgrades. Motorola is not allowed to control the upgrades of DOCSIS devices, per the standards specification. Any firmware or software changes must be implemented via the cable network. Your cable provider can update the firmware based on what they have approved for their network distribution. Because of that Motorola is not capable of installing firmware for cable modems. Please contact the cable operator to obtain information on upgrading firmware on the cable modem.

Repeated calls to Comcast Customer Service (1-800-XFINITY / 1-800-934-6489) got me no where. I spent approximately two hours on the phone with them. I was disconnected three times, had it suggested to me that the problem was the modem multiple times and was offered the option of paying them for Signature Support, but at no time were they able to actually provide me with updated firmware for the modem.

  • They were able to remotely reset the modem.
  • They studied the connection history and noted that indeed the line had been failing intermittently.
  • They were not at all interested in the content of the log messages I shared below.
  • They could not offer any explanation for the log messages.

In summary, they were no help what so ever.

After reading about lack of firmware upgrades and my experience with their customer service folks I began to question whether Comcast Cares(™) about subscribers at all.

I wonder how many Comcast subscribers have similar problems with intermittent connection loss and just live with it. A survey of forum posts on their own site seems to indicate that the issues are wide spread.

This is truly a terrible situation. Customers purchase devices that Comcast recommends and then when something goes wrong with the service they place all of the blame on the in-house equipment and offer no support what so ever. The cable service providers have things structured such that consumers cannot get support for the devices from the manufacturers because that is the “service agreement” between the manufacturers and cable providers. Customers get squeezed in the middle without any recourse.

According to another site there are known problems with the Motorola SURFboard, especially with VOIP. I suspect these problems could be addressed with a firmware update, but we have already established that Comcast is in no mood to provide the necessary updates.

As a last-ditch effort I am now going to place the SURFboard SBG6580 into bridge mode and use a separate router. I found instructions for doing this on Anthony Volodkin’s blog, here. I will use my Apple AirPort Extreme (which Apple happily provides firmware updates for) as my router.

In a few days/weeks I will post a follow-up to let people know if this solved the intermittent connection loss problems.


 TLV-11 - unrecognized OID;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.1;CM-VER=3.0; 
 Resetting the cable modem due to docsDevResetNow 
 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.1;CM-VER=3.0; 
 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.1;CM-VER=3.0; 
 Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.1;CM-VER=3.0; 
 No Maintenance Broadcasts for Ranging opportunities received - T2 time-out;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.1;CM-VER=3.0; 
 No Ranging Response received - T3 time-out  
 REG RSP not received;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.1;CM-VER=3.0; 
 No Maintenance Broadcasts for Ranging opportunities received - T2 time-out;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.0;CM-VER=3.0; 
 No Ranging Response received - T3 time-out
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 No Maintenance Broadcasts for Ranging opportunities received - T2 time-out;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.0;CM-VER=3.0; 
 No Ranging Response received - T3 time-out  
 No Maintenance Broadcasts for Ranging opportunities received - T2 time-out;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.0;CM-VER=3.0; 
 No Ranging Response received - T3 time-out  
 No Maintenance Broadcasts for Ranging opportunities received - T2 time-out;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.0;CM-VER=3.0; 
 No Ranging Response received - T3 time-out  
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 
 Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.1;CM-VER=3.0; 
 Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.1;CM-VER=3.0; 
 SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.1;CM-VER=3.0; 
 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.1;CM-VER=3.0; 
 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.1;CM-VER=3.0; 
 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.1;CM-VER=3.0; 
 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.1;CM-VER=3.0; 
 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.1;CM-VER=3.0; 
 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.1;CM-VER=3.0; 
 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.1;CM-VER=3.0; 
 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.1;CM-VER=3.0; 
 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.1;CM-VER=3.0; 
 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.1;CM-VER=3.0; 
 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.1;CM-VER=3.0; 
 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.1;CM-VER=3.0; 
 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.1;CM-VER=3.0; 
 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.1;CM-VER=3.0; 
 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.1;CM-VER=3.0; 
 Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.1;CM-VER=3.0; 
 No Maintenance Broadcasts for Ranging opportunities received - T2 time-out;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.1;CM-VER=3.0; 
 No Ranging Response received - T3 time-out  
 No Ranging Response received - T3 time-out  
 No Maintenance Broadcasts for Ranging opportunities received - T2 time-out;CM-MAC=ff:ff:ff:ff:ff:ff;CMTS-MAC=00:01:5c:24:f1:45;CM-QOS=1.0;CM-VER=3.0; 
 No Ranging Response received - T3 time-out    

Comments

  • bakk0020

    Any update? i’m experiencing the exact same issue and run around.

  • http://www.idevelopsoftware.com Bennett Smith

    No update from Comcast. All I get from them is the run around too.  My feeling is that there is a problem with this device and that an update of the firmware would address it. Unfortunately that doesn’t seem to be something Comcast is interested in providing.

    I still need to try the bridge mode experiment. Once I try that I will post an update.

  • Jase

    I am having the same problem with my Comcast and SBG6580. Just got the same run-around from Comcast about the firmware. Mine shows SBG6580-3.1.0.0-GA-07-180-NOSH and clearly this is not the latest. If anyone comes up with a way to upgrade the firmware or some kind of acknowledgement from Comcast I’d like to know. 

  • chakradhar sirigiri

    Im also having the same problem for quite some time. got SBG6580 in March, after couple of months onwards until now I’m facing intermittent connection issues. i either reset the modem on my own / or ask comcast to send the reset signal. this would solve the issue for some time and after that the story repeats. i just called them they said per their records the latest firmware that they see in their system is 3.1.0. It seems they are not aware of the 3.2/ 3.3.
    I’m almost convinced to go back to my modem + router setup solution (instead of current gateway setup).. however will do that after a month or so.

    Admin/Smith request to update us on your experiments

  • mtsucks

    I have the same exact issue SBG6580 DOCSIS 3.0 AND I am also experiencing Internet dropping out issue. The modem keeps resetting also.

  • Karl

    I had all these problems and unchecked the flood control in the Firewall on Monday (based on a comment I found in a Comcast post), and all these issues disappeared. 

    It appears Comcast went in and did a factory reset of my modem, because the password reverted to ‘motorola’ and Flood control was checked again when I came home from work today.  I did tell them I unchecked this box (thinking ‘gee, maybe they can use this info to stop the madness detailed above’, so I don’t know if they reset my modem because I told them or because there is some auto checker that comes around and resets things when the Flood settings are changed.  

    I asked Motorola what this setting did and what risk I was taking by turning it off and they said: 

    The SBG6580 Gateway includes a built-in firewall feature called IP Flood Detection, which is enabled by default.  IP Flood Detection detects and blocks packet floods originating on both the LAN and WAN.  It is DoS (Denial of Service) protection mechanism that will monitor packets for Denial of Service attacks.  Any offending packets may be discarded if it is determined to be a DoS attack.  When IP Flood Detection is enabled, the Super Hub has the ability to block malicious devices that are attempting to flood devices. 

    So they didn’t talk about the risk on my side – they engineers at work think this setting protects Comcasts — while completely mangling the experience on my side.   

  • Rwbbrown

    I am having the same problem with SBG6580 and Comcast in the Seattle area.  I don’t understand much about how modems work, but I guess I will investigate. I spent a lot of money on this modem and it seems like a waste of money. Not sure what action to take

  • Nikkolai Davenport

    Thanks for posting your research!

    @8884c161657c7a417ebcddcbae6c71b1:disqus Thanks for the IP Flood Detection suggestion. That did the trick!

  • William Zeallor

    I got a good answer from Concast about this. A Comcast employee from the regional office called me Saturday and today. I was told that it was a device problem that might be fixed by the recent firmware. But that the firmware on our devices can’t be updated because Comcast has yet to approve the recent firmware. I was told that that’s Comcast’s problem in part because the SBG6580 is listed as a compatible device and, right now, it’s not compatible.

    So, I was given three recommendations:  return it, bridge it, or deal with it and Comcast might eventually approve the updates. The gentleman I spoke with said that he plans to pursue it farther.

    I personally don’t think they’ll yank the compatibility. If more people complain, the more likely it is that Comcast will update. I initiated the discussion with the Comcast employee by emailing We_Can_Help@cable.comcast.com with my signal levels, my account number, and my phone number. I had to be clear that I didn’t want another tech. to come and check the lines and that it’s Comcast who has to update the firmware and not Motorola.

  • Fratty

    Same thing here.  We’ve got an ASUS router coming today and we’re going to use that.  Not only does the 6580 drop out and need resetting, when it is working, its range is abysmal.

  • Jackson2street

    I am also having the same problem with this modem and Comcast in Seattle.  I will try the IP Flood Detection suggestion.  Thought it was my PC laptop but my wireless connection is fine with a Macbook Pro, Android Tablet, and Android phones.  Even streaming to my tv (hard -wired) works great.  But my main laptop has that intermittent connection which has gotten worse with each web page taking 2-4 refreshes to pull something up.  Sometimes only Craigslist works.

  • Ulysses

    My problems also began in December. I always reset and uncheck the IP flood detection because the first time it happened I also found that the IP Flood Detection had been re-checked. I didn’t know about the firmware update.

  • http://profile.yahoo.com/ILL4HKTXKHCQE3IUJ5GSCRFGTQ Rumple

    I am having the same intermittent disconnects several time a day. I can reset it myself by unplugging and then plugging it back in, have Comcast reset it, or do it by the HTTP network mangament port. But it continues to drop.  I put it online in October, put up with it for a month, saw lots of peopel were having the same problem and then put my SB6120 back online where it’s 100% solid.  Comast came out several times, made some BS changes, never had good service.

    This month tried to put the SBG6580 back online…same situation.  Tried to explain to the techs that I needed an update of firmware.  They said all they can do was reset the modem.  Wanted me to reset my modem, stand on my right foot, spins around three times (as long as it was a leap year month and try again).  They wanted to send someone out,  I told them they were working on the wrong problem.  ALL I NEED IS AN UPDATE.  I asked for an elevation, got four or five calls, it went up the elevation then down. 

    The final call was:  “We do not push an firmware to any modems at any time” (This is complete BS and I told them so).  But the result is, my modem is in a drawer, I’m using my old SB6120 and I’ll monitor this site for anyones success.

    COMCAST DOED NOT INTEND TO PROTECT YOUR INVESTMENT.

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