Intermittent T3 Timeouts - Xfinity Help and Support Forums

sdenley · ‎08-25-2020

Currently I have Xfinity TV and internet (300 Mbps) with my own Netgear Nighthawk CM1200. I am having intermittent (ranging from minutes to hours) loss of internet connectivity due to T3 time-outs and varying internet speeds of .4 to 360 Mbps After spending hours and hours going through the automated support service, waiting for numerous callbacks, multiple modem resets, support reps blowing me off after a successful reset and two service technicians, I am still experiencing the same problems. I’ve contacted Netgear and they confirmed from the modem event log that my modem has normal upstream power levels and advised that I contact a level 3 support from the ISP. When I finally got in touch with a level 3 support person (nearly waiting 8 hours for a callback) all they did was schedule the second technician to come out. The first technician replaced a 4-way splitter in my house with a 2-way splitter (one output going to the DVR and the other to the modem) and tightened the connections on the outside cable pedestal box. The second technician ran a new cable from the outside cable pedestal box to cable termination box at the exterior of the house and verified that it is properly grounded. I’ve currently been testing the modem using the cable from the cable termination box directly to the modem and still have intermittent interruptions. I know that troubleshooting intermittent problems are difficult, but the constant internet interruptions makes your internet service that I am paying for totally useless.

Below is the modem log event

Time	Priority	Description
Tue Aug 25 10:29:59 2020	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Tue Aug 25 09:15:59 2020	Notice (6)	CM-STATUS message sent. Event Type Code: 24; Chan ID: 33; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0 1 2 3.;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Tue Aug 25 09:15:37 2020	Notice (6)	CM-STATUS message sent. Event Type Code: 24; Chan ID: 33; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0 2 3.;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Tue Aug 25 09:15:33 2020	Notice (6)	CM-STATUS message sent. Event Type Code: 22; Chan ID: 33; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Tue Aug 25 09:15:31 2020	Notice (6)	CM-STATUS message sent. Event Type Code: 23; Chan ID: 33; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Tue Aug 25 09:14:59 2020	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Tue Aug 25 09:13:46 2020	Warning (5)	MDD message timeout;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Tue Aug 25 09:13:46 2020	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Tue Aug 25 09:13:40 2020	Warning (5)	MDD message timeout;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Tue Aug 25 09:13:40 2020	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Tue Aug 25 09:08:24 2020	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Mon Aug 24 22:34:42 2020	Warning (5)	Dynamic Range Window violation
Mon Aug 24 22:34:42 2020	Warning (5)	RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Mon Aug 24 22:34:42 2020	Warning (5)	Dynamic Range Window violation
Mon Aug 24 22:34:42 2020	Warning (5)	RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Mon Aug 24 22:34:42 2020	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Mon Aug 24 22:34:37 2020	Critical (3)	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Mon Aug 24 22:34:37 2020	Notice (6)	DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Mon Aug 24 22:34:32 2020	Notice (6)	TLV-11 - unrecognized OID;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Notice (6)	Honoring MDD; IP provisioning mode = IPv6
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Mon Aug 24 21:12:40 2020	Critical (3)	16 consecutive T3 timeouts while trying to range on upstream channel 2;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Mon Aug 24 21:12:40 2020	Critical (3)	Ranging Request Retries exhausted;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Mon Aug 24 21:12:40 2020	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Mon Aug 24 21:12:10 2020	Notice (6)	CM-STATUS message sent. Event Type Code: 7; Chan ID: 1 2 3 4; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Mon Aug 24 21:12:09 2020	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Mon Aug 24 21:12:07 2020	Critical (3)	16 consecutive T3 timeouts while trying to range on upstream channel 1;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Mon Aug 24 21:12:07 2020	Critical (3)	Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Mon Aug 24 21:12:07 2020	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Mon Aug 24 21:11:56 2020	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Mon Aug 24 21:11:43 2020	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Mon Aug 24 21:11:36 2020	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Mon Aug 24 21:11:29 2020	Notice (6)	CM-STATUS message sent. Event Type Code: 7; Chan ID: 2 3 4; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Mon Aug 24 21:11:19 2020	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Mon Aug 24 21:11:18 2020	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Mon Aug 24 21:11:07 2020	Critical (3)	16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Mon Aug 24 21:11:07 2020	Critical (3)	Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Mon Aug 24 21:11:07 2020	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Mon Aug 24 21:11:06 2020	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;
Mon Aug 24 21:10:55 2020	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=28:80:88:b3:0d:80;CMTS-MAC=00:01:5c:84:ca:79;CM-QOS=1.1;CM-VER=3.1;