Intermittent package loss spikes and disconnects

Crosspost from https://forums.xfinity.com/conversations/your-home-network/intermittent-package-loss-spikes-and-disconnects/657cdd16f961c6163a312b89

Hello everyone

My Xfinity connection's quality has severely degraded and I think it started after an internet outage during one night. The symptom is a huge spike in packet loss (between 10-60%, if it doesn't drop the connection completely) several times a day.

I have tried the usual things (reboots, firmware resets, check all connections, replace wires, etc.), but to no avail, even setting the MTU as low 1364 didn't help, so I've checked the modem (Motorola MB7220) and found a log full of issues; The modem is directly hooked up to the main coax and has been working great until the night in question and the wires haven't been messed with before either, the plan is for 200mbit/s down + 10 up.

Here is a list of issues from the log (after our latest power outage):

Tue Nov 14 20:59:24 2023 Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=<My-CM-MAC>;CMTS-MAC=<My-CMTS-MAC>;CM-QOS=1.1;CM-VER=3.0;
Tue Nov 14 20:59:41 2023 Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=<My-CM-MAC>;CMTS-MAC=<My-CMTS-MAC>;CM-QOS=1.1;CM-VER=3.0;
Tue Nov 14 21:02:50 2023 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=<My-CM-MAC>;CMTS-MAC=<My-CMTS-MAC>;CM-QOS=1.1;CM-VER=3.0;
Tue Nov 14 21:02:57 2023 Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=<My-CM-MAC>;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
Tue Nov 14 21:03:00 2023 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=<My-CM-MAC>;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
Tue Nov 28 05:58:27 2023 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=<My-CM-MAC>;CMTS-MAC=<My-CMTS-MAC>;CM-QOS=1.1;CM-VER=3.0;
Fri Dec 01 11:32:24 2023 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=<My-CM-MAC>;CMTS-MAC=<My-CMTS-MAC>;CM-QOS=1.1;CM-VER=3.0;
Mon Dec 04 11:03:43 2023 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=<My-CM-MAC>;CMTS-MAC=<My-CMTS-MAC>;CM-QOS=1.1;CM-VER=3.0;
Sat Dec 09 00:24:20 2023 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=<My-CM-MAC>;CMTS-MAC=<My-CMTS-MAC>;CM-QOS=1.1;CM-VER=3.0;
Tue Dec 12 15:15:37 2023 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=<My-CM-MAC>;CMTS-MAC=<My-CMTS-MAC>;CM-QOS=1.1;CM-VER=3.0;
Thu Dec 14 12:35:15 2023 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=<My-CM-MAC>;CMTS-MAC=<My-CMTS-MAC>;CM-QOS=1.1;CM-VER=3.0;
Thu Dec 14 12:36:00 2023 Critical (3) SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period;CM-MAC=<My-CM-MAC>;CMTS-MAC=<My-CMTS-MAC>;CM-QOS=1.1;CM-VER=3.0;
Thu Dec 14 12:36:07 2023 Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=<My-CM-MAC>;CMTS-MAC=<My-CMTS-MAC>;CM-QOS=1.1;CM-VER=3.0;
Thu Dec 14 12:36:27 2023 Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=<My-CM-MAC>;CMTS-MAC=<My-CMTS-MAC>;CM-QOS=1.1;CM-VER=3.0;
Thu Dec 14 12:36:43 2023 Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=<My-CM-MAC>;CMTS-MAC=<My-CMTS-MAC>;CM-QOS=1.1;CM-VER=3.0;
Thu Dec 14 12:36:53 2023 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=<My-CM-MAC>;CMTS-MAC=<My-CMTS-MAC>;CM-QOS=1.1;CM-VER=3.0;
Thu Dec 14 12:38:28 2023 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=<My-CM-MAC>;CMTS-MAC=<My-CMTS-MAC>;CM-QOS=1.1;CM-VER=3.0;
Thu Dec 14 12:39:44 2023 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=<My-CM-MAC>;CMTS-MAC=<My-CMTS-MAC>;CM-QOS=1.1;CM-VER=3.0;
Thu Dec 14 12:41:12 2023 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=<My-CM-MAC>;CMTS-MAC=<My-CMTS-MAC>;CM-QOS=1.1;CM-VER=3.0;
Thu Dec 14 12:45:32 2023 Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=<My-CM-MAC>;CMTS-MAC=<My-CMTS-MAC>;CM-QOS=1.1;CM-VER=3.0;
Thu Dec 14 12:45:32 2023 Critical (3) SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=<My-CM-MAC>;CMTS-MAC=<My-CMTS-MAC>;CM-QOS=1.1;CM-VER=3.0;
Thu Dec 14 12:45:33 2023 Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=<My-CM-MAC>;CMTS-MAC=<My-CMTS-MAC>;CM-QOS=1.1;CM-VER=3.0;
Thu Dec 14 12:45:35 2023 Critical (3) SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=<My-CM-MAC>;CMTS-MAC=<My-CMTS-MAC>;CM-QOS=1.1;CM-VER=3.0;
Thu Dec 14 12:48:48 2023 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=<My-CM-MAC>;CMTS-MAC=<My-CMTS-MAC>;CM-QOS=1.1;CM-VER=3.0;
Thu Dec 14 12:49:39 2023 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=<My-CM-MAC>;CMTS-MAC=<My-CMTS-MAC>;CM-QOS=1.0;CM-VER=3.0;
Thu Dec 14 12:50:26 2023 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=<My-CM-MAC>;CMTS-MAC=<My-CMTS-MAC>;CM-QOS=1.0;CM-VER=3.0;
Thu Dec 14 12:51:09 2023 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=<My-CM-MAC>;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
Thu Dec 14 12:51:10 2023 Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=<My-CM-MAC>;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
Thu Dec 14 12:51:11 2023 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=<My-CM-MAC>;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
Thu Dec 14 12:51:30 2023 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=<My-CM-MAC>;CMTS-MAC=<My-CMTS-MAC>;CM-QOS=1.0;CM-VER=3.0;
Time Not Established Notice (6) Honoring MDD; IP provisioning mode = IPv6
Fri Dec 15 14:11:21 2023 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=<My-CM-MAC>;CMTS-MAC=<My-CMTS-MAC>;CM-QOS=1.1;CM-VER=3.0;

According to several other posts i found, this could be due to the power of my upstream; If that's the case, would that be something I could somehow lower (e.g. by adding some resistance via some splitter) or is this something for Xfinity's techs? My info looks like this:

EDIT: I don't know if it's just me, but it feels as if it's worse when i'm using my upstream (uploads/streams/etc.) more excessively, maybe that makes sense, considering the potential upstream-power-issue?

Startup Sequence

Startup Step	Status	Comment
Acquire Downstream Channel	459000000 Hz	Locked
Upstream Connection	OK	Operational
Boot State	OK	Operational
Configuration File	OK
Security	Enabled	BPI+

Connection Status

System Up Time	0 days 05h:41m:28s
Network Access	Allowed

Downstream Bonded Channels

Channel	Lock Status	Modulation	Channel ID	Freq. (MHz)	Pwr (dBmV)	SNR (dB)	Corrected	Uncorrected
1	Locked	QAM256	32	459.0	-10.3	39.4	155438	636804
2	Locked	QAM256	41	453.0	-11.8	38.6	129704	346864
3	Locked	QAM256	34	465.0	-10.2	39.4	42945	112
4	Locked	QAM256	35	471.0	-10.0	39.7	8360	1020
5	Locked	QAM256	36	477.0	-9.5	40.3	25165	132
6	Locked	QAM256	1	483.0	-8.5	40.8	12827	150
7	Locked	QAM256	2	489.0	-10.7	39.7	11711	134
8	Locked	QAM256	3	495.0	-10.0	40.2	8910	115
Total							395060	985331

Upstream Bonded Channels

Channel	Lock Status	Channel Type	Channel ID	Symb. Rate (Ksym/sec)	Freq. (MHz)	Pwr (dBmV)
1	Locked	ATDMA	7	5120	22.8	54.0
2	Locked	ATDMA	5	5120	35.6	52.8
3	Locked	ATDMA	6	5120	29.2	54.0
4	Locked	ATDMA	8	5120	16.4	54.0

Responses

XfinityJamesC

Official Employee

•

2.1K Messages

1 year ago

Greetings, @kbob88! I hope your week has been treating you well. Thanks so much for taking a moment out of your busy day to leave a post on our community forum. I'm sorry to hear you're having issues with your connection, but you have definitely come to the right place for assistance.

Your upstream power levels are a little outside the recommended range, which is usually 35 dBmV to 52 dBmV. It's hard to say if that would solely be responsible for the connection issues you've reported, but it is probably the first place we should check.

If you could send our team a direct message with your full name, the name listed on the account (if different), and the service address associated with your account, I'd be more than happy to look into this for you.

To send a Direct Message, please click on the “Direct Message” icon in the top-right corner of the screen, next to the bell icon, click the "New message" (pencil and paper) icon, then type or select "Xfinity Support". Type your message in the text area near the bottom of the window and press Enter to send your message and initiate a live session.

4

0

K

kbob88

5 Messages

@XfinityJamesC Hello James, thank you for your quick reply; I am not going to be home until the end of the year (but would greatly benefit from a stable tunnel connection to my home network); Would this require on-prem access to the device or is this something that can be adjusted remotely/for the closest "distribution point" (sorry, i don't know the correct terminology)?

(edited)

1 year ago

0

XfinityEmilyB

Official Employee

•

2K Messages

That's a great question, @kbob88! This may require a technician to come check your signals on site, which would require someone at least 18 years old to be present. If there's anyone home that could troubleshoot, we can try some steps to improve the connection. Have you checked the coax connection at the back of the modem as well as where it connects to the coax wall plate to make sure both ends are secure? I'm also able to send signals to see if we can improve the connection, but I'll need you to send me a Direct Message so I can access your account.

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Please, mark a reply as the Accepted Answer. tick

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Please, mark a reply as the Accepted Answer. tick

1 year ago

0

K

kbob88

5 Messages

Hello Emily, thank you as well for your response; I'm afraid nobody with the technical expertise is going to be around, so I will wait until I am back to schedule something; To my knowledge there is no wall plate involved or at least i haven't found anything like that and it does indeed seem as if it was the coax that's coming in from the outside / the pole in the backyard (we only need it in the basement for the router, so there was no need for e.g. some kind of splitter ; The wire has been unscrewed several times to make sure that any potential patina gets removed.

1 year ago

0

XfinityEmilyB

Official Employee

•

2K Messages

Gotcha, @kbob88! If you don't have a wall plate, it most likely runs from your modem to the outside splitter. I appreciate you checking the cable already. Please reach back out to us here when you can assist us in troubleshooting the issue so we can narrow down the root cause and find a resolution.

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Please, mark a reply as the Accepted Answer. tick

1 year ago

0

BruceW

Gold Problem Solver

•

26.3K Messages

1 year ago

... Motorola MB7220 ...

Perhaps not the source of the problem, but note that the 7220 is no longer approved for use with Comcast/Xfinity Internet service. See https://assets.xfinity.com/assets/dotcom/projects/cix-4997_compatible-devices/2023.11.22%20Full%20List%20of%20Compatible%20Devices.pdf (from the "All Compatible Devices" link near the bottom of https://www.xfinity.com/support/devices). Consider replacing your 7220 with an approved device.

Please be aware that there are 2 kinds of responses in this Forum: Replies and Comments. When you Comment on a post by scrolling down to "Comment on this post here...", I am notified of your response. But if you select Reply, I am NOT notified and may not be aware of your response.

1

K

kbob88

5 Messages

Hi BruceW, thanks for pointing that out; However, it also reads "Devices not shown on this list are either incompatible with the Xfinity 10G Network or no longer supported by the
device manufacturer.", which means it's unsuitable for 10G, which I am not worried about, or not longer supported by the manufacturer, which unfortunately is rather common for modems and routers and even if they are still "supported", it doesn't imply any kind of regular security patch releases unless things get bad/flaws are being actively exploited.

As long as it checks the boxes (DOCSIS 3.0 is enough for for 100mbit/s), I don't see a good reason why I should contribute to the growing piles of e-waste; I've also got my plan initially with this modem and it was okay for everyone involved and I haven't received a notification about expiring certificates, neither have I read about any security issues with the CPU, DOCSIS standard or the offered services involved, so I should be good (theoretically) for now, having a more than capable firewall in between (and mitm attacks are also pointless in times of TLS everywhere, unless we're talking about something like e.g. terrapin).

1 year ago

0

Your Home Network

kbob88

Intermittent package loss spikes and disconnects

XfinityJamesC

kbob88

XfinityEmilyB

kbob88

XfinityEmilyB

BruceW

Please be aware that there are 2 kinds of responses in this Forum: Replies and Comments. When you Comment on a post by scrolling down to "Comment on this post here...", I am notified of your response. But if you select Reply, I am NOT notified and may not be aware of your response.

kbob88

New to the Community?