Intermittent connection issues

The signal stat figures are o-k / in spec.

It seems that your image of the error log entries has been deleted due to it containing your modem's CM MAC address which is considered to be personal information. Personally identifying information is a violation of their forum guidelines.

What you can do is copy and paste all of the text (instead of using an image) but you'll need to redact all of the CM MAC and CMTS MAC addresses.

I am having the same issue and in my modems event log I noticed a bunch of T3 and T4 timeout issues.  I found this info helpful.  I am still trying to get a tech from xfinity to visit my place...

T3 ( Ranging Request Retries Exhausted )

Explanation: The cable modem has sent 16 Ranging Request (RNG-REQ) messages without receiving a Ranging Response (RNG-RSP) message in reply from the CMTS. The cable modem is therefore resetting its cable interface and restarting the registration process. This typically is caused by noise on the upstream that causes the loss of MAC-layer messages. Noise could also raise the signal-to-noise ratio (SNR) on the upstream to a point where the cable modem’s power level is insufficient to transmit any messages. If the cable modem cannot raise its upstream transmit power level to a level that allows successful communication within the maximum timeout period, it resets its cable interface and restarts the registration process. This error message is DOCSIS event message is R03.0, Ranging Request.

T3 timeouts result when a Cable Modem, that is locked into the downstream, transmits a Ranging Request(RNG-REQ) to the CMTS(Cable Modem Termination System) and 200 milliseconds passes without the CM receiving a Ranging Response(RNG-RSP) from the CMTS. Indeed, maintaining a PING(Packet InterNet Groper) less than 200ms is important to a healthy DOCSIS network. When 10 T3s occur in succession (a period of 20 seconds passes without the CM receiving a Ranging Response, the CM will cease attempting to communicate with the HFC(Hybrid Fiber Optic Coaxial) network and reset its DOCSIS interface. In this case the RESET statistic on the modem log will increment but not all T3s will cause a reset if communication is restored within 10 T3 periods or 20 seconds. When T3 timeouts occur, but not enough occur in succession to trigger a reset, slow speeds are often a symptom as these timeouts slow down the TCP/IP handshakes necessary to maintain internet connections.

T3 Timeouts are typically caused by Upstream Noise causing Ranging Requests to not be clearly received by the CMTS. T3 problems can often be intermittant in nature as they may be the result of noise originating in any part of the plant that shares the same line card at the CMTS with the subscriber impacted. In fact, T3s can even be caused by noise originating on other neighboring nodes if resources are shared at the headend. Speed issues and intermittant connectivity issues are some of the most common problems encounted on our Trouble Calls.

T3 Timeouts can also be encountered when the plant's noise floor is so severe that the CM cannot overtalk it (SNR is bad and Noise power level is higher than your modem's signal). This can affect a single leg of the plant or even entire nodes. When a high noise floor results in several modems resetting their DOCSIS interface because 10 T3 timeouts have occured in succession, as we covered above, this is referred to as a noise outage. Noise outages frequently occur node-wide and while some may self-clear, many continue until a Plant Maintenence Technician locates and repairs the offending source of noise. This is why we ALL must be vigilant about preventing noise from entering the plant.

Occurrence: Extremely common in the customer homes

Symptom: Will cause intermittent disconnections. If you see couple of them, it is fine. If you quite a few of them consecutively, then it will lead to disconnections.

Fixes:
1. Check for the loose or Bad cables. This is by far most neglected and most common fix.
2. Remove extra splitters in house
3. Buy powered amplifier to boost your upstream power
4. Buy better coaxial cables
5. Call for a technician visit to inspect and fix cables outside and inside home (could be rain damage, fire damage, animal damage, construction damage, etc)

T4 ( Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received )

Explanation: The cable modem did not received 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. This error message is DOCSIS event message is R04.0, Ranging Request.

T4 Timeouts result when a CM does not receive a Station Maintenance Opportunity in which to transmit a Ranging Request within the T4 timeout period which is approximately 30 seconds. T4s typically result from an impairment in the downstream. As they take an interruption in connectivity for 30 seconds to occur and trigger a reset, T4s can be indicative of major faults like damaged drops, or mainline suckouts but can also occur from maintenance work in the plant or at the headend as well. A low T4 count may be indicative only of repeated maintenance operations while a high T4 count may represent a severe plant or drop impairment.

Occurrence: Extremely common in the customer homes

Symptom: Will cause disconnections every time it occurs.

Fixes:
1. Check for the loose or Bad cables. This is by far most neglected and most common fix.
2. Remove extra splitters in house
3. Buy powered amplifier to boost your upstream power
4. Buy better coaxial cables
5. Call for a technician visit to inspect and fix cables outside and inside home (could be rain damage, fire damage, animal damage, construction damage, etc)
6. Check for any noise sources

Hello @Jesse28! We really do appreciate you taking the time to write out this detailed post to let us know of the service issues you are running into. We know that having a working connection is crucial these days, especially when you are working from home, so we want to ensure that this is taken care of ASAP. We'd like to get your account pulled up so we can check out some signals and run diagnostics to help us determine exactly what is causing this. Can you please hit the chat icon in the top right-hand corner of the screen, click "new message", type "Xfinity Support" and select that profile to send us a message directly so we can further assist you with this?

Thank you so much for sending this our way @EG!

@XfinityKatieMS Quite welcome ! :-)

Glad you got it squared away ! Now closing your topic.