About dman77

Your cable may be receiving ingress from outdated phone lines or FM signal from nearby cell towers. Check out my post here: https://forums.xfinity.com/t5/Your-Home-Network/Signal-ingress-due-to-outdated-neighborhood-phone-props/m-p/3374867/highlight/true#M335162   To narrow the issue, I recommend hooking up to Ethernet, installing pingplotter.com & then debugging by reading pingplotter's blog. ... View more

@jontalk, I guess I should consider rolling my own modem/router but I do have an update that may point to a deeper issue...   ... A technician came by yesterday & identified the issue to be FM ingress. Here are my notes: He ran a diagnostic and found an ingress problem in the signal. This is signal leakage and can occur when an external signal is interfering into the cable. This results in noise & disruption of the desired signal, usually seen as packet loss. When he started unscrewing the splitter from the cable, he felt an electric shock. He then took out a Foreign Voltage Detector (FVD) that shot up when he brought it next to the cable. This indicated an AC current was going through the wire which it's not supposed to. This led him to conclude that an electric signal was passing through the cable when it shouldn't. Looking at the outside setup, he identified that the neighborhood is still using old phone cable prop boxes. These boxes send an electric signal through the wire since old phone lines needed that. This electric signal is the cause of signal leakage and causes FM ingress in our cable. This manifests as a packet loss in our internet connection which ultimately leads to slower internet connection than what you're paying for. So it seems like an outside network issue is at fault here. To back up this claim, I checked out the modem's 10.0.0.1 & tried to find a pattern in downstream/upstream signals. Here is the table: https://imgur.com/a/qJFMGPq   I used this link as a reference (https://arris.secure.force.com/consumers/articles/General_FAQs/SB6141-Cable-Signal-Level/?l=en_US&fs=RelatedArticle#:~:text=Acceptable%20SNR%20Levels%20(dB)%3A,be%2033%20dB%20or%20greater.). Specifically:   Upstream Transmit Power Level Channel US Channel Type Symbol Rate Acceptable US Power Level   Single TDMA 1280 Ksym/sec +61 dBmV to 45 dBmV ATDMA 2560 Ksym/sec +58 dBmV to 45 dBmV 5120 Ksym/sec +57 dBmV to 45 dBmV     Two TDMA 1280 Ksym/sec +58 dBmV to 45 dBmV ATDMA 2560 Ksym/sec +55 dBmV to 45 dBmV 5120 Ksym/sec +54 dBmV to 45 dBmV   Three or more TDMA 1280 Ksym/sec +55 dBmV to 45 dBmV       ATDMA  2560 Ksym/sec +52 dBmV to 45 dBmV  5120 Ksym/sec +51 dBmV to 45 dBmV   Notice that my upstream power level never exceeds 42.77 dBmV but the acceptable level is 45 dBmV and up. Does any on the forum think this is proof of what the technician was saying? I'm not a network engineer so I don't know the accepted variance on the power level (e.g. is 42.77 "close enough" to 45 or is it out of range).   This *feels* right but I want to make sure it's actually right as I continue my conversation with Comcast. Not sure if they read these forums 😕 ... View more

Hi @jontalk,   It's the Xfinity Xfi gateway product that they provided with the subscription. I do agree that it's probably a network issue. After running PingPlotter for the whole day, I'm recording 2.6% packet loss with a period of 2 hours where it was averaging 4.7% packet loss. The latency on this averages 3s. Reading this answer (https://forums.xfinity.com/t5/Your-Home-Network/Packet-Loss-and-Latency-Spikes-Online-Chat-and-Games/m-p/3253512/highlight/true#M306495), I do wonder if forum users can echo the following solution:   * Problem: The issue was caused by severe damage to the node, box, on the side of my apartment. As my technician explained, "It looked like someone took an ice pick to the seal." * Solution: He swapped me to a new slot and replaced everything. In addition to this, he replaced the tip of every coaxial cable in my apartment with compression and removed any splitters, checked my frequency levels before and after the switch, swapped my modem to the best manufacturer in his opinion, made reccomendations, and explained everything along the way.    Thoughts? ... View more