3 Messages
OFDM 194 or node ingress
I have an Arris S34. This is not an in-home Wi-Fi issue. I already reseated the drop and isolated the modem.Event log: repeated T3 and T4 timeouts, loss of sync, Lost MDD, OFDMA channel 41 flapping profiles 10/11/12.Downstream OFDM 194 at 957 MHz is −14.4 dBmV, MER 30 dB, millions of uncorrectables. SC-QAM SNR dropped from ~38 dB to ~34 dB after reseating. Upstream TX is 44 dBmV, but that does not show CMTS ingress.
| Channel ID | Lock Status | Modulation | Frequency | Power | SNR/MER | Corrected | Uncorrectables |
| 20 | Locked | 256QAM | 471000000 Hz | -3.1 dBmV | 35.8 dB | 0 | 0 |
| 13 | Locked | 256QAM | 429000000 Hz | -3.9 dBmV | 35.6 dB | 0 | 0 |
| 14 | Locked | 256QAM | 435000000 Hz | -2.9 dBmV | 36.4 dB | 0 | 0 |
| 15 | Locked | 256QAM | 441000000 Hz | -2.7 dBmV | 36.4 dB | 0 | 0 |
| 16 | Locked | 256QAM | 447000000 Hz | -2.9 dBmV | 36.4 dB | 0 | 0 |
| 17 | Locked | 256QAM | 453000000 Hz | -2.9 dBmV | 35.8 dB | 0 | 0 |
| 18 | Locked | 256QAM | 459000000 Hz | -3.3 dBmV | 35.8 dB | 0 | 0 |
| 19 | Locked | 256QAM | 465000000 Hz | -3.3 dBmV | 35.8 dB | 0 | 0 |
| 21 | Locked | 256QAM | 477000000 Hz | -3.0 dBmV | 36.6 dB | 0 | 0 |
| 22 | Locked | 256QAM | 483000000 Hz | -2.8 dBmV | 36.4 dB | 0 | 0 |
| 23 | Locked | 256QAM | 489000000 Hz | -3.1 dBmV | 36.4 dB | 0 | 0 |
| 24 | Locked | 256QAM | 495000000 Hz | -2.9 dBmV | 36.4 dB | 0 | 0 |
| 25 | Locked | 256QAM | 501000000 Hz | -2.8 dBmV | 35.6 dB | 0 | 0 |
| 26 | Locked | 256QAM | 507000000 Hz | -3.4 dBmV | 36.4 dB | 0 | 0 |
| 27 | Locked | 256QAM | 513000000 Hz | -4.2 dBmV | 35.8 dB | 0 | 0 |
| 28 | Locked | 256QAM | 519000000 Hz | -4.8 dBmV | 35.6 dB | 0 | 0 |
| 29 | Locked | 256QAM | 525000000 Hz | -4.3 dBmV | 35.8 dB | 0 | 0 |
| 30 | Locked | 256QAM | 531000000 Hz | -3.9 dBmV | 36.4 dB | 0 | 0 |
| 31 | Locked | 256QAM | 537000000 Hz | -4.1 dBmV | 36.4 dB | 0 | 0 |
| 32 | Locked | 256QAM | 543000000 Hz | -4.3 dBmV | 36.4 dB | 0 | 0 |
| 33 | Locked | 256QAM | 549000000 Hz | -4.4 dBmV | 36.6 dB | 0 | 0 |
| 34 | Locked | 256QAM | 555000000 Hz | -4.7 dBmV | 36.4 dB | 0 | 0 |
| 35 | Locked | 256QAM | 561000000 Hz | -4.7 dBmV | 35.6 dB | 0 | 0 |
| 36 | Locked | 256QAM | 567000000 Hz | -5.2 dBmV | 35.8 dB | 0 | 0 |
| 37 | Locked | 256QAM | 573000000 Hz | -5.1 dBmV | 35.6 dB | 0 | 0 |
| 38 | Locked | 256QAM | 579000000 Hz | -5.1 dBmV | 36.6 dB | 0 | 0 |
| 39 | Locked | 256QAM | 585000000 Hz | -4.9 dBmV | 36.4 dB | 0 | 0 |
| 40 | Locked | 256QAM | 591000000 Hz | -5.3 dBmV | 35.8 dB | 0 | 0 |
| 41 | Locked | 256QAM | 597000000 Hz | -6.0 dBmV | 35.8 dB | 0 | 0 |
| 42 | Locked | 256QAM | 603000000 Hz | -5.8 dBmV | 34.9 dB | 0 | 0 |
| 43 | Locked | 256QAM | 609000000 Hz | -6.7 dBmV | 34.5 dB | 0 | 0 |
| 44 | Locked | 256QAM | 615000000 Hz | -6.7 dBmV | 34.5 dB | 0 | 0 |
| 193 | Locked | OFDM PLC | 690000000 Hz | -6.6 dBmV | 36.0 dB | 12220528 | 0 |
| 194 | Locked | OFDM PLC | 957000000 Hz | -14.4 dBmV | 33.0 dB | 1562839 | 12045082 |
| Upstream Bonded Channels | ||||||
|---|---|---|---|---|---|---|
| Channel ID | Lock Status | US Channel Type | Frequency | Width | Power | |
| 2 | Locked | SC-QAM | 22800000 Hz | 6400000 | 44.0 dBmV | |
| 4 | Locked | SC-QAM | 35600000 Hz | 6400000 | 44.0 dBmV | |
| 3 | Locked | SC-QAM | 29200000 Hz | 6400000 | 44.0 dBmV | |
| 1 | Locked | SC-QAM | 16400000 Hz | 6400000 | 44.0 dBmV | |
| 41 | Locked | OFDMA | 36200000 Hz | 44400000 | 44.0 dBmV | |


XfinityOrlandoM
Official Employee
•
3.8K Messages
8 hours ago
@teutonicc
Thanks for reaching out to us, we do apologize for any inconvenience you're having with your Internet services. Have you done any troubleshooting through our awesome Xfinity at with our chat assistant yet?
https://www.xfinity.com/support/articles/internet-connectivity-troubleshooting
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EG
Expert
•
121.5K Messages
7 hours ago
@teutonicc
It appears that there is a bit of a reverse tilt/slope condition present with the downstream channels. Google "cable tilt" for more info.
And we've seen this here before, where Comcast places an OFDM channel (194) too high in the frequency range near the end of the plant's bandwidth capability. Some of their cable plants and equipment still only extend out to 850 or 1000 MHz operation. At 957 MHz, it may be too close to the roll-off point of the plant's bandwidth capability, which explains the weak power level.
I would get a tech out to investigate, and they may need to escalate this to their plant/netwrk engineering department for correction. Good luck with it !
(edited)
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