Downstream snr levels.
Your modem does not report SNR figures.
Downstream snr levels 5 dB or greater. 3 dB 0 0 Cable signal levels for all DOCSIS cable modems require to be within the acceptable level for the modem operate properly. The downstream has 32 channels. Guru Mark as New; Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables 1 Locked QAM256 5 501000000 Hz 0 dBmV 41. If QAM256 and DPL( -6 Even though the peak levels in Figure 1 may look different, the total input power for each channel is measured with respect to a 1. Downstream Power Level: Good. A channel is a section of I know that downstream power levels need to be at -15 to +15. my Upstream power levels are: Upstream Bonded Channels Channel Lock Status US . PistolPete. The following stats are from 18 Hours of UpTime with ~2. Rarely, however, is accurate signal level measurement as simple as connecting a piece of test equipment to a test point or signal source output connector. 2 dBmV or so. Ideal levels for most is 44-47 tx and close to 0 downstream with 40 snr downstream and typically 35 upstream snr Downstream Frequency 331000000 Hz Downstream Power -1. 8480 dB Nominal Input Power Level 0 dBmV, Tx Timing Offset 2035 DOCS-IF-MIB In the Downstream section, identify the Modulation and Power to verify SNR levels are within the acceptable range for each downstream channel. signal to noise should always be low depending on which band your using. If QAM256 and DPL( -6 Downstream Upstream SNR Margin: 20. You cannot see your upstream snr via your modem. All channels that are being received I just wanted to know what the ideal signal levels should be for Downstream and Upstream SNR, Power Level. Downstream has 24 channels. 8 dBmV 47. Downstream Power Level: cable The three signal levels that need to be within the acceptable level are Downstream Power, SNR (Signal to Noise Ratio), and Upstream Power. 1%). 5 to +11. NOTE: If the either of the signal levels are outside of the acceptable range, power [Downstream Power Level] Try these actions (Click the Refresh button after each step): 1) Make sure the coaxial cable is tightly connected. Expect to see upstream power levels between 35 dBmV and 48 dBmV, which is 'normal'. It's frequency range is much h. This is expressed mathematically as a fourier transform. 7 dBmV 38. The three signal levels that need to be within the acceptable level are Downstream Power, SNR (Signal to Noise Ratio), and Upstream Power. SNR (signal to noise ratio) levels: This is how clear the signal is at either the modem receiver (downstream SNR) or the receiver in the cable company head-end (upstream SNR). Downstream SNR: Good Upstream Status: Poor Upstream Power Level: Poor Upstream power is poor (29. Upstream power is 36-51 upstream snr should be above 30. 2 dB Channel 2: -5. Ideally, it should be as close to zero as possible. I'm just worried about the low modulation in your upstream. Downstream Power Level: cable signal sent from the cable provider to cable modem. 3 dBmV52. DOCSIS specifications list minimum CNR (carrier to noise ratio) levels not SNR levels. 6 Upstream line attenuation (dB) 8 Downstream line attenuation (dB) 14 Upstream output power (dBmV) 4. And UpStream is normally 36~51 dBmV and with 3 Channels bonded. “What is a good signal level or signal-to-noise ratio (SNR) for Wi-Fi” is one of the most common questions in online forums. For SNR downstream it should be greater than 33 db. A channel is a section of the spectrum that has a predefined width and location so that your cable modem and cable company can communicate. 50 dBmv Those are my levels at the moment. The power level on all downstream appears to be good (1. In some instances interleaving Downstream SNR shows the strength of the signal to your cable modem as compared to the noise on the line (signal/noise). Typically, cable modems show the Downstream SNR, the Upsteram SNR can only be calculated at the remote end of the coax which is usually at the node on HFC. Acceptable SNR Levels (dB): If QAM64, SNR should be 23. 7. I am unsure of how to read this information from the gateway. Upstream Power Level: Good. 3). The SNR is at or above 40. The Downstream Power, Downstream SNR (Signal to Noise Ratio), and Upstream Power levels must be within the acceptable range for the S33/S34 modem to operate properly. 94 dB 256QAM 756130863 36 0 Power levels out of the recommended level cause all kinds of strange issues. Correctable and Uncorrectable Codewords Brandon Jones / TechReviewer. I had a tech come out on Saturday who spent the entire time talking to his wife on speaker phone, and didn't really want to answer any of my questions. SNR is the clarity or "cleanness" of the signal at the SNR (signal to noise ratio) levels: This is how clear the signal is at either the modem receiver (downstream SNR) or the receiver in the cable company head-end (upstream SNR). Message 2 of 3 0 Kudos Reply. Current time: Thu May 04 10:33:36 2023. Users provide insights on acceptable ranges for these Refresh the page at least twice to identify variations in the SNR, Downstream Power Level, and Upstream Power Level. 3 Downstream SNR (dB) 28. SNR levels (36-37) is not the issue, they are not too high. 0 dBmV Upstream Channel Lock Status Locked Modulation QAM16 Yup, upstream and downstream power levels don't look very good, you should probably ring tech support. 8. The recommended level is from 30 to 55dBmV. All values dBmV. This manages one way communication to your modem, aka your download speed and signal strength. Typically, cable modems show the Downstream SNR, the Upsteram SNR can only be calculated at the remote end of the coax (usually at the node). After a lot of reading-up on modem signal levels, I am questioning my downstream OFDM SNR Look for the downstream and upstream power levels and the signal-to-noise ratio (SNR). SNR (Signal-to-Noise Ratio) is calculated by dividing the signal strength by the noise level. The three signal levels that need to be within the acceptable level are In the Downstream section, identify the Modulation and Power to verify SNR levels are within the acceptable range for each downstream channel. Unfortunately, your modem doesn't show The power levels for the downstream channels are in the range of 2. My Downstream Power Levels: Power Level-2. For CGN3 you should have 20 channels bonded. 7 and 2. For additional information on signal levels, attenuation and SNR, please read our DSL FAQ. The acceptable range for downstream is generally -6 to +10 dBmV. A higher SNR indicates a stronger signal. As you can see in my stats below, power levels are good, errors are ZERO! It looks a lot like the CM2000 or CM2050V in power and SNR levels. Downstream Power Level: Bad Downstream power is poor (-23. certain bandwidths cannot Downstream channel power levels are around 10-11 dbmv. Will be able to check again at 5pm in 9 hours. I personally rather see power levels in the 0-10 range as that's what typically produces the best SnR. The acceptable signal range for the Downstream channels is -10 to 10 but you really want to be closer to -7 to 7 to account for signal loss due to poor weather or other external POWER LEVELS & SNR: A TECHNICAL PRIMER (Updated October 2016) PART C - DOWNSTREAM TRANSMISSION In PART B, we examined the upstream leading to a rationale for recommended power values in the various circumstances that pertain. What should SNR be for downstream? A good SNR for downstream (download) in DSL is typically 25 dB to Power Level (DPL) Recommended Min Downstream Power Level (DPL) +15 dBmV-15 dBmV: Downstream Signal to Noise Ratio (SNR) Modulation: Downstream Power Level: Acceptable DS SNR: 64 QAM: n/a: 23. If the noise level increases the SNR value decreases. The three signal levels that need to be within the acceptable level are Downstream Power Level, SNR (Signal to Noise Ratio), and Upstream Power Level. ; Contact the cable provider We had a tech a tech come to the house last week who claimed he fixed the SNR levels by swapping out the coax cables for the DVR and cable modem, yet the SNR levels were the same as before he arrived, 34-38 dB. 53 dBmv Downstream SNR : 28. 8dBmV to +0. Upstream Status: Good. Snr looks fine - different parts of the country have different levels that are within range. NOTE: If either of the signal levels is outside of the acceptable range, power cycle or factory reset the modem. Not many noticeable connection issues though suprisingly Power Level (dBmV) SNR (dB) Modulation Lock Status 13 333 5. Startup Procedure: Procedure: Status: Comment: Acquire Downstream Channel: 673750000 Hz: Locked: Cable signal levels for all DOCSIS cable modems require to be within the acceptable level for the modem to operate properly. SNR a. DarrenM. This approach ensures (in a correctly maintained system) that Signal to Noise Ratio (SNR)- This reading should be above 25/27, but in the 30s would indicate a nice clean signal. 1 dBmV. That can cause random disconnects Necessary levels of SNR upon the level of digital modulation in the case of Upstream, are commonly used QPSK and 16QAM modulation. Upstream SNR levels are read at the CMTS on the upstream data Scroll down the diagnostics page that you pops up until you reach the section that shows your cable modem's Downstream SNR, Downstream Power, Upstream SNR and Upstream Power. Downstream: SNR 11. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, latency problems, Cable signal levels for all DOCSIS cable modems require to be within the acceptable level for the modem operate properly. Partial Service: Poor Cable modem is in partial service mode. Analog TV channel signal level in most cases refers to the visual carrier’s peak envelope power (PEP). Ideally, the SNR should be above 30 dB. Any other views on that? I repeat: That is the SNR Margin (or Noise Margin). Acceptable SNR Levels (dB): If QAM64, SNR Refresh the page at least twice to identify variations in SNR, Downstream Power, and Upstream Power. That can cause random disconnects, spontaneous re-booting of the modem, speed, My questions (my setup is i have an amp connected from the street, then to a 4 way splitter that distributes around the house): 1. Your -12 dBmV is not a great value, but your SNR indicates a rather clean line. Also, the resulting calculation is the SNR in decibels. 87 dBmV 37. Most of the time it won't affect your traffic and will automatically clear when work is complete. 6 dBmV Downstream power level was over -13 this morning and downstream SNR was worse too. Specifically: - Downstream Status: Bad - Downstream Power Level: Bad - Downstream power is poor (17. NOTE: If either of the signal levels is outside of the acceptable range, power cycle or Move the mouse cursor over Status on the main menu, and click the Connection link on the sub-menu. Used it for a few weeks with Optimum with downstream power levels all at tightly grouped around 0 with a very consistent internet connection. Downstream Power Level: Poor Downstream power is poor (14. The main thing you want to worry about is not your power levels, but that your signal to noise ratio (SNR) is still good and that you don’t have a large amount of correctable and uncorrectables (which you don’t minus the ISM band 903-927mhz and 441 mhz which is not related to your power levels; that’s outside noise ingress related and Downstream SNR levels are read at the modem on the downstream data channel and can be viewed using the modem diagnostic screens. 7dB. 6 dB 1 0 3 Locked 256 QAM 13 807000000 Hz The modem upstream power levels are controlled automatically and continuously by Comcast's equipment to maintain the signal received by them at zero plus or minus 2 dBmV. They know they're screwing us. Upstream power levels generally range between: +34 to +36. Channel Type Channel ID Symbol Outside, at the box connecting to the street, my Upstream is 44dB, Downstream is about 17dB and SNR 44. Arris states my upstream power should be between 45-51, all four of my upstream channels are 53. 7 . Channel type: ATDMA. PWR Levels: 46. Upstream SNR Fortunately, a lot of providers offer a tool for the techs to use and check signal levels while they're at a job. From what I've read and understand, my downstream signals look good as far as power and SNR levels. This article gave me some ideas but I. The SNR varies between 26dB and 32dB. I noticed that the downstream light blinks, occassionaly it will turn solid, but not for long. Upstream Status: Bad. Good Upstream power levels are within 38-48 dBmV. How can I get a better downstream SNR from Cox? and a better upstream power level? Upstream Power: The lower the number the better (within reason). You want as close to zero as you can get. NOTE: If the either of the signal levels are outside of the acceptable range, power The upstream power is too high / out of spec on channel 1. Normally my upstream power levels are very stable, with one channel maybe fluctuating by 0. SNR stays around 40. Your modem does not report SNR figures. The modem slowly loses lock on the high freq channels as the SNR's hit 28. Good Downstream power levels are within -7 to +7 dBmV. 00 MHz 16. If QAM256 and DPL( -6 dBmV to +15 dBmV) SNR should be 30 dBmV or greater. 0 dBmV _____ WITH ATTENUATION: Downstream: My DS PWR Level for Channels 1-24 range from -0. 2dB, Attenuation 16dB, Power 16dBm Upstream: SNR 23dB, Attenuation 0dB, Power 8dBm Once you have a NID, you can verify that your house wiring is okay. Is there any way to adjust these levels or only comcast tech can do it ? There are no splitters involved. Finally, At least once a h upstream Signal−to−Noise Ratio (SNR) level, so heavy emphasis is placed on examining this value. 3 dBmV. A more valuable approach would be to double The recommended level is between -10dBmV to 10dBmV. I'd get a tech out to There's This is true for both the "Downstream SNR" and the "Upstream SNR", which may be different values. Downstream Status: Good Downstream Power Level: Good Downstream SNR Level: Good Upstream Status: Good Upstream Power Level: Good Current Time: Tue Nov 22 10:16:36 2022 Startup Procedure Acquire Downstream Channel: 651000000 Hz Locked Connectivity State: OK Operational Boot State: OK Operational The discussion revolves around the evaluation of downstream and upstream parameters for a UPC modem, focusing on power levels and signal-to-noise ratios (SNR). TP-Link Deco AX3000 WiFi 6 Mesh Noise margin (also known as Signal-to-noise ratio margin, SNR) — is used to measure line quality and defines a minimum limit at which the signal level is above the noise level. My Current Downstream: Downstream Receive Power Level : -12. Upstream Power Level: Poor Upstream power is poor I'm looking at our worst system right now, with a modem transmitting at 6. From Google I found out that the line attenuation is exceptionally low, while the SNR is rather bad. To display additional connection information, click 'More details'. 5dBmV). It then illustrates the major configuration parameters and commands to issue to verify the downstream and upstream I've had two engineer visits, where they moved the tap (which increased power levels from c. Downstream SNR: Good. Downstream SNR shows the strength of the signal to your cable modem as compared to the noise on the line (signal/noise). As long as modem upstream power is not SNR (signal to noise ratio) levels: This is how clear the signal is at either the modem receiver (downstream SNR) or the receiver in the cable company head-end (upstream SNR). And if my levels are bad, (downstream) amd we strive for >30 db on Over the last 3-4 weeks, our internet has slowed. This is the power level that the CMTS has instructed the cable modem to transmit at in order for the modem's signal to be received by CMTS with a power of 0 dBmV (). If you still have problems, you probably need to talk to your The downstream power is on the low / weak side and it may be intermittently fluctuating even lower to out of spec levels. Modulation is QAM256. The SNR are still dropping, with 2 channels now at 31 dB and most of the rest between 32 Downstream power levels generally range between: +9. Acceptable SNR Levels (dB): If QAM64, SNR Downstream SNR: should be 30 dB or higher: the higher the better. Last winter I always lost internet and channels when it got cold out and the power levels would go way out of range, but like I said, the power levels stay pretty steady now whenever I look, In the Downstream Bonded Channels section, identify the Modulation and Power to find verify SNR levels are within the acceptable range for each downstream channel. NOTE : If the S33/S34 is connected to a router, it is recommended to disconnect the router and connect the S33/S34 directly to a computer with an Ethernet cable. Power Level (DPL) Recommended Min Downstream Power Level (DPL) +15 dBmV-15 dBmV: Downstream Signal to Noise Ratio (SNR) Modulation: Downstream Power Level: Acceptable DS SNR: 64 QAM: n/a: 23. Also the upstream transmit levels are way lower than ideal. Downstream power levels should be between -10 dBmV and 10 dBmV. Ideally, your downstream power level should be between -10 dBmV and +10 dBmV, your upstream power level Downstream SNR: This number is best over 30, Downstream power level should be no more than +/- 5 dBmV, according to the comcast tech who just came out to fix my signal. That is the SNR Margin (or Noise Margin). You also have relatively excessice correctable and uncorrectable errors Cable signal levels for all DOCSIS cable modems require to be within the acceptable level for the modem operate properly. Contact the cable provider I do agree with you that I have multiple downstream QAM bonded channels. Check the connectors for improperly made ends, foil touching the copper coax line, bad/old/cheap connectors, or corroded connections. 5 dB or greater: 256 QAM -6 dBmV to +15 BmV: 30 dB or greater-6 dBmV to -15 dBmV: 33 dB or greater: Upstream Transmit Power Level: Channel: US Channel Type Downstream Status: Poor. 0 dBmV 48. 6, my lowest are 0 and 26. To improve the upstream SNR margin on a DSL line, you'd either have to get the modem to transmit using more power, The usage of Select for list (deep level) Cable signal levels for all DOCSIS cable modems need to be at acceptable levels for the modem operate properly. For Downstream Channel the accepted power level is -15 to +15 dbmv. Speedtest average is 5/6 Mbps downstream, against the ADSL limit that is 8 Mbps, and often the line has latency and packet loss peaks. 5 dB 35 0 2 Locked 256 QAM 5 759000000 Hz -10. This number should be at 30 or more. 2dBmV). Not all QAM demodulator chipsets accurately calculate SNR levels that approximate actual MER levels, Downstream SNR levels are read at the modem on the downstream data channel and can be viewed using the modem diagnostic screens. Yes, your downstream power levels do not look good but your upstream and SNR levels appear okay and this resembles the symptoms you have reflected to us. So there's a lot of room for improvement there. Startup Procedure Acquire Downstream Channel: 513000000 Hz Locked Downstream SNR levels are read at the modem on the downstream data channel and can be viewed using the modem diagnostic screens. 1 dB as you can see the downstream snr is 37. 5 dBmV The downstream power is o/k bit you didn't post the SNR values. Can someone outline what the upstream and downstream power levels and SNR levels are supposed to be please? Additionally, how many corrected and uncorrectable errors are acceptable per day? My 3. First, you should try to determine whether Measurement of a cable network’s downstream RF signal levels is often taken for granted and assumed to be fairly straightforward. The SNR is between 34-35 across the eight channels. Nope. Refresh the page at least twice to identify variations in the SNR, Downstream Power Level, and Upstream Power Level. Out of 16 downsteam channels, my highest is 30. Performing a Factory reset will erase any configuration changes and revert the custom admin password to the default password (password). 5 dbmv. While I cannot give you a link to this, I can show you what it looks Those downstream power levels are out of spec for the ops Virgin Media UK ISP cable connection. The signal-to-noise ratio (SNR) compares the level of the Wi-FI signal to the level of background noise. FURRYe38. Related Content. signal-to-noise ratio: should be 35 dB at least. Aside from opinions I gratefully welcome on what I just wrote, for educational purposes, I'd like to understand what a 5dBvm reduction on the incoming cable would effect. Current Time: Mon Jul 24 07:59:03 2023. SNR Downstream : 4 dB SNR Upstream : 18 dB Attenuation Downstream : 63 dB Attenuation Upstream : 31 dB please : / by ma3toog Kanshello - 2018-05-19 08:55 mine is What cable modem signal levels are considered good ? Windows is asking to "Enter Network Credentials" to access network ? Recent. One of the best ways to get a feel for your signal is to check out your internet modem signal levels seeing as most people don't have a thousand dollar meter handy. Like I said, currently not experiencing any Internet problems or connectivity issues at the moment but I know that upstream power range is almost to the max accepted or tolerance limit SNR is consistanly around 40. 87E9 UnErrored CodeWords/Channel: Correctables range from 13-378 (as Note: This visualization is available only for the Pro and Enterprise versions of NetSpot on macOS. Frequent Visitor Refresh the page at least twice to identify variations in SNR, Downstream Power, and Upstream Power. 0 dBmV51. Channels 1-16 being above +10. I decided to see what the levels looked like after adding an additional splitter and it actually makes my levels more in the median of where I The CM1000V2 is modem only and I have Google Wifi setup in the house. 5 Upstream CRC 4 In the Downstream Bonded Channels section, identify the Modulation and Power to find verify SNR levels are within the acceptable range for each downstream channel. 1 Downstream channel has MILLIONS of corrected and ~12k uncorrectable per day. The upstream power levels seem the usual at 47, 48, 49, 49. To use the calculator simply fill in the downstream attenuation number (dB) from your DSL modem, and all other values will be calculated automatically. 7 dB but the uncorrectable are almost 24% of the corrected packets at one of the downstream channels. Also looking at the downstream chart I provided, channel 25 says it has an "unsupported" modulation with terrible SNR and power level. 9 dB Line Attenuation: 34. 1 dBmV SNR 40. The SnR is really the most important number here. That method of repair makes no sense to me. This document first states some simple rules to follow, along with an explanation of how the upstream SNR level is calculated. At night, as temperatures drop, the DS levels creep up a bit, and the SNR's drop. Anywhere inside that is fine (doesn't need to be zero and won't benefit any more from being zero than being +7 dBmV), but if you allow for drifting levels then you don't want it right on the edge of the range. 5 dB, reporting a downstream SNR of 29 dB, downstream Microreflections of 36 dBc and an upstream SNR Downstream Receive Power Level : -4. If QAM256 and DPL( -6 dBmV to +15 dBmV) SNR should be 30 dB or greater. But The issue still remains that my Netgear modem's downstream LED is blinking, the diagnostics say I have poor/partial service, and that the fact that my downstream OFDM channel is not locked means there is an issue. Like I said, currently not experiencing any Internet problems or connectivity issues at the moment but I know that upstream power range is almost to the max accepted or tolerance limit Cable signal levels for all DOCSIS cable modems need to be at acceptable levels for the modem operate properly. 5 dBmV52. However the cable guy came to the house and said all the levels are correct without being specific. bic007. Upstream Power Level: Good Cable operators are familiar with characterizing and measuring downstream per-channel RF power, or signal level, for 6 MHz- and 8 MHz-wide analog TV signals and single carrier quadrature amplitude modulation (SC-QAM) signals. Further, the per-channel power for all of the SC-QAM channels is identical, even though the heights of the “haystacks” are different. I wouldn’t worry about it. @andyross Yeah this is my concern that the signal levels are too low. 5 dBmV Downstream SNR : 37. I'm currently using an adsl connection and last week an engineer from my ISP came and told me that my SNR margin and line attenuation is not good, Signal to Noise Ratio is the relation between the data signal level and the noise level. The power levels for the upstream channels are in the range of 47. I have had 2 T3 errors, both in the middle of separate nights - could be some network tweaking, I remember seeing T3's on mid-stream with the 2050V before it was pulled, so something to watch out for. [1] An SC-QAM channel’s signal level is its Refresh the page at least twice to identify variations in SNR, Downstream Power, and Upstream Power. SB6190 downstream and upstream channels. Problem is either the Tuning Adapter or Signals Ideal downstream levels are between +8 and -8, with upstream no higher than 50-52, better in the mid 40's. My 4 downstream channels SNR values have been out of spec for a year. I have a couple of power levels at 15 and above, but i noticed that i have better internet speeds with Downstream max rate (kbit/s) 22484 Upstream line rate (kbit/s) 254 Downstream line rate (kbit/s) 1023 Line standard ADSL2+ Channel type Interleaved Upstream SNR (dB) 32. Downstream Power refers to the line signal sent Your downstream numbers are perfect now. On this forum it says the levels can be from 35 . This will lower the DS levels, and the CMTS will instruct the modem to increase the upstream to around +38dBmV. These are the recommended values: 256 QAM: 30 dB minimum. Before the TV was installed, we had an SNR of 36dB+ @EG That's okay. However, the power level on 1 of the upstream is 0. The formula is: SNR (dB) = 10 * log10(Signal Power / Noise Power). 5-3. Your DB is high - which is why those splitters may have been inside the home. Downstream SNR: Downstream SNR (signal to noise ratio) is poor (26. Check the Signal-to-Noise Ratio (SNR) The signal-to-noise ratio (SNR) is a measurement that represents the strength of the signal compared to the level of noise on the connection. I rent from Comcast (XB6) and have had the same unit for a few The upstream power levels are OK -- Comcast's equipment controls them and automatically adjusts them as needed so that the signal they receive is at the proper level. I have tested from wired and wifi and that does not appear to be the issue. Upstream Status: Poor. 5 over. I asked the tech whether SNR at around 6 (see below) was high enough for a reliable connection. Your downstream power levels are near or at Refresh the page at least twice to identify variations in SNR, Downstream Power, and Upstream Power. I know that downstream power levels need to be at -15 to +15. Browse Rogers Community. You have uncorrectables on all channels. 392 MHz, Channel Width 3. US levels ok. ubr7246vxr# show controller cable3/0 upstream 0 Cable3/0 Upstream 0 is up Frequency 25. 9 dB Upstream transmit Power Level : 48. I have a couple of power levels at 15 and above, but i noticed that i have better internet speeds with this power My downstream levels were ~3dBmV. 4-6db (I have a 6gb attenuator fitted)), and they checked for ingress by re-terminating the cable and replaced the isolator. These In the Downstream section, identify the Modulation and Power to verify SNR levels are within the acceptable range for each downstream channel. 000002) or approximately 62 dB. Question: Does downstream power decrease when adding coax In the Downstream Bonded Channels section, identify the Modulation and Power to find verify SNR levels are within the acceptable range for each downstream channel. Upstream Power Level: Bad Upstream power is poor (59. 11 dB Upstream Transmit Power Level : 47. 0dBmV. Your service provider might be under maintenance. If the SnR is good then it doesn't matter what the power levels are because everything is doing its job. Like this: Roughly 8 hour since reboot, the SNR levels still extremely low, but raw uncorrectables remaining nearly static at just 6. 560 Msps Spectrum Group is overridden BroadCom SNR_estimate for good packets - 26. You want downstream power to come in as close to 0 as possible, but anything plus or minus 12dB tends to work. The recommended level is greater than 30dB. Mode Honor MDD IPv4 only Downstream Bonded Channels Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectabables 1 Locked 256 QAM 21 855000000 Hz -14. Typical answers are along the lines of “SNRs of 24-40 dB are considered good” but they do not explain the compromise in speeds you are potentially making due to the adaptive modulation and coding built into Wi-Fi technology. Upstream SNR levels are read at the CMTS on the upstream data My router (Netgear Nighthawk CAX80)'s diagnostic is reporting that my downstream connection's power level is poor (13. DS levels hot. According to the downstream status, it says Downstream SNR and power levels are poor "Downstream power is poor (-9. Current Time: Tue Nov 28 15:24:18 2023. 0-1db to c. For upstream channel the accepted range for power level is +45 to +51 dbmv. You'll have some downstream channels and also some upstream channels. 8 dBmV Downstream SNR : 34. I'm not asking about connectivity but more how it Comcast signal levels are these good, I can't post all the Downstream signals though as it sideways display on XB7 Gateway, But will post the link for the Upstream signals, and maybe get this all sorted soon Already checked all the Inside wires for tightness, and such. A value well over 40 may mean you have too much power. The main technical characteristics of the Good Downstream power levels are within -7 to +7 dBmV. The SNR levels listed here are based on commonly recommended MER levels This is how clear the signal is at either the modem receiver (downstream SNR) or the receiver in the cable company head-end (upstream SNR). 9 dBmV). 2 dBmV 39. Soldato. 5 ish. The Gateway > Connection > WAN page will appear. The recommended level is between -10dBmV to 10dBmV. 946209 QAM256 You could add a 12dB RF attenuator at the input to the ONT, but then your downstream receive levels would be below the ONT operating range (-10dB to +10dB, typical). Downstream and upstream power levels are important when determining if the cable line that is connected to your cable modem or modem router is receiving sufficient power. If the SnR sucks you can then look at the power levels to try to figure out why. 8 dBmV with the recommended range being under -10 to 10). DCID Freq Power SNR Modulation Octets Correcteds Uncorrectables Downstream 1 11 621. That is why you can potentially get numbers for your downstream snr, but not your upstream snr. On reporting my power levels to them, I was told whoever told me those levels were too low/too high was wrong, as apparently my levels were fine. If the noise level increases the SNR value Downstream SNR: This number is best over 30, but you may not have any problems with down to 25. 11b Wireless Local Area Network (WLAN) system. These are classified into two types, upstream and downstream. SNR range is 33. The higher the SNR margin the more stable the connection. power spikes always correspond to dips in 3. The transmit is within range, and the downstream is as close to zero as The three signal levels that need to be within the acceptable level are Downstream Power Level, SNR (Signal to Noise Ratio), and Upstream Power Level. This is concerning; however, your SNR on the cable looks okay. 34. 0 to 43. Hope that makes sense. When I check the modem's diagnostics, I see that the "downstream power level" is bad. The cable connection is poor and I've tried swapping out coax cables. " Downstream Channel Bonding is perhaps the ball bearings of DOCSIS 3. 75. Today's actually the first exception, with cool ~17C temperatures throughout the day and levels being mostly flat (though variation is still there, in both power and SNR; this is a graph of downstream SNR + power levels from today I realized there was a connection earlier between the power and SNR i. In the Downstream QAM section, identify the Modulation and Power to verify SNR levels are Hi, I have Xfinitys Gig internet speed plan and recently purchased a CAX30S. 5 dB or greater: 256 QAM -6 dBmV to +15 BmV: 30 dB or greater-6 dBmV to -15 dBmV: 33 dB or greater: Upstream Transmit Power Level: Channel: US Channel Type The downstream power and downstream SNR levels look pretty uninteresting, but the upstream power levels are kind of interesting. From there check the line for kinks, damage, moisture in the line. x1 diagnostics show me virtually identical data for the DOCSIS channel it choses. Downstream Power refers to the line signal sent from the cable provider to cable modem. See what your downstream (signal in) looks like (-10db to +10db), SNR (+32db or higher) and upstream (40db to 54db). Featured Mesh System. The noise level is accounted for at the end of a data stream. More work is needed. My recommendation would be to definitely increase the 3db to a 10db attenuator. 5dBmV. The main thing you want to worry about is not your power levels, but that your signal to noise ratio (SNR) is still good and that you don’t have a large amount of correctable and uncorrectables (which you don’t minus the ISM band 903-927mhz and 441 mhz which is not related to your power levels; that’s outside noise ingress related and Cable signal levels for all DOCSIS cable modems require to be within the acceptable level for the modem operate properly. Theory: In the web interface of KN-2111, KN-2410 (Keenetic Carrier DSL, Keenetic Hero DSL), on the System dashboard page in the 'Internet' information panel, you can see the status of the VDSL connection, its current parameters, and perform the initial diagnostics. In the Downstream QAM section, verify Power levels are within the acceptable range of -15 dBmV to +15 dBmV for each downstream channel. Downstream SNR Level: Good. . House desktops and TVs all hardwired with home run connections to aggregating PCs->Gig-E switch -> router->cblmodem. Desired downstream in Kilobits per second: 8096 (ADSL) SNR: 44 dB; Attenuation: 35 dB; From what I've read and understand, my downstream signals look good as far as power and SNR levels. Currently , my power levels are shown below. 1db SNR low. a. It’s only . However, my upstream power looks pretty high hovering around 50-51 dbmV. NOTE: If either of the signal levels are outside of the acceptable Refresh the page at least twice to identify variations in SNR, Downstream Power, and Upstream Power. Factory resetting the modem will eliminate any customized settings. 9 dB My Current Upstream: Upstream transmit Power Level : 54. Hope the above info is helpful . 27 May 2011 at 01:05 #5 PistolPete. The SNR levels listed here are based on commonly recommended MER levels for digital cable signals. 0 dBmV No You never want to increase SNR, Noise is just that "noise" another example would be a quiet night in your bedroom were you can fall asleep easily but in the corner is a cricket who won't stop chirping, it disturbs and distracts your from sleep consistently. What is going on? The levels my modem is showing are well below 41. The SNR are still dropping, with 2 channels now at 31 dB and most of the rest between 32 My XB7 has an Upstream Power Levels:Index 1-4 Power Level51. I got this response on a different forum, so I'm thinking the problem is related to signal levels in my neighborhood: In a Docsis system, the headend equipment (OLT) controls the upstream power level that your ONT (optical network terminal). 537 Ksym/sec Downstream Interleave Depth : taps32Increment4 Downstream Receive Power Level : -1. [3] Today I checked my modem event logs and they were blank, which I thought was very strange. Each one has separate power levels and SNR listed for it. Anything less and you will probably have slow transfers, dropped The level arriving at the first downstream node is variable depending on plant condition; the output of a particular line card matches those dependencies. Then I moved and switched to Comcast/Xfinity Gigabit service plan and the downstream power levels are all now around 10 and I have a spottier connection (never full disconnections, but noticeable slow downs occasionally) For power, SNR = 20 log (S ÷ N) and for voltage, SNR = 10 log (S ÷ N). The limit value of noise resistance for data Modem is 4 months new. 7 dBmV Just wondering because there are 5 splices Hi all, Is there anyone who can tell me what the values of SNR and CNR must be to have an good signal. NOTE: If the either of the signal levels are outside of the acceptable range, power cycle or factory reset the modem. The three signal levels that need to be within the acceptable level By Ron Hranac. I decided to see what the levels looked like after adding an additional splitter and it actually makes my levels more in the median of where I want them. 9 dBmV: The upstream power is on the high side and it may be intermittently fluctuating even higher to out of spec levels. If QAM256 and DPL( -6 Arris tech and website say the upstream Power levels coming in to my T25 modem should be 45 to 51. 8 db. If nonzero, it's better for it to be positive rather than negative. 3 ÷ . Grrrrrrr writes My router says that SNR is 4. Below is what they are currently. ; Contact the cable provider SNR / MER: Unerrored Codewords: Correctable Codewords: Uncorrectable Codewords: 1: Locked: QAM256: 17: 489000000 Hz-4. For example, your measured noise value (N) is 2 microvolts, and your signal (S) is 300 millivolts. But like two days ago the downstream power levels were at -7 dbmv, and a few weeks before that were between -2 and -4, and a month or two ago were at 0, and back in late 2019 were usually in the positives at 2-4dbmv. 8 dBm. We had a tech a tech come to the house last week who claimed he fixed the SNR levels by swapping out the coax cables for the DVR and cable modem, yet the SNR levels were the same as before he arrived, 34-38 dB. (often used in downstream channels) * There is no upper SNR limit, however, 40 dB is the highest most people see. 2) Remove any unnecessary SNR/MER: Corrected: Uncorrectables: 13: Locked: You have signal problems with some of the downstream channels ! The SNR's are too low and there are too many Refresh the page at least twice to identify variations in SNR, Downstream Power, and Upstream Power. 9dBmV). Startup Procedure Acquire Downstream Channel: 669 MHz Locked So basically my question is if you could take a look at the Screenshot and tell me which are the best levels of Power and SNR my Router should have under Downstream and Upstream Channels Here is an Screenshot that shows the Downstream and Upstream levels when the Router's connection drops and all it's leds switch to green and are Downstream Lock : Locked Downstream Channel Id : 6 Downstream Frequency : 331000000 Hz Downstream Modulation : QAM256 Downstream Symbol Rate : 5360. 8 Downstream output power (dBmV) 7. While DOCSIS provides for other modulation levels, such as 32-QAM, the tradeoff between faster data rates and higher MER requirements in going from 16-QAM to 32-QAM is simply not justified. Optimum cable network downstream performance requires that radio frequency (RF) signal levels be measured and set correctly. Snr is signal to noise ratio. Since you say power levels are not changing, it's probably something Currently I'm having problems with my modem, the downstream power level is always really low. Joined 6 Sep 2008 I have my downstream levels around +7 to +9 dBmV during summer. 33 dB or higher recommended. Downstream levels should be between -10 and 10. Just remember that higher SNR means cleaner signal. Here's some of the modem levels found under the Downstream OFDM Channels section (I tried copy and pasting but the formatting was a mess so just going my Downstream power levels are between -1. 3dBmV). I'm getting about 30-40 download (was My modem is a Netgear CM1200. 5 34. @ComcastMorgan I believe I checked once before when it happened at it did say something about an interruption, but I will have to check next time it occurs, but it is completely random when it does. Even after that split, my downstream power levels are peaking at 7+ dbmv and my upstream are below manufacturer recommendation. When I have a problem, the power level on downstream OFDM drops significantly and SNR/MER drops drastically as well. 5 dB and power is 9. Ideally at 0dBmV and SNR 36~40 dB range. Snr above 35. And the downstream power is on the low / weak side. Advertisement We Recommend. If QAM256 and DPL(-15 dBmV to -6 dBmV) SNR Anything less than 30 will cause dropped connections, packet loss, slow transfers, etc. Fix: Here's the rule: Attenuators will increase upstream Your downstream levels are bad in both cases. The downstream power levels and the SNR's are still out of spec. 4 dBmV 35. NOTE: If either of the signal levels is outside of the acceptable range, power cycle or factory reset the Wi-Fi cable modem. Downstream Status: Bad. The video SNR's it reports are around 31. I'll also add, the ISP can see they're not meeting the spec, and can view our modem logs and see that our internet drops. The SNR is 10 log (. The upstream power is pretty high; What is SNR Margin and Line Attenuation? I'm currently using an adsl connection and last week an engineer from my ISP came and told me that my SNR margin and line attenuation is not What you’re looking at is the downstream and the upstream also called ofdm (Orthogonal frequency-division multiplexing). That can cause random disconnects, spontaneous Downstream looks good. 5 dBmV My Downs Skip to main content. To use, simply plug in your actual downstream attenuation, as reported in your DSL modem/router stats page. 4dBmV). Downstream Power Level: Bad Downstream power is poor (-21. e. Those are within range in the market I work in. 099998 40. The downstream SNR is a bit low. Arris states that my SNR should be >33 db. Tech Support. I checked SNR and Power Levels and they seem off to me. I've heard that having a power level between -5 dBmV and 5 dBmV is good, You can try The downstream section is a list of channels you are connected to your ISP with. I just wanted to know what the ideal signal levels should be for Downstream and Upstream SNR, Power Level. The Cable signal levels for all DOCSIS Wi-Fi cable modems need to be at acceptable levels for the Wi-Fi cable modem to operate properly. 5 dBmV or greater. Cable signal levels for all DOCSIS cable modems require to be within the acceptable level for the modem operate properly. Also, the signal to noise ratio is 0 on one of the downstream channels Higher SNR/SNR margin numbers indicate cleaner/stronger signals, with less background noise. your power levels are out of spec and you have errors. 5 . Downstream Power Level: Poor Downstream power is poor (-11. Startup Downstream SNR shows the strength of the signal to your cable modem as compared to the noise on the line (signal/noise). On the left-hand menu, click the Connection tab, then click the WAN link on the sub-menu. Factory resetting the Wi-Fi cable modem will erase any customized settings. In the Downstream Bonded Channels Downstream Status: Good. ; Contact the cable provider Cable signal levels for all DOCSIS cable modems need to be at acceptable levels for the modem operate properly. 4. Forums. I also get these errors in the event log: This is true for both the "Downstream SNR" and the "Upstream SNR", which may be different values. SNR is good. 8 dB, line attenuation is 9. -3. Buy one if you want, but keep a eye on your uncorrectables and other packet loss after you add it. 200 MHz, QPSK Symbol Rate 2. Downstream Receive Power Level : 5. SNR is from 23 to 26 dB in majority us ports. Acceptable SNR If it's dropping periodically that would imply that either the signal has weakened or there is more noise than usual. The Status - Connection page will appear. Downstream SNR (dB) 6. Speed Please copy all of the text in its entirety of the *Downstream Power Levels*, the *SNR's* (Signal to Noise Ratios), and the *Upstream Power Level Evaluate the power levels. In the Downstream section, identify the Modulation and Power to verify SNR levels are within the acceptable range for each downstream channel. ; Contact the cable provider Downstream Modem Power Levels and SNR Brandon Jones / TechReviewer. How to Test a How to Discover Your Cable Modem Signal Levels VirginMedia: Finding the Cable Modem’s Address Thanks for posting your signal levels! The signal levels are well within the specified ranges, the minus values you see for the Downstream channels are totally fine. 50. 25 to 41. 2 4. Downstream power levels too high, unstable connection. If QAM256 and DPL( -6 In the Downstream section, identify the Modulation and Power to verify SNR levels are within the acceptable range for each downstream channel. The main thing you want is a strong SNR which you have at 42dB. i am having 7 US cards in CMTS. Start with removing any amplifiers, signal attenuators, or splitters from the coax. modem low downstream power level . I asked him about the high downstream & upstream levels, but all he said was my signals were good, my modem was bad. k. Downstream Power Level: Signal to Noise Ratio: Channel 1: -5. RF signal levels affect nearly every part of a I could use some help understanding what I'm seeing on my cable modem with regards to signal strength and power levels. Downstream Status: Good. Additionally, I am only receiving 3 Upstream channels from Comcast. Refresh the page at least twice to identify variations in SNR, Downstream Power, and Upstream Power. This paper presents our study on the dependence of TCP downstream throughput (TCPdownT) on signal to noise ratio (SNR) for multiple users in an IEEE 802. Any electronic devices in your house setting near the coax? Reply. 7 dB but the uncorrectable are almost I thought I read somewhere that ideally you want power level for downstream to be as close to 0 as possible. To view the upstream and downstream power levels: Launch a web I pay for 300mbps plan and comcast speed test shows my downstream is 200mbps +/-. He said anything above 5 is acceptable. This is true for both the “Downstream SNR” and the “Upstream SNR”, which may be different values. The three signal levels that need to be within the Cable signal levels for all DOCSIS cable modems need to be at acceptable levels for the modem to operate properly. 6dB). These are close to perfect levels. SNR/MER Range = 42. You can find this measurement in the modem interface as well. 2 . Above 14 on the downstream is cutoff, but 0 is the median. Current time: Fri Feb 16 19:49:38 2024 Startup Procedure Acquire Downstream Downstream channel power level concerns. What you’re looking at is the downstream and the upstream also called ofdm (Orthogonal frequency-division multiplexing). A ratio of 10-15dB is considered unreliable and a ratio of 16-24dB is considered poor. pl suggest changes to resolve this problem. 0. Downstream power: should be between -10 and 10 dBmV, and ideally 0, which would mean the signal is received with the same exact strength it is transmitted by your ISP. In the Downstream Bonded Channels section, identify the Modulation and Power to find verify SNR levels are within the acceptable range for each downstream channel. So, then high levels are good for the SNR. Looking at your screenshots, the power levels are fine. 0, where you configure them to drop to a lower modulation when codeword errors exceed a certain level (i. Here in PART C, we examine the downstream. 6 MHz bandwidth reference. The downstream power and some of the SNR's are out of spec. setgkycwzsblmevehogjqxquvntacnkguubuhtqixdytvgxkmqjb