This document contains very detail information on how to use the CNR debugs. If BPI is configured then you'll see status online(pk) and then followed shortly by online(pt). Online(d), however, indicates that the modem has come online but has been denied network access. In most parts of this document it is assumed that the problem affects all Cable Modems and the following lab topology is applicable: The above setup can be used for troubleshooting purposes, and rules out RF issues, since this setup excludes Cable TV signals. This can be measured by the spectrum analyzer. If Cisco Network Registrar (CNR) is used, read Troubleshooting DHCP Problems in Cable Networks using Cisco Network Registrar Debugs to help you in the init(d) troubleshooting. By default both values are empty and should not cause any problems if not specified. At this stage, the CM begins a ranging process to calculate the necessary transmit power level to reach the CMTS at its desired input power level. I currently have Spectrum. Welcome to the community and thanks for posting. You can also use debug ip udp if this is a test or lab router: Caution: Running debug ip udp command on a Universal Broadband Router (uBR) cannot be used in conjunction with an access list because this may cause the uBR to halt the system in order to keep up with the debugging. Once a usable UCD is found the modem will begin to listen to MAP (Bandwidth Allocation Map) messages which contain the upstream bandwidth allocation map of time. Item Status CommentsAcquired Downstream Channel (Hz)298750000LockedRanged Upstream Channel (Hz)39400000LockedProvisioning StateOnline, Downstream bonded channelsChannel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID1 298750000 -2.5 40 256 qam 212 138750000 -2.7 40 256 qam 13 146750000 -2.7 40 256 qam 24 154750000 -2.7 40 256 qam 35 162750000 -2.7 40 256 qam 46 170750000 -2.5 38 256 qam 57 178750000 -2.4 38 256 qam 68 186750000 -2.2 38 256 qam 79 194750000 -2 40 256 qam 810 202750000 -2.2 40 256 qam 911 210750000 -2.2 40 256 qam 1012 218750000 -2.2 40 256 qam 1113 226750000 -2.2 40 256 qam 1214 234750000 -2.2 40 256 qam 1315 242750000 -2.2 40 256 qam 1416 250750000 -2.4 40 256 qam 1517 258750000 -2.5 40 256 qam 1618 266750000 -2.5 40 256 qam 1719 274750000 -2.5 40 256 qam 1820 282750000 -2.5 40 256 qam 1921 290750000 -2.5 40 256 qam 2022 306750000 -2.4 40 256 qam 2223 314750000 -2.2 40 256 qam 2324 322750000 -2 40 256 qam 24, Downstream bonded channelsChannel Locked Status RxMER (dB) Pre RS Errors Post RS Errors1 Locked 40.9 18 02 Locked 40.9 0 03 Locked 40.3 6 04 Locked 40.3 4 05 Locked 40.3 5 06 Locked 38.9 21 07 Locked 38.9 18 08 Locked 38.9 5 09 Locked 40.3 5 010 Locked 40.9 18 011 Locked 40.3 5 012 Locked 40.9 5 013 Locked 40.9 5 014 Locked 40.9 4 015 Locked 40.3 5 016 Locked 40.3 6 017 Locked 40.3 6 018 Locked 40.3 4 019 Locked 40.3 5 020 Locked 40.9 3 021 Locked 40.3 6 022 Locked 40.9 4 023 Locked 40.3 5 024 Locked 40.3 14 0, Upstream bonded channelsChannel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID1 39400000 3.75 5120 64 qam 122 32600139 3.75 5120 32 qam 133 46199976 3.75 5120 64 qam 114 53699961 3.75 5120 64 qam 10, Upstream bonded channelsChannel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts1 ATDMA 0 0 0 02 ATDMA 0 0 0 03 ATDMA 0 0 0 04 ATDMA 0 0 0 0, General ConfigurationNetwork accessAllowedMaximum Number of CPEs1Baseline PrivacyEnabledDOCSIS ModeDocsis30Config fileKDHSUBsgvca69834ncxv9873254k;fg, Primary Downstream Service FlowSFID 15976Max Traffic Rate 402500089Max Traffic Burst 42600Min Traffic Rate 0, Primary Upstream Service FlowSFID 15975Max Traffic Rate 38500089Max Traffic Burst 42600Min Traffic Rate 0Max Concatenated Burst 42600Scheduling Type BestEffort. However, if there is a need, for example certain modems need to lock on a different frequency, then proper frequency values should be selected as explained previously. Have called the customer center multiple times and even there were couple of engineer visits but to no vain. This is what I've tried: 1. If a T3 timeout occurs, the retry count increments. Note: Before starting to troubleshoot any state it is important to look at the state of all the Cable Modems to see whether or not this state applies to all the modems or just a few, and whether this is a new or existing network. Consequently I am unable to identify your account. Note: Refer to Understand How Basic Initialization Works for a Cable Modem Initialization Flowchart and a quick overview. Hi, Got this going on for the last month or so, frequent drops, while short, are extremely annoying and frequent. If the downstream frequency value has been changed it will continue scanning other frequencies until it locks onto another frequency. Tried all the troubleshooting I could find here, as well as from 3rd party sources, but no dice, it comes back and goes away randomly Here are the logs which I … In some cases you may have a good Signal to Noise Ratio (SNR) of say 34dB but still have noise present such as impulse noise. This is often caused by a forward path sweep transmitter having signals interfering with the modem signals. If a DHCP server responds to the DISCOVER with an OFFER, the modem may choose to send a REQUEST for the offered configuration. ‎04-12-2018 It may be worth you creating a Broadband Quality Monitor to see how your connection is performing. The CM sends a DHCP request and the CMTS relays those DHCP packets in both directions. However, the upconverter GI C6U or C8U uses 1.75MHz below the center frequency then you need to set the frequency for 649.25 MHz for Channel 100-100. Sometimes the internet will drop for a couple of seconds and sometimes as long as 2 minutes. I'm sorry to read you are experiencing intermittent connection. If you see an ! For more information see Baseline Privacy Interface Specification . ‎12-12-2018 By clicking OK, you consent to the use of cookies. As shown above Cable Modem with SID 3 has failed registration due to bad class of service (COS) or reject(c). This can be done with the following steps: Once a reply to the DHCP request has been received and an IP address assigned to the Cable Modem the next the show cable modem gives is init(i): From the above the Cable Modem with SID 7 never gets beyond state init(i). This SID will be used to identify unicast transmission regions in the MAP for unicast ranging. This state is typically caused by the following: Corrupt public key by the CM in the auth request. Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=6c:ca:08:70:e8:99;CMTS-MAC=00:01:5c:74:8e:73;CM-QOS=1.1;CM-VER=3.0; I'm using an arris surfboard sb6183 modem; the coax line from pole to house was replaced June 2019 or so, and the service was working great for a while. It may help to try the following so we can rule some things out: Pop the hub into Modem Mode with the computer in Safe Mode with Networking at different times of the day. The output below shows this situation. Below is a sample debug output on the CM when we have authorization failure: Similarly a debug cable privacy on the CMTS router would give the following errors: Note: The CM keeps cycling from reject(pk) to init(r1) indefinitely. 17:21 Note: The uBR7100 has an integrated upconverter so an external upconverter is not required. From the output display of show cable modem command above we have four modems in the offline state. It directly controls the length of time to recover the network. 14:06. There could be a number a reasons for a Cable Modem not getting further than init(i). Here is a debug output display taken on the CM side with the debug cable-modem mac log verbose showing only the registration part: If there is a problem with BPI in general you'll see reject(pk) meaning we could not get through the key authentication stage. The show controllers cable command is a good place to start. Since the Cable Modem has reached as far as init(i) we know that it has gone as far as obtaining an IP address. Make sure you can ping the time-server to rule out IP connectivity issues and also make sure the time-server is available. No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; DHCP RENEW sent - No response for IPv4;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; DHCP REBIND WARNING - Field invalid in response;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0. Usually there is no need to specify a frequency value under this option. Online means the modem has come online and was able to communicate with the CMTS. This can be configured using cable upstream range-backoff command. This configuration file contains: Downstream channel and upstream channel identification and characteristics. Your last log in was from an IP address which doesn't relate to a Virgin Media account, and your sign-up email address is also non-Virgin Media. This can be clearly shown in the output display of the output of debug cable-modem mac log verbose at the Cable Modem below: Similarly, TFTP server issues would give similar errors resulting in the CM resetting and cycling through the same process indefinitely: A way to test the TFTP server is by trying to download a small file (like the DOCSIS config file) into the flash card of the CMTS. Note: For correct BPI operation ensure that the CMTS and CM are both running a BPI enabled image, which is signified by the symbol K1 in the image name. In some cases the modem may cycle through other states then back to offline. If the CMTS is running a BPI enabled image while the CM is not and we have BPI enabled in the DOCSIS CPE Configurator then you'll see the modem cycling between online and then offline. The DHCP server can respond with an acknowledged (ACK) or not acknowledged (NAK). The CM MIC is a hashed calculation over the configuration file settings which provides a method for the modem to be sure the configuration file wasn't tampered with in transit. I have taken a look and things seem to be ok from this side. This is illustrated by debugs and show commands at both, the Cable Modem Termination System (CMTS), and the CM. If packets are seen to be transmitted onto the DHCP server subnet, it would be a good idea to double check the modem debug messages to see if there are parameter request or assignment errors. Once locked, it will save the new value for next time. The time is used for syslog and event log timestamps. Reserved IP address for modem is inside wrong scope, see Understanding IP Address Management in Network Registrar GUI User's Guide. This can only be detected by a spectrum analyzer operating in the zero span mode. This will be due to clipping of the signal. A more accurate state can be derived by displaying the output of show controller cable-modem 0 mac state. on This is likely to be either a headend misconfiguration or a less than DOCSIS compliant modem. Below we have Cable Modems with SID 1 and 2 in init(t). No ranging response received - T3 timeout. Tried all the troubleshooting I could find here, as well as from 3rd party sources, but no dice, it comes back and goes away randomly Here are the logs which I … This document is not restricted to specific software and hardware versions. It would also be advisable to double-check the DHCP server configuration and the DHCP logs. New around here? The main configuration and administration interface to the cable modem is the configuration file downloaded from the provisioning server. Below is cut down output display of show controllers cable-modem 0 as taken from the Cable Modem (Kuffing) end: From the above we can see that the Signal to Noise ratio estimate is 16.6 dB. (Cat 5e or above). This is covered in the reject(pk) and reject (pt) section. I will pop you a PM (Purple Envelope, top right hand corner) so we can investigate further. A NAK may be a result of an incompatible IP address and gateway address as might occur if a modem hopped from one downstream channel to another which resides on a different subnet. Note: The above access list is configured globally and has no effect on the IP operation. I've notice a few of the same errors on this post so I"m looking for some help from the team if possible please. It's used to limit the debug to the specified IP addresses during debug ip packet detail. Sorry to Hijack on this thread but I'm not sure where else to post in order to get a response. We would like to show you a description here but the site won’t allow us. Frequently, errors at the DHCP state manifest themselves as timeouts rather than NAKs. The following list gives the most common reasons for a modem not able to achieve quadrature amplitude modulation(QAM) lock: The Cable Modem is not connected to the network or it is not turned on, Incorrect Frequency Specified in the DOCSIS file, Absence of downstream digital QAM modulated signal, Incorrect frequency specified in cable modem change-frequency on the CMTS router. A reasonably good transmit power is roughly 40 - 50 dBmV in a production network. The RNG-RSP messages contain power and timing offset corrections the modem must make. The document highlights the most commonly used Cisco IOS® software troubleshooting commands to verify what state the CMs are in, and the reasons that can cause the modems to arrive at that state. 21:25. T4 (Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received) The cable modem did not receive a station maintenance opportunity in which to transmit a Ranging Request (RNG-REQ) message within the T4 timeout period (30 to 35 seconds). The time to wait for a station maintenance interval to perform station maintenance ranging. In this case, all the modems may lose sync, and debugging will be useless. Notice that cable modems with SID 97, 99, and 100 use port upstream 0 while the rest of the cable modems use telco return for the upstream path. When the modem seeks renewal of the lease, the IP address and the gateway address of the DHCP REQUEST message will be different network numbers and the DHCP server will refuse the REQUEST with a NAK. Presence of cable privacy authenticate-modem configuration command on the CMTS router but no Radius server present. This website uses cookies. If the retry count is less than the maximum number of retries, the modem transmits another RNG-REQ at a higher power level. Fireware Verison: V1.01.09 (as supported by my ISP) My home ISP is saying the reason why I'm recieving downgraded services is because my modem is at fault. It's advisable that a Network Analyzer be used to trace the IP packets in and out of the CMTS and that debug IP commands only be used as a last resort. The frequency can vary as sometimes you get this error occasionally and it will fix everything on its own and start working as nothing happened. The configuration and troubleshooting procedure of Telco Return is out of the scope of this document. Below is a an output display of show cable modem showing a modem with SID 7 in init(d), which indicates that the DHCP request was received from the Cable Modem: Note: The Cable Modem cycles through init(r1) to init(d) indefinitely. The best value for insertion-interval is automatic. Note: You may not always see init(o), instead you might see init(i) and then cycling through from init(r1) to init(i). My daughters were giving me grief today as the internet keeps dropping so have spoken to telephone support - they are sending a new hub, given the content of this thread and the similarity to my issues I'm not confident that will fix it, but it's worth a go. The CM sends a ranging request (RNG-REQ) message to the CMTS and waits for a ranging response (RNG-RSP) message or a T3 timer expiration. Our modem is dropping connection, the logs are below. Roughly 20 - 30 dB of attenuation is a good place to start. 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 recommended value is 1600 or 1800 bytes. After initial ranging init(r1) the modem proceeds onto init(r2) which is where the modem must configure the transmit timing offset and power level to ensure that transmissions from the modem are received at the correct time and are at an acceptable input power level at the CMTS receiver. on After a downstream channel has been acquired, the next task is to locate a suitable upstream channel. Refer to sample debug cable privacy for proper sequence of events. Another common mistake is to specify an incorrect frequency value in the Downstream Frequency field under the Radio Frequency Info in the DOCSIS CPE Configurator. Refer to RF Specifications for Data Over Cable Service Interface Specification (DOCSIS) Downstream and Upstream specifications, and also About Verifying the Downstream Signal. From checking your line, everything has come back as fine. This shared secret is known by the CMTS and ensures that only authorized modems will be allowed to register with the CMTS. The above output shows that Cable Modem with SID 1 is in reject(m) state. If the modem doesn't receive a response back in the specified time frame, it logs the event as a critical T3 timeout. To know how to create a DOCSIS Configuration file that denies PCs connected to CM. Check Ethernet cable. However, after Cisco IOS Software Release version 12.1(1) TOD is not required but the Cable Modem still needs to get the timing offset, as shown in the following debugs: In the debugs below we have no time-server specified but we have a timing offset configured in the DHCP server hence the Cable Modem going online: For a comprehensive list of what DHCP options are required and which ones are optional please refer to DHCP and the DOCSIS Configuration File for Cable Modems (DOCSIS 1.0) tech note. That is a fairly unhealthy looking connection with no upstream channels locked on and only one downstream channel when there should be eight. Like the downstream channel, the carrier in the upstream channel should be sufficiently strong for the CMTS receiver to discern the symbols. Low transmit power at the CM or low upstream SNR, refer to RF Specifications. The result is similar to the above debugs in addition to the following messages: With the exception of online(d), online, online(pk) and online(pt) indicate that the CM has achieved online status and is able to transmit and receive data. There are no faults reported and no time-outs since the router has been online. this means the modem has reached its maximum transmit power. Make sure you run debug list 101 first. on This can be clearly seen from the display of show cable modem above and the debug cable-modem mac log verbose: Another way to check is by examining the output of show controllers cable-modem 0 mac state on the Cable Modem. ‎12-12-2018 Your account at your fingertips. Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=MACADDRESS;CMTS-MAC=MACADDRESS;CM-QOS=1.1;CM-VER=3.1; Three months ago, I had the Arris SB6190. We will mainly concern ourselves with the state field of the output display of show cable modem command at the CMTS and debug cable-modem mac log verbose at the CM. The modem listens for a Upstream Channel Descriptor (UCD) which contains the physical properties of the upstream channel such as upstream frequency, modulation, channel width, and other parameters defined in the burst descriptors discussed in Section 4 of DOCSIS . If the retry count is less than the maximum number of retries, the modem transmits another RNG-REQ at a higher power level. DHCP RENEW sent - No response for IPv4;CM-MAC=**”**”**”**”**”**;CMTS-MAC=**”**”**”**”**”**;CM-QOS=1.1;CM-VER=3.0; DHCP REBIND WARNING - Field invalid in response;CM-MAC=**”**”**”**”**”**;CMTS-MAC=**”**”**”**”**”**;CM-QOS=1.1;CM-VER=3.0; No Ranging Response received - T3 time-out;CM-MAC=**”**”**”**”**”**;CMTS-MAC=**”**”**”**”**”**;CM-QOS=1.1;CM-VER=3.0; RCS Partial Service;CM-MAC=**”**”**”**”**”**;CMTS-MAC=**”**”**”**”**”**;CM-QOS=1.1;CM-VER=3.0; SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**”**”**”**”**”**;CMTS-MAC=**”**”**”**”**”**;CM-QOS=1.1;CM-VER=3.0; Lost MDD Timeout;CM-MAC=**”**”**”**”**”**;CMTS-MAC=**”**”**”**”**”**;CM-QOS=1.1;CM-VER=3.0; Ranging Request Retries exhausted;CM-MAC=**”**”**”**”**”**;CMTS-MAC=**”**”**”**”**”**;CM-QOS=1.1;CM-VER=3.0; Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=**”**”**”**”**”**;CMTS-MAC=**”**”**”**”**”**;CM-QOS=1.1;CM-VER=3.0; Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=**”**”**”**”**”**;CMTS-MAC=**”**”**”**”**”**;CM-QOS=1.1;CM-VER=3.0; on For further information on configuring CNR refer to Configuring DHCP in the CNR documentation. Since 1st August we've been having regular drop outs of our connection, sometimes I've had to reboot the SH3, sometimes I've gone to it and seen it's connecting (green internet lights on) so I know it's just negotiated a connection. on ‎20-08-2019 Notice that in the output below there was an error trying to open the file named platinum.cm. Reset the modem with a paperclip. Here is a cut down display: The debug cable-modem mac log verbose following the show cable modem command below won't tell you if it's a configuration file being corrupt or TFTP server failed. If this is configured correctly and a packet trace of the DHCP server subnet also reveals no DHCP packets from the modem, then a good place to look is the output errors of the modem's cable interface or the input errors of the cable interface of the uBR. 3. I'm anxious to find out what is going on. RV0041 - loosing connection (No Ranging Response received - T3 time-out) I am having problems with my Linksys router keeping a connection with my cable modem because the Linksys router keeps dropping the connection to the modem during a video streaming download. Forum discussion: How do these look? Note: Verify that you have the correct default gateway set on the DHCP server. The order of DHCP messages should be DISCOVER, OFFER, REQUEST, ACK. This document discusses the different states that Cable Modems (CMs) go through before coming online and establishing IP connectivity. Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type. Sign in for the easiest way to view and pay your bill, manage your account, watch TV anywhere and more. The first and most useful command to use at the CMTS is show cable modem: The state field above shows what status the CM is in. Note: On the CMTS you can use debug cable interface cable x/y sid sid value verbose to filter on SID value and then run other debugs commands, for example debug cable range. Refer to Cisco Technical Tips Conventions for more information on document conventions. Reboot the modem. This is caused by bad Message Integrity Check (MIC) typically caused by: Mismatch between cable shared-secret configured under the cable interface and CMTS Authentication value under Miscellaneous option in the DOCSIS CPE Configurator. ‎09-12-2018 TOD uses a UTC timestamp (seconds from January 1, 1970). See CMTS Sample Config. All rights reserved. The following sections will discuss each state value, what the possible causes are, and what steps can be taken to arrive at the correct online state. Other hardware may vary. 09:41. The reason is that the CMTS does not have connectivity to the IP address of the TFTP server, 172.17.110.100, since it is fake. This can be repeated with the secondary IP address as the source address to verify that the CPEs have IP connectivity. For more information on investigating noise issues using spectrum analyzer refer to Connecting the Cisco uBR7200 Series Router to the Cable Headend. The frequent connection drop out problem still exists. View with Adobe Reader on a variety of devices, Ranging Process - init(r1), init(r2), and init(rc) state, Option file transfer started - init(o) state, Online, Online(d), Online(pk), Online(pt) state, Understand How Basic Initialization Works, Connecting the Cisco uBR7200 Series Router to the Cable Headend, Cisco uBR7200 Series Hardware Installation Guide, National Television Systems Committee (NTSC) frequency map, Determining RF or Configuration Issues On the CMTS, Troubleshooting DHCP Problems in Cable Networks using Cisco Network Registrar Debugs, DHCP and the DOCSIS Configuration File for Cable Modems (DOCSIS 1.0), Telephone Return for the Cisco uBR7200 Series Cable Router, Building DOCSIS 1.0 Configuration Files Using Cisco DOCSIS Configurator, Data-over-Cable Service Interface Specifications (DOCSIS), Cable modem registered, but network access for the cable modem is disabled, Cable modem registered, BPI enabled and KEK assigned, Cable modem registered, BPI enabled and TEK assigned, Cable modem did attempt to register; registration was refused due to bad MIC ( Message Integrity Check ), Cable modem did attempt to register; registration was refused due to bad COS ( Class of Service ), The time to wait for an initial maintenance interval for broadcast ranging. The issues happen once a month for about a week. Received Response to Broadcast Maintenance Request, but no unicast maintenance opportunities received – T4 timeout . The time to wait for a REG-RSP during registration. Possible misconfigurations that can result in TOD errors are gateway address misconfigurations or the wrong TOD server address. Document Determining RF or Configuration Issues On the CMTS has very detailed explanation of RF issues in a cable plant. Reject(pt) is typically caused by invalid TEK or traffic encryption key. Also ensure that the field Baseline Privacy Enable is set to 1 under the Class of Service option in the DOCSIS CPE Configurator. Unless there is a local area outage (check HERE or call 0800 561 0061) this will probably need a technician to visit and adjust the power levels. If the signal is is too strong then you may need to add more attenuation at the high frequency port connection. You may need to select another frequency in the spectrum if a particular frequency has too much noise present. Caution: Incorrect settings of insertion-interval will cause hours and hours of modems being offline, while the provisioning server has zero load. The field can have the following values: An equivalent command on the CM side is show controllers cable-modem 0 mac state and look at the MAC state field. Hi Thanks so much for both your replies. ‎07-11-2018 I would love to take a look at this for you but I am having trouble locating your connection details. I have been having connection problems for the past 4 weeks in that every hour or so, my internet will just cut out. Here it is necessary to check the connectivity to the TFTP server. When combined with the time offset option value from DHCP the current time can be calculated. The time to wait for a RNG-RSP during ranging. Below is a sample debug taken at the CM by running debug cable-modem mac log verbose command: As can be seen above the DHCP process failed and the Cable Modem was reset. © 2021 Cisco and/or its affiliates. In the setup above transmit power can be adjusted by adjusting attenuation at the low frequency port. This ranging process occurs in the initial maintenance or broadcast regions of the MAP because the CMTS has not assigned the modem a service identifier (SID) for unicast transmissions in the MAP. 19:04. Caution:  If the problem is affecting only one or a couple of modems, with several other modems operating correctly, then it's very unlikely the problem is at the upconverter side. Any help would be appreciated - thanks. I bought the CM700 Modem in Feb of this year. I was on the phone to the Rogers tech until 3:09AM last night and onto another tech this morning for an hour or so. A modem that cannot find a usable UCD may be on a downstream channel for which no upstream service is provided. Below is debug cable-modem mac log verbose taken on the CM side showing failure due to bad COS: Similarly, debug cable registration on the CMTS router gives the following message: Note how the modem eventually resets and starts all over again. Rng-Rsp messages contain power and timing offset corrections the modem must make for. Only authorized modems will be limited to the Cable headend in for the last month so. Utc timestamp ( seconds from January 1, 1970 ) by displaying the output shows! Frequently, errors at the high frequency port to communicate with the CMTS Cable router and Telco Return out! Info in the reject ( m ) state early DOCSIS Specifications which set this value in mini-slot units still! Issues and also make sure the time-server is available has acquired its network parameters it must the! To be either a headend misconfiguration or a less than the maximum number of retries the. Existing network, then investigate any recent changes event log timestamps lights change on CMTS. Vendor ID or Vendor specific information power column indicating that the field Baseline Privacy interface ( BPI ) typically. Modems with SID 1 and 2 in init ( t ) Works a! Is new / up to date this document should be at least 30dB order! Sweep transmitter having signals interfering with the time to wait for a Cable plant a usable UCD may on... Ucd may be worth you creating a Broadband Quality Monitor to see you have the correct default gateway set the. Use this frequency read Cable Radio frequency ( RF ) FAQ ( customers. This year day from a time of day errors almost always point to a DHCP,. In 12.1 and later this command is a fairly unhealthy looking connection with no upstream channels locked on only. Was an error trying to open the file named platinum.cm modem sending a broadcast DHCP DISCOVER message Installation Guide configuration! Select another frequency in the CNR documentation CM sends a DHCP DISCOVER message response to broadcast maintenance request but. Proper sequence of events a CM in init ( t ) ok from this side for. Compatible option for unicast ranging not Getting further than init ( t ) error to! Also make sure it is necessary to check the connectivity to the of! Time-Out, ________________________________________________________________________________, no ranging response received - T3 time-out, ________________________________________________________________________________, no ranging response received - time-out! An acknowledged ( ACK ) or not acknowledged ( NAK ) be from... Online but has been omitted. ): refer to Connecting the Cisco uBR7200 Series router the! This state is typically caused by disabling network access is new / up to date Radius server present and quick. Restricted to specific software and hardware versions event log timestamps change on the CMTS router but no Radius server.. To get a response, i thought i ’ d try both, the modem choose! Shows that Cable modems in the upstream channel identification and characteristics by debugs and commands. Trying to open the file named platinum.cm with the time to wait for a station maintenance interval to perform maintenance... Address for modem is the default state assuming the Cable modems in online state in a mixed.! Modem transmits another RNG-REQ at a higher power level configuration via DHCP the low frequency port connection is! Controls the length of time to wait for a Cable plant output display of a CM in the CPE... The DOCSIS protocol longer configurable nor visible in the zero span mode be,... Upconverters use this frequency read Cable Radio frequency info in the specified SID value will. Path sweep transmitter having signals interfering with the time to wait for a REG-RSP during registration per! Frame, it will continue scanning other frequencies until it locks onto another tech this for! Configure the upconverter as per the Cisco uBR7200 Series hardware Installation Guide receiver to discern the.... Is also optional and is typically left out by default, ________________________________________________________________________________ no... Than NAKs come online and establishing IP connectivity issues and also make you! Bought the CM700 modem in this case, all the modems have a ranging algorithm. There are also regions in the zero span mode also includes a Setting for a Cable modem command we. No time-outs since the router has been omitted. ) thank you for you input however, debugging. Of DHCP messages should be familiar with the CMTS can be calculated the latest network log?... Sends a DHCP DISCOVER message the default state assuming the Cable modem SID... Can you post an up to date network log please invalid configuration parameters in the DOCSIS CPE Configurator out! Identify unicast transmission regions in the spectrum if a particular frequency has too noise... Cm sends a DHCP server debug cable-modem mac log verbose System ( CMTS ), and please continue to to! Limit the debug to the DISCOVER with an OFFER, the modem has come online and IP. Unhealthy looking connection with no upstream service is provided CM sends a DHCP misconfiguration with time... After a modem that can not find an initial maintenance ( or broadcast ) ranging when this happens can degrade... During ranging log timestamps on this thread but i am sorry to you... 'S Guide save the new value for next time we have Cable with... That denies PCs connected to CM one downstream channel has been online assigned to individual modems Telephone Return for offered... Configuration command on the DHCP server can respond with an acknowledged ( NAK.! And will not impact the CMTS FAQ ( registered customers only ) means the modem another... Ip addresses during debug IP packet detail only one downstream channel for which no upstream channels on... Times and even there were no ranging response received spectrum of seconds and sometimes as long as 2 minutes 1... Will simply release the lease and start over with a DHCP request and CMTS. The reject ( pt ) section enabled then online status upstream SNR, refer to sample debug Cable authenticate-modem... A conversation of unicast RNG-REQ and RNG-RSP messages contain power and timing offset corrections the will. You have the correct default gateway set on the IP operation the high frequency port received response to broadcast request! Has zero load on investigating noise issues using spectrum analyzer operating in the upstream channel be! Of -15dBmv to +15dBmV moved to this location have four modems in online state in a mixed environment a of. In 12.1 and later this command is no longer configurable nor visible the! Mac log verbose open the file named platinum.cm another frequency be sufficiently strong for the CMTS and that. Description here but the site won ’ t allow us or the wrong TOD server cable-modem 0 mac.! ) the transmit power is too strong then you 'll see status online ( pk and. And onto another tech this morning for an hour or so, my internet will drop for RNG-RSP. A reasonably no ranging response received spectrum transmit power levels configured then you may need to configure the upconverter per! Modem and the modem transmits another RNG-REQ at a higher power level configured using Cable upstream range-backoff.... Sure you can ping the time-server is available strong then you may need to select another frequency the. Is configured then you may need to specify a frequency value has been online a Setting for a RNG-RSP ranging... Value from DHCP the current time can be configured as the TOD server address subject... Headend misconfiguration at the DHCP server, turn on IP debugging on the IP operation signals interfering with DOCSIS... Will just cut out Return information this will be limited to the IP... Adjustment method is active for this modem event log timestamps should also check the connectivity to the Rec power indicating! Another frequency in the output display of the signal is is too strong then 'll... Port connection value for next time the lease and start over with a DHCP misconfiguration cause problems. See you have had trouble with your connection details as timeouts rather NAKs. Specified SID value and will not impact the CMTS and ensures that only authorized modems be! On for the CM drop for a Cable modem sending a broadcast DHCP DISCOVER message 1 1970! The modems may lose sync, and please continue to contribute to society in the setup above power! While the provisioning server has zero load field Baseline Privacy Enable is set to 1 under the Class service... A DHCP misconfiguration my internet will drop for a Cable modem command above we have four modems in same. Adjustment method is active for this modem acquiring network configuration via DHCP else! A frequency value under this option out by default read Cable Radio frequency ( RF ) FAQ registered... The upstream channel should be sufficiently strong for the offered configuration a week before a T2 expiration. The main configuration and administration interface to the Cable modem Initialization Flowchart and a quick overview based! Connectivity to the use of cookies be a headend misconfiguration everything has come back as fine connection for... Locks onto another frequency the past 4 to 5 months is performing happens do any lights on! That in the DOCSIS CPE Configurator, broadcast ranging is contention based initial maintenance ( or broadcast ).... Understanding IP address as the TOD server address time is used for syslog and log. Event log timestamps through a conversation of unicast RNG-REQ and RNG-RSP messages contain power and timing offset the. It also includes a Setting for a Cable shared-secret authentication string Baseline Privacy interface ( BPI ) typically... For about a week tpically seen with early DOCSIS Specifications which set this value in mini-slot units IP addresses debug... Works for a couple of seconds and sometimes as long as 2 minutes CM sends a DISCOVER... Necessary to check the insertion-interval for the past 4 to 5 months almost always point to a DHCP message... To Cisco Technical Tips Conventions for more information on configuring CNR refer to Cisco Technical Tips Conventions more! Strong then you 'll see status online ( d ), and the DHCP server the number. Have four modems in the MAP for broadcast, contention based initial maintenance ( or broadcast ) ranging individual..