Cisco Adsl Crc Error
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Transfer Mode (ATM)Permanent Virtual Circuits (PVC) and Switched Virtual Circuits (SVC)Troubleshoot and AlertsConfiguration Example and TechNotes CRC Troubleshooting Guide for ATM Interfaces Download Print what is crc error in cisco router Available Languages Download Options PDF (15.3 KB) View with Adobe Reader on crc error fix cisco a variety of devices Updated:Nov 15, 2007 Document ID:10434 Contents Introduction Before You Begin Conventions Prerequisites Components Used
Cisco Adsl Modem
ATM Communication Flash Animation: ATM Communication CRC Overview Which CRC Are We Checking? Reasons for ATM CRC Errors Troubleshooting Steps Related Information Introduction This document can help you to determine
Fec Errors Adsl
the reasons behind cyclic redundancy check (CRC) errors on your ATM interface. Before You Begin Conventions For more information on document conventions, see the Cisco Technical Tips Conventions. Prerequisites There are no specific prerequisites for this document. Components Used This document is not restricted to specific software and hardware versions. ATM Communication Flash Animation: ATM Communication Click on ATM communication to cisco switch input errors see a Flash animation on how IP packets segment into ATM cells, how interfaces interpret and reassemble ATM cells into IP, and what happens when cells are lost in transit. CRC Overview The output of show interfaces commands on Cisco devices includes numerous counters. One such counter is CRC, which counts the number of times (that is, for how many packets) the checksum generated by the originating station, or far end device, does not match the checksum calculated from the data received. By doing this, CRC detects changes to a protocol data unit (PDU) during transmission. It is important that we retain the true value of this PDU because we want to ensure that the destination correctly interprets the data that we're communicating. CRC errors typically indicate noise, gain hits or transmission problems on the data link, or on the interface itself. On an ethernet segment, CRC errors result from collisions or from a station transmitting bad data. On an ATM interface, CRC errors also occur when the ATM network provider drops some cells of a total packet in th
Reach Ethernet (LRE) and Digital Subscriber Line (xDSL)LRE/VDSL (Long-Reach Ethernet/Very-high-data-rate DSL)Troubleshoot and AlertsConfiguration Example and TechNotes Troubleshoot VDSL Download Print Available Languages Download Options PDF (23.6 KB) View with
Linksys Adsl
Adobe Reader on a variety of devices Updated:Jun 22, 2015 Document ID:119009 Document ID: what are crc errors 119009 Updated: Jun 22, 2015 Contributed by Sunil C, Cisco TAC Engineer. Download PDF Print Feedback Related ProductsSearch...ContentsIntroductionPrerequisitesRequirementsComponents show controller vdsl 0 explained UsedLayer 1 IssuesIs the carrier detect (CD) light on the front panel of the Cisco DSL Router on or off?Does your ISP use a DSLAM that supports the Broadcom chipset?Is the DSL port http://www.cisco.com/c/en/us/support/docs/asynchronous-transfer-mode-atm/permanent-virtual-circuits-pvc-switched-virtual-circuits-svc/10434-crc-tshooting.html on the back of the Cisco DSL router plugged into the DSL wall jack?What is the controller status, operating mode, and Transmission Coverage (TC) mode?Do you have the correct router model?Is the circuit tested/provisioned correctly?Layer 2 IssuesIs the PTM Ethernet up?Does the provider expect tagged traffic? If yes, what is the Virtual LAN Identifier (VLAN ID)?Is the Address Resolution Protocol (ARP) entry populated?Do you receive data http://www.cisco.com/c/en/us/support/docs/long-reach-ethernet-lre-digital-subscriber-line-xdsl/lre-vdsl-long-reach-ethernet-very-high-data-rate-dsl/119009-technote-vdsl-00.html from your ISP?Does the PPP negotiate properly?No Response from Your ISPLCP Not OpenAuthentication FailureHow do I know if my PAP username and password are correct?How do I know if my CHAP username and password are correct?How do I know when PPP authentication is successful?Performance Issues over PPPoERelated Cisco Support Community DiscussionsIntroductionThis document describes how to configure your Cisco Digital Subscriber Line (DSL) Customer Premise Equipment (CPE) Router for Very High Bit Rate Digital Subscriber Line (VDSL) service. It explains how to troubleshoot VDSL related issues on the Cisco 880 Series, 890 Series, 860 Series, and VDSL/ Asynchronous Digital Subscriber Line (ADSL) Enhanced High Speed WAN interface cards (EHWICs). This document is very specific to VDSL service, though youcan have either ADSL or VDSL service on the above mentioned routers and modules. There are three layers in which the failure can occur:Layer 1 - DSL physical connectivity to your ISP's Digital Subscriber Line Access Multiplexer (DSLAM)Layer 2.1 - Ethernet end-to-end connectivityLayer 2.2 - Point-to-Point Protocol over Ethernet (PPPoE), IP over Ethernet (IPoE), RFC1483 Bridging, or RFC1483 RoutingLayer 3 - IPPrerequisitesRequirementsThere are no specific requirements for this document.Components UsedThis document is not restricted to specific software and hardware versions.The informati
Post #1 of 11 (3189 views) Permalink ATM CRC errors Hi there, we've got an ATM DS3 to Qwest (our telco) for Qwest based T1s and DSL. It's taken ~588 input CRC errors in the last 20 minutes. The count http://www.gossamer-threads.com/lists/cisco/nsp/15744 for the last week was ~140,000 CRC's. I've been unable to match these CRC errors http://nwsmith.blogspot.com/2009/06/using-snmp-with-cisco-router-to.html to the counters for my interfaces. There were about 100,000 CRC's that I couldn't match to any interface except the main atm1/0 interface. We've checked the physical line, Qwest has monitored the port. They are telling me that discarded cells are the cause. If that is the case shouldn't I be able to match the main interface CRC counter to the crc error CRC counters for all my subinterfaces? Any insight would be appreciated. Thanks -- James Hamilton Southwest Cyberport http://www.swcp.com 505-232-7992 andy at xecu Oct27,2004,12:32PM Post #2 of 11 (3119 views) Permalink Re: ATM CRC errors [In reply to] On Wed, 27 Oct 2004, James Hamilton wrote: > Hi there, we've got an ATM DS3 to Qwest (our telco) for Qwest based T1s and > DSL. It's taken ~588 input CRC errors in the last 20 minutes. The count for > cisco adsl crc the last week was ~140,000 CRC's. I've been unable to match these CRC errors > to the counters for my interfaces. There were about 100,000 CRC's that I > couldn't match to any interface except the main atm1/0 interface. > > We've checked the physical line, Qwest has monitored the port. They are > telling me that discarded cells are the cause. If that is the case shouldn't > I be able to match the main interface CRC counter to the CRC counters for all > my subinterfaces? Any insight would be appreciated. No, CRC errors are not associated with discarded cells. That's ridiculous. CRC is a method of verifying the packets were transmitted properly by verifying the supplied checksum against the calculated checksum. Demand escalation if that's the nonsense you're being fed. Chances are, it's running too hot. How long is the cable? You may find, if it's a very short run, that the either you need to insert some attentuators, or preferrably, get Qwest to adjust the LBO on their equipment. Andy --- Andy Dills Xecunet, Inc. www.xecu.net 301-682-9972 --- tony at aloha Oct27,2004,12:34PM Post #3 of 11 (3127 views) Permalink Re: ATM CRC errors [In reply to] On Wed, 27 Oct 2004, James Hamilton wrote: > Hi there, we've got an ATM DS3 to Qwest (our telco) for Qwest based T1s and > DSL. It's taken ~588 input
work. We're trying to run an Ipsec tunnel across the ADSL line to connect to one of our small branch offices. Every few hours we would have problems, with the tunnel dropping out. Restarting the router would often fix the problem, but the problems never went away for long.We were using good quality Cisco 1801 routers. The most useful command for debugging is 'show dsl interface atm0' and 'show int atm0'. Below is some typical output, while the ADSL line was faulty:#show int atm 0ATM0 is up, line protocol is up Hardware is MPC ATMSAR (with Alcatel ADSL Module) MTU 4470 bytes, sub MTU 4470, BW 832 Kbit/sec, DLY 440 usec, reliability 255/255, txload 41/255, rxload 6/255 Encapsulation ATM, loopback not set Encapsulation(s): AAL5 AAL2, PVC mode 23 maximum active VCs, 1024 VCs per VP, 1 current VCCs VC Auto Creation Disabled. VC idle disconnect time: 300 seconds Last input never, output 00:00:00, output hang never Last clearing of "show interface" counters never Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 48 Queueing strategy: Per VC Queueing 5 minute input rate 22000 bits/sec, 20 packets/sec 5 minute output rate 137000 bits/sec, 24 packets/sec 322340 packets input, 50047091 bytes, 0 no buffer Received 0 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 182 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 345336 packets output, 145468959 bytes, 0 underruns 0 output errors, 0 collisions, 0 interface resets 0 output buffer failures, 0 output buffers swapped out#show dsl interface atm0ATM0Alcatel 20190 chipset information ATU-R (DS) ATU-C (US)Modem Status: Showtime (DMTDSL_SHOWTIME)DSL Mode: ITU G.992.1 (G.DMT) Annex AITU STD NUM: 0x03 0x2Vendor ID: 'STMI' 'P 'Vendor Specific: 0x0000 0x0000Vendor Country: 0x0F 0xB5Chip ID: C196 (0)DFE BOM: DFE3.0 Annex A (1)Capacity Used: 100% 85%Noise Margin: 1.0 dB 11.0 dBOutput Power: 20.0 dBm 12.5 dBmAttenuation: 34.0 dB 17.0 dBDefect Status: None NoneLast Fail Code: NoneWatchdog