Cable Modem Terminate SystemSetup: Devil_huang

What is CMTS ?1The RouterGatewayCable Modem Terminate System (CMTS)

1.The Router2Route data between a cable modem network and a head-end internetwork 2.GatewayCMTS provides the encapsulation and de-capsulation of DOCSIS traffic.In upstream traffic ,it translates DOCSIS data to IP data then forwards to backbone network.In downstream traffic , it translates IP data to DOCSIS data and forwards the result to a cable modem.

Simplified Cable Headend Configuration for Two-way Data3

CMTS functionPerforming MAC and PHY reception and transmission functionsPacket classificationPriority queuingModificationFilteringRoutingPriority routingProxy services4Data encryptionEncapsulating packets in the data link layerExtracts Ethernet packetsTunes each upstream channelDemodulates upstream dataModulates downstream dataAdding forward error correction

Abbreviation5CMTS: Cable Modem Terminate SystemCM: Cable ModemDOCSIS: Data Over Cable Service Interface SpecificationDHCP: Dynamic Host Configuration ProtocolCPE: Customer Premises EquipmentISP: Internet Service ProviderTFTP: Trivial File Transfer ProtocolTOD: Time Of DateARP: Address Resolution ProtocolAAI: Aggregate Access InterfaceMIC: Message Integrity CheckCA: Certificate AuthoritySNMP: Simple Network Management ProtocolBPI: Baseline Privacy InitializationACL: Access Control List CLI: Command Line InterfaceQoS: Quality Of ServiceCMS: Call Management ServerRKS: Record Keeping serverMIB: Management Information Base

ArchitectureMSO Backbone Network Next-hop Router DHCP/FTP/WEB Server ISPCM Access Network CPE CM 6

Packet-Cable Functionality chart

Sample Network

What should be specify ?Cable Access Interface Fast Ethernet Interface Backbone Router DHCP / TFTP / TOD / Log server MIC Configuration Privacy Configuration RF Configuration CMTS Unit Interfaces9

Logging In CMTS Privilege modes Non-privileged Mode:can access all reports and diagnostics cannot modify the system configuration Privileged Mode: can modify the system configuration Logging In Type enable puts the CLI in Privileged mode. Need password to access Type config terminate to get into the configuration context. And type username devil password letmein to create new user account. Type do show username to verify the account.10

Configuring A Backbone Fast Ethernet Interface Type configure t to get into configuration context , where you can start configuring Type interface fastethernet {0/0/0 | 0/0/1| 0/0/2 | 0/0/3} This command identifies specific fast Ethernet interface you are about to configure. Type ip address a.b.c.d e.f.g.h This command identifies a.b.c.d as the fast Ethernet s IP address, e.f.c.d as its subnet mask. Type do show interface ip to verify the configuration Type no shutdown to enable the interface. Example: Terayon CMTS(config-if 0/0/0) # ip add 192.168.24.11 255.255.255.011

Configuring the Next-Hop RouteThe next-hop route defines the backbone router the CMTS is connected to.In the factory , it always be combined to the server directly.So the route IP address will be replaced with the servers IP address.Type ip route {network prefix} {netmask} {next-hop route IP address}Example: Terayon CMTS (config)# ip route 0.0.0.0 0.0.0.0 192.168.24.12.In this example ,network prefix and netmask are fill with 0. This identifies all packet data should route to 192.168.24.12.12

AAI conceptAggregate Access InterfaceCable modem access interface provided by CMTS.Handles the routing of IP packets to the multiple physical cable interface ,thus keeping the HFC-plant configuration independent of the IP address domains.You can configure the baseline IP network to use a private or non-routable network IP address for CMs only. This avoids the use of public IP addresses for CMs13

Aggregated Access Interface

Configuring the AAIType interface access 0 to get into the access configuration context. Type ip address a.b.c.d e.f.g.h to identifies the CM access network IP Type ip address a.b.c.d e.f.g.h secondary to identifies the CPE access network IP Type cable helper-address {ip-address} [cable-modem | host] to identifies the DHCP servers address. Example: Terayon CMTS(config-if-AAI-0)# cable helper 192.168.24.1215

Configuring the AAIConfigure the gateway interface address (giaddr) for the CM and CPE access networks on the global Aggregated Access using the command: cable dhcp-giaddr {policy | primary}If you select policy , the CM and CPE networks use a different giaddr .If you select primary , the CM and CPE networks use the same giaddr.Example: Terayon CMTS ( config-if-AAI-0) # cable dhcp- giaddr policy16

MIC configuringType interface cable CMTS unit number to specify the unit you want to configure. Type cable shared-secret word to specify the shared-secret authentication string. Use no prefix to disable MIC. Example: Terayon CMTS (config-if-1) # cable shared-secret DOCSIS Default string. annex A : Euro-DO annex B : DOCSIS One of the many features the CMTS has is its ability to verify the authentication of a DOCSIS modem. This is accomplished through the authentication string the modem downloads in its configuration file.The authentication string is encrypted , then the modem transmits the string to the CMTS for verification. The process is called Message Integrity Check.

RF ConfigurationType interface cable CMTS unit number to specify the unit you want to configure.Downstream configuration Type cable downstream frequency to specify the center frequency of the downstream channel. The valid ranges for the value are : for no.America and Japan for Europe. Type cable downstream power to specify the power level that CMTS output. Use the following command to set the downstream modulation type cable downstream modulation {64qam | 256qam}

RF ConfigurationUpstream configuration Type cable upstream {0-3} {0|1} frequency to specify the upstream center frequency. The parameter {0-3} indicates the physical upstream port you are configuring The parameter {0|1} indicates the channel mode to which the center frequency will apply. 0 for TDMA 1 for S-CDMA The frequency values valid ranges are: for North-America for Europe for Japan

RF ConfigurationVerify the US / DS center frequencies Terayon CMTS (config-if-1)# do show cable 1 upstream 0 0 Terayon CMTS (config-if-1)# do show cable 1 upstream 0 1 Terayon CMTS (config-if-1)# do show cable 1 downstreamEnabling the interface Type no shutdown to enable CMTS unit interfaces.

RF ConfigurationExample: Terayon CMTS (config-if-1)#cable upstream 0 0 freq 30000000 Terayon CMTS (config-if-1)#cable downstream freq 802000000 Terayon CMTS (config-if-1)# no shutdown This command enables the CMTS Unit MAC interface Terayon CMTS (config-if-1)# no cable upstream 0 shutdown Terayon CMTS (config-if-1)# no cable upstream 0 0 shutdown Terayon CMTS (config-if-1)# no cable downstream shutdown

DOCSIS 1.0 / 1.1 /2.0 Item upstream BPI

DOCSIS1.0 TDMA disableDOCSIS1.1 TDMA enableDOCSIS2.0 S-CDMA enable

Viewing Status Viewing Cable Interface Status Terayon CMTS(config-if-1) # do show interfaces cable Intf Type MTU Speed MACaddr. Oper Admin status (bps) status status

Viewing Cable Modem Status do show cable modem MAC IP Cable Prim Chan MAC Timing RxPwr Unm Address Address I/F SID Mode State offset (db) CPE

00e0.6f23.72c0 111.121.1.200 1/1/0/0 8 tdma online(t) 285 0 1

BPI Baseline Privacy Initialization Security is an issue of prime importance with the CMTS. By the term security we mean access and privilege levels ,authentication ,network privacy ,data filtering, and hostile-attack protection.download configuration file from server to determine enable BPI or disable. Use the cable privacy command to enter the configuration for privacy and BPI

Configuring cable privacy Create a list of trusted / un-trusted cable modem Use the cable privacy hotlist command to create a list (Hotlist) of un-trusted cable modem Cable modem on the Hotlist are never authorized and are always denied service. Use the cable privacy trusted-list command to create a list (trusted-list) of trusted cable modem Cable modem on the trusted-list are always authorized for service and no authentication checking is performed. The same cable modem cannot be entered on both Hotlist and Trusted-list lists. Terayon CMTS(config)# [no] cable privacy hotlist H.H.H {manufacturer cert-ref-no} . Where H.H.H specifies a MAC address and cert-ref-no is the reference number assigned to this Manufacturers Certificate.

Configuring cable privacy Certificate Use the cable privacy certificate {root | manufacturer} cert-ref-no command to enable or disable CA certificates. The CMTS maintains a list of known certificates classified in three categories,Root and Manufacturer Certificates. Root Certificates added are marked as root and by default marked trusted.for operation purposes , the system requires only one active Root Certificate. Manufacturer Certificates added are marked as trusted by default.The command cable privacy hotlist allows marking a Certificate as un-trusted.

Configuring cable privacy Certificate (continue) Manufacturer Certificates can be added/ modified.When the certificate be added , a unique reference number is automatically assigned to it and displayed on the command line.This reference number may be used later to display information about this certificate or to delete this certificate from the database. Example: Terayon CMTS(config)# cable privacy certificate root cert-ref-no 2 for American or Japan. Terayon CMTS(config)# cable privacy certificate root cert-ref-no 3 for Europe.

Configuring cable privacy Self-signed Certificates The CMTS policy to accept self-signed manufacturer certificates from cable modems at authorization time.Use the accept-self-signed-certificate command to accept self-signed manufacturer certificates. It is always set on a per-cable-line-card basis. Enabling the Validity Period Check The CMTS verifies the validity period of cable modem certificates( at KEK exchange times), using its time-of-day clock as the time reference for the verification. Use the validity-period-check command to force verification of the modem certificate validity period.

Configuring cable privacy Key Encryption Key/Traffic Encryption Key lifetime When BPI is enabled (in the cable modem configuration file),the CMTS and the cable modem use authorization and encryption / decryption for packet across the HFC interface.The BPI is configured with KEKs and TEKs. A KEK is assigned to a cable modem based on the cable modems service identifier(SID) and permits the connection when baseline privacy is activated. The TEK is assigned to a cable modem when its KEK has been established.It is used to encrypt data traffic between cable modems. KEK and TEK can be set to expire based on a lifetime value.New keys are requested before the current ones expire. Use the no form of the command to return to the default condition .

Configuring cable privacy Setting the Registration Timeout Use the registration-timeout command to set the value of the DOCSIS registration timeout timer(T9 timeout) on a particular interface. The registration timeout is the time allowed between the CMTS sending a RNG-RSP (ring-response success) to a CM and receiving a REG-REQ(registration request) from that same CM. Configuring the Shared Secret String(MIC) Use the default cable shared-secret command to set the default shared secret string.

Configuring cable privacySetting UP Basic Access Control Lists This allows defining a list of host names or IP address to be permitted or denied access.Display and diagnose security parameters Displaying Privacy certificates show cable privacy certificate {root | manufacturer cert-ref-no} show cable privacy certificate modem H.H.H Displaying Interface Privacy Information show cable privacy interface

The modem configuration file The modem configuration file is stored as a binary file.It can be edited using a special tool. Use a designated TFTP server to make your modem configuration file available for remote configuration. Example setting for DOCSIS2.0 modem: Privacy Enable(29) =0 Service Flow Reference(24.1) = 1 Quality of Service Parameter Set Type (24.6) = 7 Network Access Control Object(3) = 1 Maximum Number of CPEs (18) = 2 Upstream Service Flow encoding(24) Downstream Service Flow Encoding(25) Service Flow Reference (25.1) = 5 Quality of Service Parameter Set Type (25.6) = 7

The DHCP Relay Agent Each modem and host can get an IP address and IP information from a DHCP server connected to the CMTS.The CMTS servers as a relay agent between the DHCP server and the modems and implements the DHCP/BootP relay agent.

The DHCP Relay Agent

Address Resolution Protocol Function The CMTS supports the ARP protocol, a protocol used to obtain a device physical (layer 2 MAC) address based on its logical (layer 3 IP) address.In short,ARP binds high level IP address to low level physical address.However , the CMTS handles ARP differently for the backbone , management, and cable interface. Entries both for CM and CPE. Each ARP table entry associates a single IP address with a singe host. Supporting Dynamic and Static ARP entries Extended ARP type ARP learning

ARP Function

ARP configurationAging timeout This allows you to set the threshold when you want dynamic ARPs to age out Terayon CMTS(config)# arp timeout . Where is the timeout value in seconds. The value 86401 indicates that there is no timeout and the dynamic ARPs do not age out.

ARP configuration Proxy ARP The Proxy ARP feature works on only the cable network side of the CMTS. This reduces network ARP traffic overhead ,thus improving network performance, and at the same time increases network security When a cable network host send an ARP request to the CMTS, instead of broadcasting that request to the cable modem network ,the CMTS responds to the ARP request and then relays the request to the appropriate host on the cable network.In the host ARP tables, the destination MAC address is always the CMTS MAC address The default condition of the Proxy ARP feature is enabled

ARP configurationARP Learning feature This enables you to stop clients that obtain IP addresses via dynamic ARP from passing traffic,thus forcing the client (CPE) to obtain an IP address via a DHCP transaction. If you disable ARP Learning on the access side, the CMTS ARP table entries only from Static ARP and DHCP ARP assignments.Dynamic ARPs and host MAC addresses for Static-host ARPs are not learned. The ability to enable and disable ARP Learning gives you strict control over ARP table entries,resulting in a higher degree of protection against IP address spoofing.(unauthorized devices attempting to steal or mimic a valid IP address). The default condition for ARP learning on the access side is enabled

ARP configurationClear ARPs on Modem Reset You may configure the CMTS to clear (remove) CPE ARPs whenever a cable modem resets. This may be useful when the IP limit for a modem is 2 or greater If the Lease Query (source IP address verification) feature is disabled ,then enabling the ARP clear-on-reset feature has no effect. Terayon CMTS(config)# arp clear-on-reset

Server Configuration Operating System (OS) Win2000 professional Service Path 4 Internet Information Services. Win2000 Server Win2000 Advance Server Software Cisco Network Register 3.0 (DHCP Server) tardis2000nt (TOD Server) TFTP 2000 (TFTP Server)

Server Configuration Internet Information Services HTTP support Web service FTP support

Setup1. Start 2. Setting 3.Control Panel 4. Add/Remove Programs 5.Add/Remove Windows Component 6.Windows Component Wizard 7.Select IIS 8. Press Next Finish FTP service Scripts support POP3 / SMTP support

IIS setup

IIS setup

IIS setup After finished software install.The following folders will be created in disk C. Inetpub FTProot WWWroot The file which named default.htm in WWWroot will used as the web servers default web. The files in FTProot will displayed in FTP servers folder.

IIS setupDefault.htm

FTP Configuration Enabling FTP service 1.Start 2. Setting 3.Control Panel 4. Administrative tools 5.Service 6. Select FTP Publishing Service 7.Start the service 8. Set the start-up type automatic Finish Copy files you want to shell to FTProot.

Enabling FTP service

Enabling FTP serviceFTP Publishing Service

DHCP Configuration Software setup Login in the system Add scope Policy configuration Time offset Router DHCP lease time Time Server Packet file name Log server Use interface configuration

TOD setupLog into your Windows NT system as a user with administrative privileges. Tardis 2000 NT must be installed and configured by someone with administrative privileges. Run the tardis2000NT.exe program and Tardis 2000 will automatically be installed. Choose start service / stop service as show in the following figure

Run Tardis 2000 NT

TFTP setup If you use TFTPD32.exe , Start the program at the same path of the CM configuration file If you use TFTP server pro 2000 ,configured the input path as the CM configuration files location

Troubleshooting Understand show command Responses show cable modem show interface cable show cable privacy show arp show run Understand CM online procedure Understand CM online message Troubleshooting Cable Modem State

Troubleshooting Cisco CM State Offline State Ranging Process init(r1),init(r2),init(rc)state DHCP init(d) , init ( i ) state TOD exchange: init(t) state Option file transfer started : init (o) state Online Online , Online(d) ,Online(pt) state Reject reject(pk) , reject(pt) , reject(m) ,reject(c) state

Troubleshooting Terayon CM State Offline Offline , Offline(lr) , offline (ad) state Ranging Process init(r ) ,init(rc) ,init(ds) ,init(os) ,init(ip) state Online Online(pd),Online(tek) ,Online(kek) ,Online(t)

Troubleshooting Offline state most common reasons Weak carrier signal ( too much noise ). Incorrect Downstream Center Frequency 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 Offline (lr) & Offline (ad) Offline (lr) :The line-card on which the modem came up on last time was deleted. Offline (ad): The modem is denied access. Check the configuration file of the modem.

Troubleshooting Ranging process 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 Cisco init(r1) : Cable modem sent initial ranging init(r2) : Cable modem is ranging init(rc) : Cable modem ranging complete Terayon init(r ) : The modem is in ranging modem

Troubleshooting DHCP state After successful ranging ,it needs to acquire network configuration via DHCP. The CM sends a DHCP request and the CMTS relays those DHCP packets in both direction. DHCP request received Cisco : init (d) Terayon init (rc) : the modem is unable to get a DHCP address. init (ds) : DHCP discover is sent and waiting for offer.

Troubleshooting DHCP request received state most common reason. Missing cable helpler-address command on the CMTS or incorrect < IP-address> DHCP server down IP connectivity issue from the CMTS to the DHCP server Wrong default gateway configured at the DHCP server Low transmit power at the CM or low upstream SNR,see RF Specifications DHCP server overload DHCP server is out of IP addresses Reserved IP address for modem is inside wrong scope.

TroubleshootingDHCP reply received ; IP address assigned Cisco: init( i ) Terayon : init( os ) Most common reason Incorrect or invalid DOCSIS file specified in the DHCP server TFTP server issues , for example incorrect ip address,TFTP server unreachable Problems getting TOD or Timing Offset Incorrect Router setting in the DHCP configuration

Troubleshooting TOD exchange init( t ) state You can only see this at Ciscos CMTS Almost always point to a DHCP mis-configuration Wrong TOD server address TOD server is unavailable.

Troubleshooting Option file transfer started state Cisco : init ( o ) Terayon : init (ip) Most common reason Incorrect,corrupt (for example: ASCII instead of binary), or missing DOCSIS configuration file. Unable to reach the TFTP server ,either is unavailable , too busy or no IP connectivity Invalid or missing Configuration Parameter in DOCSIS file Wrong file permissions on the TFTP server

Troubleshooting Online state Cisco online : Cable modem registered , enabled for data online(d) : Cable modem registered ,but network access for the cable modem is disabled online(pk): Cable modem registered , BPI enabled and KEK assigned online(pt) : Cable modem registered,BPI enabled and TEK assigned Terayon online(pd) online(tek) online(kek) online(t)

Troubleshooting Reject state Cisco Reject(pk) and Reject(pt) state Reject(m) Most common reason Reject(pk) and Reject(pt) state Some problem with the BPI configuration Reject(m) Some problem with the MIC

Troubleshooting Full of log application program log Clear log at the server CM record log Clear log at CMTS Example: Terayon CMTS # clear cable modem offline delete

Thank you !Devil