cable modem terminate system setup : devil _huang

Cable Modem Terminate System

Setup

主講 : Devil_huang

What is CMTS ?What is CMTS ?

1

1. The Router

2. Gateway

Cable Modem Terminate System (CMTS)

1.The Router1.The Router

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Route data between a cable modem network and a head-end internetwork

2.Gateway2.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.

3Simplified Cable Headend Configuration for Two-way Data

CMTS functionCMTS function Performing MAC and PHY

reception and transmission functions

Packet classification Priority queuing Modification Filtering Routing Priority routing Proxy services

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Data encryption Encapsulating packets in the

data link layer Extracts Ethernet packets Tunes each upstream channel Demodulates upstream data Modulates downstream data Adding forward error correction

AbbreviationAbbreviation

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CMTS: Cable Modem Terminate System

CM: Cable Modem

DOCSIS: Data Over Cable Service Interface

Specification

DHCP: Dynamic Host Configuration Protocol

CPE: Customer Premises Equipment

ISP: Internet Service Provider

TFTP: Trivial File Transfer Protocol

TOD: Time Of Date

ARP: Address Resolution Protocol

AAI: Aggregate Access Interface

MIC: Message Integrity Check

CA: Certificate Authority

SNMP: Simple Network

Management Protocol

BPI: Baseline Privacy Initialization

ACL: Access Control List

CLI: Command Line Interface

QoS: Quality Of Service

CMS: Call Management Server

RKS: Record Keeping server

MIB: Management Information Base

ArchitectureArchitecture

MSO Backbone Network Next-hop Router DHCP/FTP/WEB Server ISP

CM Access Network CPE CM

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Packet-C

able Functionality chart

Sample NetworkSample Network

What should be specify ?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 Interfaces

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Logging In CMTSLogging 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. A

nd type username devil password letmein to create new user account. Type do show username to verify the account.

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Configuring A Backbone Fast Configuring A Backbone Fast Ethernet InterfaceEthernet 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 y

ou 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 RouteConfiguring the Next-Hop Route

The 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 server’s 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.

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AAI conceptAAI concept

Aggregate Access Interface Cable modem access interface provided by CMTS. Handles the routing of IP packets to the multiple physic

al 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 CMs

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Aggregated Access InterfaceAggregated Access Interface

Configuring the AAIConfiguring the AAI Type interface access 0 to get into the access configu

ration context. Type ip address a.b.c.d e.f.g.h to identifies the CM a

ccess network IP Type ip address a.b.c.d e.f.g.h secondary to identifie

s the CPE access network IP Type cable helper-address {ip-address} [cable-mod

em | host] to identifies the DHCP server’s address. Example: Terayon CMTS(config-if-AAI-0)# cable he

lper 192.168.24.12

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Configuring the AAIConfiguring the AAI

Configure 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 di

fferent giaddr . If you select primary , the CM and CPE networks use th

e same giaddr.

Example: Terayon CMTS ( config-if-AAI-0) # cable dhcp- giaddr policy

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MIC configuringMIC configuring Type interface cable CMTS unit number to spe

cify 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 ConfigurationRF Configuration Type 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 :– <91MHz – 857MHz> for no.America and Japan– <112MHz – 858MHz> 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 ConfigurationRF 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 value’s valid ranges are:• <5MHz – 42MHz> for North-America• <5MHz – 65MHz> for Europe• <5MHz – 55MHz> for Japan

RF ConfigurationRF Configuration

Verify the US / DS center frequencies Terayon CMTS (config-if-1)# do show cable 1 ups

tream 0 0 Terayon CMTS (config-if-1)# do show cable 1 ups

tream 0 1 Terayon CMTS (config-if-1)# do show cable 1 do

wnstream

Enabling the interface Type no shutdown to enable CMTS unit interfaces.

RF ConfigurationRF Configuration

Example: Terayon CMTS (config-if-1)#cable upstream 0 0 freq 300000

00 Terayon CMTS (config-if-1)#cable downstream freq 8020000

00 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 shutdow

n Terayon CMTS (config-if-1)# no cable downstream shutdown

DOCSIS 1.0 / 1.1 /2.0DOCSIS 1.0 / 1.1 /2.0

Item upstream BPI

DOCSIS1.0 TDMA disable

DOCSIS1.1 TDMA enable

DOCSIS2.0 S-CDMA enable

Viewing StatusViewing 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 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 privacyConfiguring cable privacy

Create a list of trusted / un-trusted cable modem Use the cable privacy hotlist command to create a list (Hotlis

t) of un-trusted cable modem Cable modem on the Hotlist are never authorized and are al

ways denied service. Use the cable privacy trusted-list command to create a list (tr

usted-list) of trusted cable modem Cable modem on the trusted-list are always authorized for se

rvice and no authentication checking is performed. The same cable modem cannot be entered on both Hotlist an

d Trusted-list lists. Terayon CMTS(config)# [no] cable privacy hotlist H.H.H {m

anufacturer cert-ref-no} . Where H.H.H specifies a MAC address and cert-ref-no is the reference number assigned to this Manufacturer’s Certificate.


Certificate– Use the cable privacy certificate {root | manufacturer} cert-ref-no comma

nd to enable or disable CA certificates.– The CMTS maintains a list of known certificates classified in three categ

ories,Root and Manufacturer Certificates.– Root Certificates added are marked as ‘root’ and by default marked truste

d.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’.


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-re

f-no 2 for American or Japan. Terayon CMTS(config)# cable privacy certificate root cert-re

f-no 3 for Europe.


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.


Key Encryption Key/Traffic Encryption Key lifetime– When BPI is enabled (in the cable modem configuration file),the C

MTS 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 modem’s 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 .


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.


Setting 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 fileThe 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:

o Privacy Enable(29) =0 o Service Flow Reference(24.1) = 1o Quality of Service Parameter Set Type (24.6) = 7o Network Access Control Object(3) = 1 o Maximum Number of CPEs (18) = 2 o Upstream Service Flow encoding(24) o Downstream Service Flow Encoding(25)o Service Flow Reference (25.1) = 5 o Quality of Service Parameter Set Type (25.6) = 7

The DHCP Relay AgentThe 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 AgentThe DHCP Relay Agent

Address Resolution Protocol FunctionAddress 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 FunctionARP Function

ARP configurationARP configuration

Aging timeout – This allows you to set the threshold when you wan

t dynamic ARPs to age out

– Terayon CMTS(config)# arp timeout <30-86401>. Where <30-86401> is the timeout value in seconds. The value 86401 indicates that there is no timeout and the dynamic ARPs do not age out.


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 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


Clear 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) feat

ure is disabled ,then enabling the ARP clear-on-reset feature has no effect.

– Terayon CMTS(config)# arp clear-on-reset

Server ConfigurationServer 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 ConfigurationServer 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 setupIIS setup

IIS setupIIS 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 server’s default web.

The files in FTProot will displayed in FTP server’s folder.

IIS setupIIS setupDefault.htm

FTP ConfigurationFTP 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 Enabling FTP serviceservice

Enabling FTP Enabling FTP serviceservice

FTP Publishing Service

DHCP ConfigurationDHCP 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 setupTOD setup

Log 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 NTRun Tardis 2000 NT

TFTP setupTFTP 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 file’s location

TroubleshootingTroubleshooting

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

TroubleshootingTroubleshooting 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


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)


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 t

he 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 fi

le of the modem.


Ranging process At this stage , the CM begins a ranging process to calculate th

e 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


DHCP state After successful ranging ,it needs to acquire network configur

ation 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.


DHCP request received state most common reason.

Missing cable helpler-address <IP-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.


DHCP reply received ; IP address assigned Cisco: init( i ) Terayon : init( os )

Most common reason Incorrect or invalid DOCSIS file specified in the DHCP serve

r TFTP server issues , for example incorrect ip address,TFTP se

rver unreachable Problems getting TOD or Timing Offset Incorrect Router setting in the DHCP configuration


TOD exchange – init( t ) state You can only see this at Cisco’s CMTS Almost always point to a DHCP mis-configuration Wrong TOD server address TOD server is unavailable.


Option file transfer started state Cisco : init ( o ) Terayon : init (ip)

Most common reason Incorrect,corrupt (for example: ASCII instead of binary), or m

issing DOCSIS configuration file. Unable to reach the TFTP server ,either is unavailable , too b

usy or no IP connectivity Invalid or missing Configuration Parameter in DOCSIS file Wrong file permissions on the TFTP server

TroubleshootingTroubleshooting Online state

– Cisco online : Cable modem registered , enabled for data online(d) : Cable modem registered ,but network access for the cabl

e modem is disabled online(pk): Cable modem registered , BPI enabled and KEK assign

ed online(pt) : Cable modem registered,BPI enabled and TEK assigned

– Terayon online(pd) online(tek) online(kek) online(t)


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


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 !Thank you !

Devil

cable modem terminate system setup : devil _huang

Documents

configuration type

ip data

system cmts slide

interface ip

twoway data slide

type ip

docsis data

route data