CDRouter Support

CDRouter DOCSIS User Guide

user-guide version 10.4

Introduction

CDRouter DOCSIS adds provisioning and additional testing capabilities to CDRouter. CDRouter DOCSIS is designed to support and test DOCSIS compliant devices that include cable modem (CM) and optionally embedded router (eRouter) interfaces.

CDRouter DOCSIS includes a number of additional protocol test modules that target the CM interface of the DUT. The DOCSIS test modules can be run either individually or as part of a larger test run that includes test cases from CDRouter and other CDRouter add-ons such as:

  • CDRouter Multiport
  • CDRouter Performance
  • CDRouter IPv6
  • CDRouter TR-069
  • CDRouter IKE
  • CDRouter SNMP
  • CDRouter Storage
  • CDRouter BBF.069

Terminology

CDRouter DOCSIS introduces a few new terms which are defined here:

Term Definition
APM Advanced Provisioning Mode
CM Cable Modem
CMTS Cable Modem Termination System
DOCSIS Data Over Cable Service Interface Specification
DPM Dual-Stack Provisioning Mode
eMTA Embedded Multimedia Terminal Adapter
eRouter Embedded Router
MDD MAC Domain Descriptor
NMS Network Management System
TLV Type Length Value

Requirements and License

CDRouter DOCSIS is available for CDRouter 10.3 and newer releases only, and is compatible with all systems that meet the current system requirements listed here.

Licensing

CDRouter DOCSIS is a licensed add-on that must be purchased from QA Cafe. For information on upgrading a license to include CDRouter DOCSIS or any other add- ons, please contact sales@qacafe.com.

CDRouter will report the status of all available add-ons during the installation process and during start-up. To verify that CDRouter DOCSIS is enabled on a system, run the command cdrouter-cli -info as root and look for the line DOCSIS is enabled, as shown below. If this line is present, CDRouter DOCSIS is enabled and ready to use.

$ cdrouter-cli -info

Starting cdrouter-cli Mon Feb 20 15:51:38 EST 2017
Copyright (c) 2001-2017 by QA Cafe
Version 10.3 build 1 (23677 trunk), built 2017-02-19 17:36:43 by nightly@cdr-forge6.lan (x86_64)
OS is CentOS 6.8 (3.10.103-1.el6.elrepo.x86_64)
CPU is Intel(R) Core(TM)2 CPU E8400 @ 3.00GHz
Trying to load modules from '.'
Trying to load modules from '/usr/share/doc/cdrouter'
Start command: /usr/cdrouter/bin/cdrouter-cli -info
Test Suite cdrouter 10.3.1
The system ID is b24fa0b6bc7e4558a1584f6bcdc30d5e
Using license installed at: /etc/cdrouter.lic
Serial number: NTA1000-10093
Registered to: qacafe
Maintenance, Support and Upgrades until: 2018-02-01
Licensed to run: cdrouter
    Multiport   is enabled
    IPv6        is enabled
    Storage     is enabled
    IKE         is enabled
    TR69        is enabled
    TR69-EDM    is enabled
    Nmap        is enabled
    BBF.069     is disabled
    SNMP        is enabled
    Performance is enabled
    ICS         is enabled
    DOCSIS      is enabled
NTA platform 1, image 4.3, serial number NTA1000-10093
BBF.069 is not installed

Alternatively, the Admin > System menu within the web interface can also be used to see a full list of all add-ons installed and available on a system.

Additional Add-ons

Some CDRouter DOCSIS test modules require the IPv6, SNMP, and Nmap add-ons. If these add-ons are not licensed and installed any DOCSIS specific tests that require them will be automatically skipped by CDRouter.

Please contact sales@qacafe.com for more information on the IPv6, SNMP, and Nmap add-ons for CDRouter.

Test Methodology

Overview

Within a DOCSIS network the cable modem (CM) resides within the customer premises and acts as a bridge between the subscriber’s home network and the ISP’s network. Multiple CPE devices, such as computers, wireless routers, VoIP adapters, and set-top boxes can be connected to the LAN port of the CM and gain access to the WAN. CPE functionality can also be embedded into a single device along with the CM. An embedded wireless router is referred to as an eRouter; likewise, an embedded VoIP adapter is referred to as an eMTA.

To test DOCSIS devices with CDRouter, a cable modem termination system (CMTS) is required. A CMTS is the head-end of a DOCSIS network that resides within, and connects multiple CMs to, the ISP’s network. A CM must establish a physical layer connection with the CMTS and be properly provisioned before any attached or embedded CPE devices can forward traffic.

In a test environment, a CMTS is typically installed in a lab and shared among many different users and devices, as shown in the following network diagram:

Typical DOCSIS lab testing environment

In these environments CDRouter has historically required that the CM be fully provisioned by existing systems prior to running any tests. Once provisioned, CDRouter can then be used to test the CM (as a simple bridge), the eRouter (if present), or other CPE devices connected to the CM.

CDRouter DOCSIS adds a provisioning system to CDRouter. All of the services required to fully provision a CM over IPv4 or IPv6 are provided, including:

  • DHCP/DHCPv6 server
  • TFTP server
  • RFC 868 Time server
  • Log server

These servers reside within a new, independent, DOCSIS network that is logically attached to CDRouter’s main WAN interface. In addition, all existing WAN servers and services, such as the remote host, the free network range, the DNS servers, the SNMP network management server, etc. are accessible to both the DOCSIS and WAN networks.

In addition, the DOCSIS configuration file used by CDRouter is user-defined and can either be specified as:

  1. The path to an existing properly formatted and encoded DOCSIS configuration file on disk, OR
  2. A list of DOCSIS TLVs which are embedded directly within CDRouter’s configuration file and encoded by CDRouter automatically at run time

This makes it possible to fully provision and test DOCSIS devices in a closed loop setup with a dedicated CMTS or in an environment utilizing a shared CMTS without requiring external provisioning servers or services. With the DOCSIS add-on, provisioning and testing of DOCSIS devices is easier and provides a more flexible configuration and testing possibilities.

CMTS Support

CDRouter DOCSIS has no specific requirements on the CMTS and is compatible with most commercially available CMTS equipment. When possible, the preferred setup involves using a dedicated CMTS in a bridge configuration with CDRouter’s WAN interface connected directly to the CMTS uplink. This is the least complex setup and requires minimal configuration.

CDRouter DOCSIS can also be used in larger lab environments where one CMTS is shared among different people and devices. Typically in these environments the CMTS or an intermediate router will implement DHCP relay to forward DHCP packets from CMs to specific DHCP servers. CDRouter DOCSIS is compatible with DHCP relay and can be configured as the DHCP server for specific devices when used in a shared environment.

Users that do not currently have a CMTS should contact support@qacafe.com for equipment recommendations and test setup guidance.

CM Provisioning Modes

The DOCSIS 3.0 specification defines four different IP provisioning modes for the CM:

  • IPv4 only
  • IPv6 only
  • Alternate provisioning mode (APM): IPv6 first with failover to IPv4
  • Dual-stack provisioning mode (DPM): IPv4 and IPv6 simultaneously

The IP provisioning mode is a CMTS configuration option that is transmitted periodically by the CMTS to all attached CM via MAC Domain Descriptor (MDD) messages.

CDRouter DOCSIS currently supports provisioning of the CM via IPv4 or IPv6. APM and DPM modes within the CMTS can also be tested and will ensure that the CM fails over properly when IPv4 or IPv6 provisioning is not available.

Support for full dual-stack provisioning of the CM will be added to a future release.

Initial Setup

There are two basic test setups for CDRouter DOCSIS: the simple closed loop setup where a dedicated CMTS is available and configured to bridge all traffic, and the routed setup typically found in a shared lab environment where DHCP relay is used.

Test Setup #1: Dedicated CMTS in Bridge Mode

The simplest test setup for testing DOCSIS devices requires a dedicated CMTS that is connected directly to CDRouter’s WAN interface. CDRouter then connects via Ethernet or wireless to the LAN side of the DUT which connects via coax to the CMTS, as shown in this diagram:

CDRouter DOCSIS bridged test setup

In this setup the CMTS should be configured to bridge all traffic from the DUT to its uplink port; no additional network or routing configuration is required on the CMTS.

Test Setup #2: Shared CMTS in Routed / DHCP Relay Mode

CDRouter DOCSIS can also be used in environments where a single CMTS is shared by many users, as shown in this diagram:

CDRouter DOCSIS routed relay test setup

In these environments a DHCP relay function is typically enabled within the CMTS or an attached router. The relay, in conjunction with a CM provisioning system, ensures that all connected CMs can be fully provisioned and access the WAN. To test a specific device with CDRouter in this setup the DHCP relay must be configured to forward all DHCP requests from the DUT’s CM and eRouter (or attached CPE) to CDRouter’s DOCSIS and WAN DHCP servers, respectively. Provisioning for all other CMs not being tested by CDRouter should be performed by the existing provisioning system.

In addition, static routes must be installed on the CMTS or attached router to ensure that test traffic destined for CDRouter’s various servers and services on the WAN are forwarded to CDRouter’s DOCSIS and WAN interfaces.

Detailed configuration examples for both test setups are provided in the configuration section below.

Start-Up

CDRouter DOCSIS adds an additional step of CM provisioning to the normal CDRouter start-up procedure performed at the beginning of every test run.

When the CDRouter DOCSIS add-on is enabled, CDRouter will start and manage two separate DHCP servers on the WAN. The WAN DHCP server resides within CDRouter’s WAN ISP network and is designed to service the DHCP client within the eRouter or CPE. The second DHCP server is located within the new DOCSIS network and is designed to service the CMs DHCP client.

The two DHCP servers have unique addresses and reside within different networks that are attached to the WAN interface. The two DHCP servers use the contents of the Vendor Class Identifier option (DHCP option 60, or DHCPv6 option 16) to determine if a received request is from a CM or an eRouter / CPE.

A Vendor Class Identifier option that begins with the string docsis, indicates that the requesting client is a CM and the request will be answered by the DOCSIS DHCP server. The DOCSIS DHCP server will provide an address and gateway information to the CM as well as addresses for all other servers required to provision the CM, including:

  • TFTP: for IPv4, the TFTP server information is provided via the DHCP TFTP Server option (option 66) and the Next server IP address field. For IPv6, the TFTP server information is provided via the TFTP Server Addresses suboption (32) of the DHCPv6 Vendor-specific Information option (option 17).

  • Time: for IPv4, the RFC 868 Time server information is provided via the DHCP Time Server option (DHCP option 2). CDRouter’s DOCSIS DHCP server will also include the DHCP Time Offset option (option 4) with a value of 0 in all DHCP messages sent to the CM. For IPv6, the RFC 868 Time server information is provided via the Time Protocol Servers suboption (37) of the DHCPv6 Vendor-specific Information option (option 17). The Time Offset suboption (38) of the DHCPv6 Vendor-specific Information option (option 17) will also be set to a value of 0.

  • Log: for IPv4, the log server information is provided via the DHCP Log Server option (option 7). For IPv6, the log server information is provided via the Syslog Servers suboption (34) of the DHCPv6 Vendor-specific Information option (option 17).

Once the CM has obtained an address, it should contact the learned Time server to obtain a time value. Note that CDRouter’s Time server will provide the system’s current time to the CM when queried. Following time synchronization, the CM should then contact CDRouter’s TFTP server and download its DOCSIS configuration file.

The CM is fully provisioned once the DOCSIS configuration file has been downloaded via TFTP and applied. Once the CM has been successfully provisioned, the DUT’s eRouter, or an attached CPE device, if present, will begin initialization and will interact with CDRouter’s primary WAN network servers and services. If CM provisioning fails during the start-up procedure, the test run will be aborted.

Running

DOCSIS provisioning can be enabled within CDRouter by setting the testvar supportsDocsis to a value of “yes”.

By default provisioning will be provided via IPv4 only. To change the provisioning mode from IPv4 to IPv6, the testvar docsisIpProvisioningMode must be changed to a value of “ipv6-only”.

To test the CM’s SNMP functionality, the SNMP add-on must also be licensed and and properly configured. Please see the CDRouter SNMP User’s Guide for more information on configuring CDRouter for SNMP. Likewise, to perform Nmap scans against the CM interface, the Nmap add-on must be licensed and enabled by setting the testvar supportsNmap to a value of “yes”.

CDRouter DOCSIS includes a number of test modules designed specifically to test the CM interface of a DOCSIS device. These test modules can be run alone or in combination with other CDRouter test modules that target the eRouter or attached CPE to fully test a DOCSIS compliant device. The following table summarizes the different test modules included with CDRouter DOCSIS and any additional add-ons that may be required:

Test Module Interface Required Add-ons
dhcp-docsis.tcl CM DOCSIS
firewall-docsis.tcl CM DOCSIS
nmap-docsis.tcl CM DOCSIS + Nmap
snmp-docsis.tcl CM DOCSIS + SNMP
dhcpv6-docsis.tcl CM DOCSIS + IPv6
firewall-docsis-v6.tcl CM DOCSIS + IPv6
nmap-docsis-v6.tcl CM DOCSIS + Nmap + IPv6
snmp-docsis-v6.tcl CM DOCSIS + SNMP + IPv6

To run only the DOCSIS related test modules from the command-line:

$ cdrouter-cli -addon DOCSIS –trace –pt

For additional test execution options, see the CDRouter CLI Guide.

Configuration

All testvars associated with DOCSIS are located within the CDRouter DOCSIS Add-On section of the CDRouter configuration file.

The DOCSIS add-on can be globally enabled or disabled using the testvar supportsDocsis. Setting this testvar to a value of “yes” will enable CDRouter’s internal CM provisioning system, which will set up a second “DOCSIS” network on the WAN in addition to the main WAN network.

The DOCSIS network is designed to provide connectivity and provisioning services for CMs whereas the main WAN network will provide connectivity for eRouters or other CPE attached to the CM. The DOCSIS network can be configured for either IPv4 or IPv6 operation, based on value of the testvar docsisIpProvisioningMode. The main WAN network can be configured for IPv4, IPv6, or dual-stack operation.

CDRouter’s CM provisioning system consists of the following servers which will be automatically created and managed by CDRouter within the DOCSIS network when DOCSIS is enabled:

  • Default Gateway
  • DHCP server
  • TFTP server
  • Time server
  • Log server

IPv4 Provisioning

When the testvar docsisIpProvisioningMode is set to a value of “ipv4-only”, the DOCSIS network and all CM provisioning services will be accessible via IPv4.

To configure the IPv4 addresses of all servers within the DOCSIS network, please see the IPv4 Provisioning portion of the CDRouter config file.

IPv6 Provisioning

When the testvar docsisIpProvisioningMode is set to a value of “ipv6-only”, the DOCSIS network and all CM provisioning services will be accessible via IPv6.

To configure the IPv6 addresses of all servers within the DOCSIS network, please see the IPv6 Provisioning portion of the CDRouter config file.

CM MAC Filtering

By default, CDRouter’s DOCSIS DHCP and DHCPv6 servers will respond to any CM requests that are received. To filter requests to a single device, the testvar docsisClientMac can be configured and set to the CM’s MAC address. This testvar should always be configured in shared CMTS environments where multiple CMs are present.

Additional Configuration

There are a number of additional configuration options for CDRouter’s DOCSIS DHCP server. Please see the CDRouter configuration file and inline help text for more information.

The DOCSIS CM Configuration File

There are two options for defining the DOCSIS configuration file that is provided by CDRouter to the CM during provisioning.

The first option is to use an existing, user or vendor defined and properly encoded DOCSIS configuration file. Existing DOCSIS config files can be copied to the CDRouter system and used during testing by specifying the full path on disk with the testvar docsisConfigFile.

The second option is to define a DOCSIS configuration file in a CDRouter configuration using the testvar docsisConfig. This testvar allows a human readable DOCSIS configuration file to be embedded within the CDRouter configuration file. The contents are encoded at run time and the resulting file is provided by CDRouter to the CM during provisioning.

The default DOCSIS configuration file used by CDRouter is shown below. Any valid TLV can be used in this configuration file. CDRouter’s default DOCSIS configuration file should be sufficient for provisioning most CMs and is the recommended starting point for DOCSIS testing.

testvar docsisConfig                     {
         Main
         {
             NetworkAccess 1;
             BaselinePrivacy
             {
                     AuthTimeout 10;
                     ReAuthTimeout 10;
                     AuthGraceTime 600;
                     OperTimeout 1;
                     ReKeyTimeout 1;
                     TEKGraceTime 600;
                     AuthRejectTimeout 60;
                     SAMapWaitTimeout 1;
                     SAMapMaxRetries 4;
             }
             MaxCPE 3;
             UsServiceFlow
             {
                     UsServiceFlowRef 2;
                     QosParamSetType 7;
             }
             DsServiceFlow
             {
                     DsServiceFlowRef 1;
                     QosParamSetType 7;
             }
             SNMPv1v2cCoexistenceConfig
             {
                     SNMPv1v2cCommunityName "public";
                     SNMPv1v2cTransportAddressAccess
                     {
                             SNMPv1v2cTransportAddress 0.0.0.0/0;
                             SNMPv1v2cTransportAddressMask 0.0.0.0/0;
                     }
                     SNMPv1v2cAccessViewType 2;
                     SNMPv1v2cAccessViewName "docsisManagerView";
             }
             /* CmMic e07f5ace4d2b69cfd8d65cdeb30f739c; */
             /* CmtsMic 08187b8a159f0fa6021fa95be0be5a59; */
             /*EndOfDataMkr*/
         }
     }

A list of the TLVs that may be defined in the DOCSIS configuration file can be found here. These values map to the common TLV encodings defined in Annex C of the DOCSIS 3.0 MAC and [Upper Layer Protocols Interface Specification

Example DOCSIS configuration files for a number of different scenarios can be found here.

eRouter Configuration

If the DUT includes and integrated eRouter, the CM configuration file should include an additional eRouter section, with at minimum the InitializationMode included. This TLV is particularly important because it controls the IP mode of the eRouter:

InitializationMode TLV Value Description
0 eRouter disabled
1 eRouter IPv4 only
2 eRouter IPv6 only
3 eRouter dual-stack

The eRouter section of the CM configuration file can also be used to configure CWMP, as discussed in the Testing Exercises section below.

A description of all eRouter specific TLVs can be found in the CableLabs eRouter specification.

CM Firewall Configuration

The DOCSIS add-on includes tests for verifying the firewall behavior of the CM interface. These tests are similar to CDRouter’s existing firewall tests, and require information about which ports on the CM interface the user expects to be open, closed, or in stealth mode for both UDP and TCP traffic.

By default all ports are assumed to be in stealth mode. Any UDP and TCP ports that the user expects to be open should be configured using the testvars docsisUdpOpenPorts and docsisTcpOpenPorts, respectively.

Likewise, any UDP and TCP ports that the user expects to be closed should be configured using the testvars docsisUdpClosedPorts and docsisTcpClosedPorts, respectively.

These testvars can be configured with a list of individual ports and port ranges. The special keyword all can be used for the UDP and TCP closed port lists to indicate that the user expects all ports to be actively closed by the CM.

Example #1: Dedicated CMTS in Bridge Mode

The diagram below shows the most basic CDRouter DOCSIS setup where a dedicated CMTS is used in a bridge configuration. In this setup the CMTS uplink port is connected directly to CDRouter’s WAN interface. The CMTS will forward all packets from the CM and eRouter directly to CDRouter’s DOCSIS and WAN ISP networks, respectively.

CDRouter DOCSIS bridged example

This is the least complex setup for CDRouter DOCSIS testing. It is highly controlled and will produce the most repeatable and consistent results for regression testing.

  1. The Blonder Tongue BT- CMTS-3000 CMTS can be purchased and used in conjunction with CDRouter DOCSIS to create a small, self-contained, and simple DOCSIS test environment.

Example #2: Shared CMTS in Routed / DHCP Relay Mode

The diagram below shows how CDRouter DOCSIS can be used in environment which utilizes a shared CMTS. In these environments DHCP relay is typically implemented with the CMTS or within an intermediate router within the shared network.

The existing DHCP relay must be properly configured to ensure that all traffic from the DUT’s CM and eRouter interfaces is forwarded to CDRouter’s DOCSIS and WAN ISP DHCP servers. This typically requires knowledge of the DUT’s CM and eRouter MAC addresses - the DHCP relay can be configured to forward traffic from these MACs to an alternate DHCP server. Likewise, CDRouter’s DOCSIS DHCP and WAN ISP DHCP servers should be configured to process packets from the DUT’s CM and eRouter only using the testvars docsisClientMac and dhcpClientMac, respectively.

CDRouter DOCSIS routed relay example

In addition, static routes must be configured within the shared network to ensure that all test traffic destined for CDRouter’s DOCSIS and DHCP servers is forwarded to CDRouter. Please contact support@qacafe.com for more information.

Testing Exercises

Aside from running each test case included with the CDRouter DOCSIS add-on, a number of other interesting test scenarios are possible with CDRouter. The following testing exercises are recommended.

TR-069 Provisioning via the DOCSIS Configuration File

TR-069 can be enabled on the eRouter from within the DOCSIS configuration.

On systems that have both the CDRouter DOCSIS and TR-069 add-ons, this make it possible to dynamically configure TR-069 at run-time. To enable TR-069 on the eRouter, an eRouter section must be added to the DOCSIS configuration file with a number of additional TR-069 specific TLVs. The following DOCSIS configuration file enables TR-069 within the eRouter using CDRouter’s default ACS configuration:

testvar docsisConfig                     {
         Main
         {
             NetworkAccess 1;
             BaselinePrivacy
             {
                     AuthTimeout 10;
                     ReAuthTimeout 10;
                     AuthGraceTime 600;
                     OperTimeout 1;
                     ReKeyTimeout 1;
                     TEKGraceTime 600;
                     AuthRejectTimeout 60;
                     SAMapWaitTimeout 1;
                     SAMapMaxRetries 4;
             }
             MaxCPE 3;
             UsServiceFlow
             {
                     UsServiceFlowRef 2;
                     QosParamSetType 7;
                     MaxRateSustained 1000000;
             }
             DsServiceFlow
             {
                     DsServiceFlowRef 1;
                     QosParamSetType 7;
                     MaxRateSustained 2000000;
             }
             SNMPv1v2cCoexistenceConfig
             {
                     SNMPv1v2cCommunityName "public";
                     SNMPv1v2cTransportAddressAccess
                     {
                             SNMPv1v2cTransportAddress 0.0.0.0/0;
                             SNMPv1v2cTransportAddressMask 0.0.0.0/0;
                     }
                     SNMPv1v2cAccessViewType 2;
                     SNMPv1v2cAccessViewName "docsisManagerView";
             }
             eRouter
             {
                    InitializationMode 1;
                    TR69ManagementServer
                    {
                            EnableCWMP 1;
                            URL "http://acs.qacafe.com";
                            Username "qacafe";
                            Password "qacafe123";
                            ConnectionRequestUsername "qacafe";
                            ConnectionRequestPassword "qacafe123";
                            ACSOverride 0;
                    }
             }
             /* CmMic e07f5ace4d2b69cfd8d65cdeb30f739c; */
             /* CmtsMic 08187b8a159f0fa6021fa95be0be5a59; */
             /*EndOfDataMkr*/

One way to exercise this is to vary the TR-069 configuration within the DOCSIS configuration file and ensure that the eRouter behaves as expected. For example, TR-069 can be enabled and disabled, the ACS URL can be changed, or the ACS credentials can be modified. In all cases the eRouter should use the values in the DOCSIS config file that it downloaded during CM provisioning.

CM Performance Verification

Using the CDRouter Performance add-on, the maximum upstream and downstream data rates provisioning within the CM can be verified.

Upstream and downstream limits for the CM can be defined within the USServiceFlow and DSServiceFlow portions of the DOCSIS configuration file, respectively, using the MaxRateSustained TLV. For example, to specify a maximum rate of 2Mbps downstream and 1Mbps upstream, the DOCSIS configuration file would contain:

testvar docsisConfig                     {
         Main
         {
             NetworkAccess 1;
             BaselinePrivacy
             {
                     AuthTimeout 10;
                     ReAuthTimeout 10;
                     AuthGraceTime 600;
                     OperTimeout 1;
                     ReKeyTimeout 1;
                     TEKGraceTime 600;
                     AuthRejectTimeout 60;
                     SAMapWaitTimeout 1;
                     SAMapMaxRetries 4;
             }
             MaxCPE 3;
             UsServiceFlow
             {
                     UsServiceFlowRef 2;
                     QosParamSetType 7;
                     MaxRateSustained 1000000;
             }
             DsServiceFlow
             {
                     DsServiceFlowRef 1;
                     QosParamSetType 7;
                     MaxRateSustained 2000000;
             }
             SNMPv1v2cCoexistenceConfig
             {
                     SNMPv1v2cCommunityName "public";
                     SNMPv1v2cTransportAddressAccess
                     {
                             SNMPv1v2cTransportAddress 0.0.0.0/0;
                             SNMPv1v2cTransportAddressMask 0.0.0.0/0;
                     }
                     SNMPv1v2cAccessViewType 2;
                     SNMPv1v2cAccessViewName "docsisManagerView";
             }
             /* CmMic e07f5ace4d2b69cfd8d65cdeb30f739c; */
             /* CmtsMic 08187b8a159f0fa6021fa95be0be5a59; */
             /*EndOfDataMkr*/
         }

Using CDRouter Performance, the 2Mbps / 1Mbps performance limits of the CM can be verified. These performance limits can also be varied to ensure that the CM uses the values that it has been provisioned with.

Vary the MaxCPE TLV

The MaxCPE TLV specifies the number of unique MAC addresses that may forward traffic through the CM. When testing CMs without an integrated eRouter, the value of this TLV can be varied and tested using CDRouter’s scaling test module.

If the MaxCPE TLV is set to a value of 3, no more than three unique MACs should be allowed to forward traffic. By running the scaling tests against the CM (which is acting as a bridge in this case) and specifying a DHCP pool size of four, the fourth client created during the scaling tests should consistently fail to obtain an address while the first three pass. Modifying the DHCP pool to a size of three and re-running the scaling tests should show that all clients are able to obtain an IP address and forward traffic.

Vary the SNMP Configuration via DOCSIS

The SNMP configuraiton of the CM is controlled by the DOCSIS configuation file. A useful exercise is to vary the SNMP configuration within the DOCSIS configuration file and then use the CDRouter SNMP add-on to verify that the provisioned configuration has been applied by the CM.

It’s also possible to use CDRouter’s SNMP scenarios feature to target specific tests at the CM interface.

Caveats

CM Provisioning Over IPv6

To run the CDRouter DOCSIS IPv6 specific test modules the docsisIpProvisioningMode must be set to ipv6-only and the eRouter or attached CPE must also be configured to support IPv6.

eMTA Provisioning

CDRouter DOCSIS does not currently support the provisioning of eMTA devices. Support for eMTA devices may be added to a future release. As a result, all requests from eMTA devices will be ignored.

Provisioning of Multiple Devices

CDRouter’s CM provisioning system is designed to support a single device only. In shared CMTS environments where multiple CMs are present, users are encouraged to define DHCP relay rules for the CM MAC of the DUT that forward only requests from that specific device to CDRouter’s CM DHCP server, or specify the DUT’s CM MAC using the docsisClientMac testvar which will force CDRouter’s CM DHCP server to ignore requests from all other MACs.

DHCP Client ID Behavior

RFC 2131 specified that DHCP servers must not include the client identifier option in DHCPOFFER, DHCPACK or DHCPNAK messages. RFC 6842, which updated RFC 2131, reversed this requirement making it mandatory to include the client identifier option in such messages.

By default CDRouter includes the client identifier option in DHCPOFFER, DHCPACK and DHCPNAK messages as required by RFC 6842. However, some DOCSIS DHCP clients are strict in their handling of the client identifier option and will drop messages that contain it.

The testvar dhcpServerClientIDBehavior can be set to a value of rfc2131 to force CDRouter’s DHCP server to drop back to the behavior defined in RFC 2131 and omit the client identifier option in DHCPOFFER, DHCPACK and DHCPNAK messages.

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