DTI Client

 

First Published: March 20, 2009

Last Updated: September 18, 2017

 

The DOCSIS Timing Interface (DTI) Client running on the Cisco RF Gateway 10 (RFGW-10) Universal Edge Quadrature Amplitude Modulation (UEQAM) collects DTI server master clock, DOCSIS timestamp, and Time of Day information from the DTI Server. It interfaces with the DTI Server to provide Time, Frequency and Management interfaces to the Modular Cable Modem Termination System (M-CMTS) device.

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the “Feature Information for DTI Client” section.

Use Cisco Feature Navigator to find information about platform support and Cisco IOS, Catalyst OS, and Cisco IOS XE software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.

Contents

Prerequisites for DTI Client

  • One active Timing, Communication, and Control (TCC) card.
  • The DTI server and client must have an RJ-45 (female) connector for each DTI link.

Information About DTI Client

The DTI protocol is supported by two terminated entities:

  • DTI Server
  • DTI Client

DTI server and client functional entities are part of the M-CMTS architecture. The DOCSIS Client function is structured to permit a low cost client clock function within all EQAMs, upstream receivers, and M-CMTS CORE entities.

Effective with Cisco IOS-XE Release 3.4.1SQ, the following two DTI server types are available. By default, symmetricom is configured.

  • Symmetricom
  • Polylink

The DTI resides in the TCC as a client on the Cisco RFGW-10 UEQAM to communicate with the DTI server to perform and maintain the frequency and time synchronization for the Cisco RFGW-10 DOCSIS.

Figure 1 shows the DTI architecture.

Figure 1 DTI Architecture

 

The DTI clock runs in one of the following two modes:

Normal Mode

Indicates that the DTI clock is stable, has locked on to the timing reference (DTI server), and is compliant with the appropriate clock standard. The DTI client is in communication with the DTI server. By default, the clock runs in the normal mode.

Free-run Mode

Indicates that the DTI clock is operating with output frequency that is not influenced by a client or the DTI server but by the internal clock on the TCC card. Free-run mode provides the needed stability when external reference is lost or not equipped. Free-run mode ends when the clock output is influenced by an external reference or the process to achieve lock to an external reference.

How to Configure and Display the DTI Client

This section describes how to configure, clear and display the DTI Client in the Cisco RFGW-10 UEQAM.

Changing the DTI Server Type

This procedure describes how to change the DTI server type on the Cisco RFGW-10.

By default, the Symmetricom DTI server type is configured on the Cisco RFGW-10. If you want to change the server type, perform this procedure.

Note When you change the DTI server type, the respective server type image is downloaded from the supervisor to the TCC flash and the TCC slot is reset to reflect the change, due to this all the line cards are reset.

Restrictions

After you change the DTI server type, all the line cards in the chassis will be reset and may result in service outage. So this procedure should be performed only in the maintenance window.

SUMMARY STEPS

1. enable

2. configure terminal

3. cable clock dti-server-type

4. exit

DETAILED STEPS

Command or Action
Purpose

Step 1

enable

 

Router> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

 

Router# configure terminal

Enters global configuration mode.

Step 3

cable clock dti-server-type

 

Router(config)# cable clock dti-server-type polylink

Sets the DTI server type on the Cisco RFGW-10.

Cisco RFGW-10 supports the following DTI server types.

  • symmetricom
  • polylink

By default, the symmetricom DTI server type is configured on the Cisco RFGW-10.

After you change the server type, you will be prompted to restart all the TCC cards. Enter “y” to change the DTI server type.

Note If you restart the TCC cards, all the line cards in the chassis will be reset and may result in service outage.

Step 4

exit

 

Router(config)# exit

Exits global configuration mode.

Examples

Following example shows how to set the DTI server type:

Router> enable
Router# configure terminal
Router(config)# cable clock dti-server-type polylink
Router(config)# exit

 

Setting the Clock Mode

This procedure describes how to set the clock mode.

Restrictions

The valid slots for the TCC card are slots 13 and 14.

SUMMARY STEPS

1. enable

2. configure terminal

3. [no] cable clock slot free-run

DETAILED STEPS

Command or Action
Purpose

Step 1

enable

 

Router> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

 

Router# configure terminal

Enters global configuration mode.

Step 3

[no] cable clock slot free-run

 

Router(config)# cable clock 13 free-run

Sets the clock in free-run mode.

By default the free-run mode is not enabled.

To disable the clock from free-run mode, use the no form of this command.

The valid slots are 13 and 14.

Examples

Following example shows how to set the TCC card in slot 13 in free-run mode:

Router> enable
Router# configure terminal
Router(config)# cable clock 13 free-run
 

Following example shows how to disable the free-run mode of the TCC card in slot 13:

Router> enable
Router# configure terminal
Router(config)# no cable clock 13 free-run

Clearing the Clock Counter Information

This procedure describes how to clear the clock counter information in the Cisco RFGW-10 UEQAM.

SUMMARY STEPS

1. enable

2. clear cable clock slot counters

DETAILED STEPS

Command or Action
Purpose

Step 1

enable

 

Router> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

clear cable clock slot counters

 

Router# clear cable clock 13 counters

Clears the client transition and port switch counters.

Examples

Following example shows how to clear the counters on the TCC card in slot 13 on the Cisco RFGW-10:

Router> enable
Router# clear cable clock 13 counters
Router# show cable clock 13 counters
TCC Card 13 DTI counters:
-------------------------
Client Normal time : 0x01B5
Client Holdover time : 0x0000
Client Phase Correction : 65535
Client Freq Correction : 63210
Client EFC Correction : 60649
Client transition count t3 : 0
Client transition count t4 : 0
Client transition count t6 : 0
Client transition count t7 : 0
Client port switch count : 0

Displaying the DTI Client and Server Information

This procedure describes how to display TCC DTI client and server statistic counts and path traceability information in the Cisco RFGW-10 UEQAM.

SUMMARY STEPS

1. enable

2. show cable clock [slot] {client port id | server port id | counters}

DETAILED STEPS

Command or Action
Purpose

Step 1

enable

 

Router> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

show cable clock [slot] {client port id | server port id | counters}

 

Router# show cable clock 13 counters

Displays the cable clock information.

slot: Valid TCC slots are 13 and 14.

client port id: Specifies the DTI client port ID. Valid port values are 1 and 2.

server port id: Specifies the DTI server port ID. Valid port values are 1 and 2.

counters: Specifies the DTI client counters.

Examples

The following example shows how to display the TCC DTI client and server statistic counts and path traceability information:

Router# show cable clock
DTI Client status: TCC 13
-----------------
Client status : normal
Client clock type : ITU type 1
Client firmware version : 7
Client dti version : 0
Client timestamp : 657519453
Client phase correction : 65535
Client normal time : 65535
Client holdover time : 0
Client transition t3 count : 0
Client transition t4 count : 1
Client transition t6 count : 0
Client transition t7 count : 0
Client port switch count : 1
Client Integral Frequency Term : 64518
Client EFC Value : 63282
DTI Client Port 1 Status:
-------------------------
Port Status : Active
Signal detected : yes
CRC error count : 2
Frame error rate : < 2%
Cable advance : 2560
-- Connected server information ---
Server status : Active free-run
Root Server clock type : ITU type 3
Root Server source : none
Server Type : Root
Client Performance Stable : yes
Client Cable advance Valid : yes
DTI Client Port 2 Status:
-------------------------
Port Status : Inactive
Signal detected : no
CRC error count : 66
Frame error rate : > 5%
Cable advance : 0
DTI Client status: TCC 14
-----------------
Client status : normal
Client clock type : ITU type 1
Client firmware version : 7
Client dti version : 0
Client timestamp : 672169320
Client phase correction : 65535
Client normal time : 65535
Client holdover time : 0
Client transition t3 count : 0
Client transition t4 count : 1
Client transition t6 count : 0
Client transition t7 count : 0
Client port switch count : 1
Client Integral Frequency Term : 64760
Client EFC Value : 63832
DTI Client Port 1 Status:
-------------------------
Port Status : Inactive
Signal detected : no
CRC error count : 26
Frame error rate : > 5%
Cable advance : 0
DTI Client Port 2 Status:
-------------------------
Port Status : Active
Signal detected : yes
CRC error count : 2
Frame error rate : < 2%
Cable advance : 1792
-- Connected server information ---
Server status : Active free-run
Root Server clock type : ITU type 3
Root Server source : none
Server Type : Root
Client Performance Stable : yes
Client Cable advance Valid : yes
 
Router# show cable clock 13 client 1
DTI Client Port 1 Status:
-------------------------
Port Status : Inactive
Signal detected : no
CRC error count : 63006
Frame error rate : > 5%
Cable advance : 0x0000
 

Table 1 describes the significant fields shown in the display.

Table 1 show cable clock client Field Descriptions

Field
Description

Port status

Indicates the current status of the DTI port on the TCC card.

Signal detected

Indicates whether the DTI signal was detected.

CRC error count

The number of cyclic redundancy check (CRC) errors. It can indicate intermittent upstream, laser clipping, or common-path distortion.
Router# show cable clock 13 server 2
TCC Card 13 port 2 DTI Server status:
--------------------------------------
Server signal detected : yes
Server status : free-run
Root Server clock type : ITU type 3
Root Server source : none
Server Type : Root
Client Performance Stable : yes
Client Cable advance Valid : yes
TOD Setting Mode : Short
TOD gpssec : 902825745
TOD leap seconds : 14
 

Table 2 describes the significant fields shown in the display.

Table 2 show cable clock server Field Descriptions

Field
Description

Server signal detected

Indicates whether the server is detected or not.

Server status

Indicates the state in which the server is functioning. The states are Warm-up, Free-run state, Fast mode, Normal, Holdover, or Bridge mode.

Root server source

The server source like internal, external or GPS.

Root server clock type

The clock types are 1, 2, 3 or ITU Stratum 3 or DTI Min. clock.

TOD setting mode

Time setting mode (user time, NTP, GPS). The output can be in two formats, short or verbose based on the TOD message provided by the DTI server.
Router# show cable clock 13 counters
TCC Card 13 DTI counters:
-------------------------
Client Normal time : 0x1EB6
Client Holdover time : 0x0000
Client Phase Correction : 0
Client Freq Correction : 63213
Client EFC Correction : 61039
Client transition count t3 : 0
Client transition count t4 : 1
Client transition count t6 : 0
Client transition count t7 : 0
Client port switch count : 1

Enabling Traps for DTI Server State Change

You can enable trap notifications when there is a change in DTI server state.

DETAILED STEPS

Command or Action
Purpose

Step 1

enable

 

RFGW-10> enable

Enables privileged EXEC mode. Enter your password if prompted.

Step 2

configure terminal

 

RFGW-10# configure terminal

Enters global configuration mode.

Step 3

snmp-server enable traps dti server

 

RFGW-10(config)# snmp-server enable traps dti server

Enables traps for receiving notifications on an NMS (network management system) when there is change in DTI server state.

Enabling Traps for DTI Client State Change

You can enable trap notifications when there is a change in DTI client state.

DETAILED STEPS

Command or Action
Purpose

Step 1

enable

 

RFGW-10> enable

Enables privileged EXEC mode. Enter your password if prompted.

Step 2

configure terminal

 

RFGW-10# configure terminal

Enters global configuration mode.

Step 3

snmp-server enable traps dti client

 

RFGW-10(config)# snmp-server enable traps dti client

Enables traps for receiving notifications on an NMS (network management system) when there is change in DTI client state.

Additional References

The following sections provide references related to the DTI Client feature.

Related Documents

Related Topic
Document Title

Cisco RFGW-10 commands

Cisco RF Gateway 10 Command Reference http://www.cisco.com/en/US/docs/cable/rf_gateway/command/reference/RFGW-10_Book.html

New Software Features in Cisco IOS Release 12.2SQ

Cisco RF Gateway 10 Software Feature and Configuration Guide

http://www.cisco.com/en/US/docs/cable/rf_gateway/feature/guide/rfgw_scg.html

Standards

Standard
Title

CM-SP-DTI-I05-081209

Data-Over-Cable Service Interface Specifications Modular Headend Architecture DOCSIS Timing Interface Specification.

MIBs

MIB
MIBs Link

DTI-MIB

To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:

http://www.cisco.com/go/mibs

RFCs

RFC
Title

No new or modified RFCs are supported by this feature, and support for existing RFCs has not been modified by this feature.

—

Technical Assistance

Description
Link

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Access to most tools on the Cisco Support website requires a Cisco.com user ID and password.

http://www.cisco.com/techsupport

Command Reference

The following commands are introduced or modified in the feature or features documented in this module. For information about these commands, see the Cisco RF Gateway 10 Command Reference at http://www.cisco.com/en/US/docs/cable/rf_gateway/command/reference/RFGW-10_Book.html. For information about all Cisco IOS commands, use the Command Lookup Tool at http://tools.cisco.com/Support/CLILookup or the Cisco IOS Master Command List, All Releases, at http://www.cisco.com/en/US/docs/ios/mcl/allreleasemcl/all_book.html.

  • [no] cable clock port_id free-run
  • clear cable clock slot counters
  • show cable clock [slot] {client port id | server port id | counters}

Feature Information for DTI Client

Table 3 lists the release history for this feature.

Not all commands may be available in your Cisco IOS software release. For release information about a specific command, see the command reference documentation.

Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which Cisco IOS, Catalyst OS, and Cisco IOS XE software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.

Note Table 3 lists only the Cisco IOS software release that introduced support for a given feature in a given Cisco IOS software release train. Unless noted otherwise, subsequent releases of that Cisco IOS software release train also support that feature.

 

Table 3 Feature Information for DTI Client

Feature Name
Releases
Feature Information

DTI Client

12.2(44)SQ

This feature was introduced in the Cisco IOS Release 12.2(44)SQ to support the Cisco RF Gateway 10.

The following commands were introduced or modified:

  • [no] cable clock port_id free-run
  • clear cable clock slot counters
  • show cable clock [slot] {client port id | server port id | counters}

Support for Polylink and Symmetricom DTI servers

Cisco IOS-XE Release 3.4.1SQ

This feature was introduced in the Cisco IOS-XE Release 3.4.1SQ to support both Symmetricom and Polylink DTI server types.

The following commands were introduced:

  • clear cable clock slot counters

Glossary

CRC—Cyclic Redundancy Check

DOCSIS—Data Over Cable Service Interface Specifications

DTI—DOCSIS Timing Interface

DTS—DOCSIS Time Stamp

GPS—Global Positioning System

MPEG-TS—Motion Picture Experts Group Transport Stream

PHY—Physical Layer. Used to refer to the downstream QAM transmitters and the upstream burst demodulators (receiver).

TOD—Time of Day. Provides time in binary format and optionally in ASCII format.

UEQAM—Universal Edge Quadrature Amplitude Modulation. A network element, which receives MPEG-TS frames over a network interface such as Ethernet, and modulates them onto QAM carriers for use on an HFC plant.

Cisco and the Cisco logo are trademarks or registered trademarks of Cisco and/or its affiliates in the U.S. and other countries. To view a list of Cisco trademarks, go to this URL: www.cisco.com/go/trademarks. Third-party trademarks mentioned are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (1721R)

Any Internet Protocol (IP) addresses used in this document are not intended to be actual addresses. Any examples, command display output, and figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses in illustrative content is unintentional and coincidental.

© 2009 Cisco Systems, Inc. All rights reserved.