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.
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 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.
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
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|
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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.
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# configure terminal
Router(config)# cable clock dti-server-type polylink
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
|
|
|
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# 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# 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
|
|
|
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# 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
|
|
|
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:
DTI Client status: TCC 13
Client clock type : ITU type 1
Client firmware version : 7
Client timestamp : 657519453
Client phase correction : 65535
Client normal time : 65535
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
DTI Client Port 1 Status:
-------------------------
-- Connected server information ---
Server status : Active free-run
Root Server clock type : ITU type 3
Root Server source : none
Client Performance Stable : yes
Client Cable advance Valid : yes
DTI Client Port 2 Status:
-------------------------
DTI Client status: TCC 14
Client clock type : ITU type 1
Client firmware version : 7
Client timestamp : 672169320
Client phase correction : 65535
Client normal time : 65535
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
DTI Client Port 1 Status:
-------------------------
DTI Client Port 2 Status:
-------------------------
-- Connected server information ---
Server status : Active free-run
Root Server clock type : ITU type 3
Root Server source : none
Client Performance Stable : yes
Client Cable advance Valid : yes
Router# show cable clock 13 client 1
DTI Client Port 1 Status:
-------------------------
Table 1 describes the significant fields shown in the display.
Table 1 show cable clock client Field Descriptions
|
|
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
Root Server clock type : ITU type 3
Root Server source : none
Client Performance Stable : yes
Client Cable advance Valid : yes
Table 2 describes the significant fields shown in the display.
Table 2 show cable clock server Field Descriptions
|
|
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
|
|
|
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
|
|
|
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.
Standards
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CM-SP-DTI-I05-081209 |
Data-Over-Cable Service Interface Specifications Modular Headend Architecture DOCSIS Timing Interface Specification. |
MIBs
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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
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No new or modified RFCs are supported by this feature, and support for existing RFCs has not been modified by this feature. |
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Technical Assistance
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http://www.cisco.com/techsupport |
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
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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
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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.