DEPI Latency Measurement

This document describes how to configure the DEPI latency measurement on the Cisco cBR Series Converged Broadband Router.

Your software release may not support all the features that are documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. The Feature Information Table at the end of this document provides information about the documented features and lists the releases in which each feature is supported.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to http://tools.cisco.com/ITDIT/CFN/. An account on http://www.cisco.com/ is not required.

Hardware Compatibility Matrix for Cisco Remote PHY Device


Note
Unless otherwise specified, the hardware components introduced in a given Cisco Remote PHY Device Software Release are supported in all subsequent releases.
Table 1. Hardware Compatibility Matrix for the Cisco Remote PHY Device

Cisco HFC Platform

Remote PHY Device

Cisco GS7000 Super High Output Node

Cisco 1x2 / Compact Shelf RPD Software 2.1 and Later Releases

Cisco GS7000 Super High Output Intelligent Node (iNode)

Cisco 1x2 / Compact Shelf RPD Software 4.1 and Later Releases

Cisco Intelligent Remote PHY Device 1x2

  • PID—iRPD-1X2=

  • PID—iRPD-1X2-PKEY=

Note
The -PKEY suffix in the PID indicates units that enable the SCTE-55-2 Out-of-Band protocol support.

Information about DEPI Latency Measurement

The DEPI Latency Measurement (DLM) packet is a specific type of data packet used for measuring the network latency between the CCAP core and the RPD. There are two types of DLM packets, ingress DLM packet and egress DLM packet. The ingress DLM measures the latency between the CCAP core and the ingress point in the RPD, and the egress DLM measures the latency between the CCAP core and the egress point of the RPD. For now, only the ingress DLM is supported. Egress DLM will be supported in the future if required.

How to Configure DLM

This section describes how to configure DLM on Cisco cBR-8.

Configuring DLM

To configure DLM, complete the following procedure. DLM is disabled by default, only enabled when configured. 

configure terminal 
cable rpd name 
core-interface interface_name 
network-delay dlm interval_in_seconds

Verifying DLM Configuration

To verify the DLM configuration, use the show cable rpd dlm command as shown in the example below: 

Router# show cable rpd 0000.bbaa.0002 dlm 
Load for five secs: 4%/1%; one minute: 4%; five minutes: 4%
Time source is NTP, 13:12:36.253 CST Sun Jan 1 2017
DEPI Latency Measurement (ticks) for 0000.bbaa.0002
 Last Average DLM:              4993
 Average DLM (last 10 samples): 4990
 Max DLM since system on:       5199
 Min DLM since system on:       4800
 Sample #     Latency (usecs)
 x------------x------------
 0            491
 1            496
 2            485
 3            492
 4            499
 5            505
 6            477
 7            474
 8            478
 9            471

The table below shows descriptions for the fields displayed by this command:

Table 2. show cable rpd dlm Field Descriptions

Field

Description

Last Average DLM

It means the last time average DLM (AD). At first, the Last Average DLM (LAD) is always 0, when the absolute value of (LAD - AD) exceeds or equal to 75us, LAD will be updated to be the value of AD, MAP advance triggered to update, AD will keep updating with the last (latest) 10 samples.

Example: DLM Configuration

The following example shows how to configure DLM: 

Router# configure terminal
Router(config)#cable rpd 1
Router(config-rpd)#core-interface tenGigabitEthernet 3/1/0
Router(config-rpd-core)#network-delay dlm 10

Feature Information for DLM

Use Cisco Feature Navigator to find information about the platform support and software image support. Cisco Feature Navigator enables you to determine which software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to the https://cfnng.cisco.com/ link. An account on the Cisco.com page is not required.


Note

The following table lists the software release in which a given feature is introduced. Unless noted otherwise, subsequent releases of that software release train also support that feature.

Table 3. Feature Information for DLM

Feature Name

Feature Information

DEPI Latency Measurement

Cisco 1x2 / Compact Shelf RPD Software 3.1

This feature was integrated into the Cisco Remote PHY Device.