Time Domain Reflectometry Cable Diagnostics; Licensing Requirements - Cisco 7206 - VXR Router Configuration Manual

Licensing Requirements

S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m
If you delete a specific configuration for a specified range of interfaces using the interface configuration
mode, that configuration is also deleted from the port profile for that range of interfaces only. For
example, if you have a channel group inside a port profile and you are in the interface configuration mode
and you delete that port channel, the specified port channel is also deleted from the port profile as well.
Just as in the device, you can enter a configuration for an object in port profiles without that object being
applied to interfaces yet. For example, you can configure a virtual routing and forward instance (VRF)
without it being applied to the system. If you then delete that VRF and attendant configurations from the
port profile, the system is unaffected.
After you inherit a port profile on an interface or range of interfaces and you delete a specific
configuration value, that port-profile configuration will not be operative on the specified interfaces.
If you attempt to apply a port profile to the wrong type of interface, the system returns an error.
When you attempt to enable, inherit, or modify a port profile, the system creates a checkpoint. If the
port-profile configuration fails, the system rolls back to the prior configuration and returns an error. A
port profile is never only partially applied.

Time Domain Reflectometry Cable Diagnostics

Beginning with Cisco NX-OS Release 5.0(2) for the Cisco Nexus 7000 Series devices and the
introduction of the latest generation of line cards, you can perform cable diagnostics without the use of
expensive third party equipment. With the cable diagnostic capabilities embedded directly in the line
cards, you no longer need to unplug cables and connect cable testers to diagnose a link fault. Each port
on the line card can independently detect cabling issues and report them to the switch software using a
new technology called Time Domain Reflectometry (TDR).
TDR is a technique used to analyze a conductor by transmitting a pulsed waveform signal into it then
examining the polarity, amplitude, and round trip time of the reflected waveform.
By estimating the speed of propagation of the signal in the cable and by measuring the time it takes for
its reflection to travel back to the source, it is possible to measure the distance to the reflecting point.
Also, by comparing the polarity and amplitude of the original pulse with its reflection it is possible to
distinguish between different types of faults, for example, open or shorted pairs.
Being able to remotely diagnose a cable failure, you can now identify the root cause of a problem more
quickly and more effectively, providing your users with a prompt response to connectivity issues.
Licensing Requirements
The following table shows the licensing requirements for this feature:
Product License Requirement
Cisco NX-OS The basic interface parameters require no license. Any feature not included in a license package is bundled
with the Cisco NX-OS system images and is provided at no extra charge to you. For a complete explanation
of the Cisco NX-OS licensing scheme, see the Cisco NX-OS Licensing Guide.
Note Using VDCs requires an Advanced Services license.
Cisco Nexus 7000 Series NX-OS Interfaces Configuration Guide, Release 5.x
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Chapter 2 Configuring Basic Interface Parameters
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