No relevant resource is found in the selected language.

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies. Read our privacy policy>Search


To have a better experience, please upgrade your IE browser.


Configuration Guide - Interface Management

CloudEngine 12800 and 12800E V200R003C00

This document describes the interface management configuration, including basic interface configuration, Ethernet interface configuration, and logical interface configuration.

Rate and give feedback:
Huawei uses machine translation combined with human proofreading to translate this document to different languages in order to help you better understand the content of this document. Note: Even the most advanced machine translation cannot match the quality of professional translators. Huawei shall not bear any responsibility for translation accuracy and it is recommended that you refer to the English document (a link for which has been provided).
Configuring VCT

Configuring VCT


Virtual cable test (VCT) technology uses time domain reflectometry (TDR) to detect the cable status. When a pulse is transmitted to the end of a cable or a failure point in the cable, some pulse energies are reflected to the transmit end. The VCT algorithm measures the time spent on transmitting pulses over cables, reaching the failure point, and returning the pulses. The measured time is converted to the distance.

As shown in Figure 2-7, GE1/0/1 on SwitchA connects to GE1/0/2 on SwitchB with a network cable. There is a failure point in the network cable. After VCT is configured on GE1/0/1, the system generates pulse signals. After the pulse signals reach the failure point, some energies are reflected to the transmit end. In this example, the distance between SwitchA and the failure point is L, and the period from sending pulse signals to receiving reflected pulse signals is T, the transmission rate of pulse signals in the cable is V. The formula used to calculate the distance between the failure point and GE1/0/1 is as follows:

L = (V x T)/2

Figure 2-7 VCT

VCT can detect the fault type of a network cable and identify failure points to help locate network cable faults.


  1. Run system-view

    The system view is displayed.

  2. Run interface interface-type interface-number

    The interface view is displayed.

  3. Run virtual-cable-test

    The VCT function is configured.

    • Electrical interfaces and GE or 10GE optical interfaces connected to an SFP-GE electrical interface module support the setting.
    • When GE or 10GE optical interfaces use SFP-GE copper modules and the interfaces on the two ends of the link are both Up, the test result may be not accurate and is only for reference.
    • The test result is only for reference and may be inaccurate for cables from some vendors.
    • Running the virtual-cable-test command may affect services on the interface in a short period of time.
    • Before configuring VCT, shut down the remote interface or remove the network cable between the local and remote interfaces. Otherwise, signals from the remote interface may make the test result inaccurate.

Verifying the Configuration

Run the display interface interface-type interface-number virtual-cable-test command to check the latest cable test result on an Ethernet interface.

Updated: 2019-05-05

Document ID: EDOC1100004195

Views: 19021

Downloads: 37

Average rating:
This Document Applies to these Products

Related Version

Related Documents

Previous Next