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

Reminder

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

upgrade

NE20E-S2 V800R010C10SPC500 Feature Description - Network Reliability 01

This is NE20E-S2 V800R010C10SPC500 Feature Description - Network Reliability
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).
Bit-Error-Triggered Switching for PW

Bit-Error-Triggered Switching for PW

Background

When PW redundancy is configured for L2VPN services, bit-error-triggered switching can be configured. With this function, if bit errors occur, services can switch between the primary and secondary PWs.

Principles

Trigger-LSP bit error detection must be enabled on each node's interfaces. PW redundancy can be configured in either a single segment or multi-segment scenario.

  • Single-segment PW redundancy scenario

    In Figure 9-9, PE1 establishes a primary PW to PE2 and a secondary PW to PE3, which implements PW redundancy. If PE2 detects bit errors, the processing is as follows:

    • PE2 switches traffic destined for PE1 to the path bypass PW -> PE3 -> secondary PW -> PE1 and sends a BFD packet to notify PE1 of the bit errors.

    • Upon receipt of the BFD packet, PE1 switches traffic destined for PE2 to the path secondary PW-> PE3 -> bypass PW -> PE2.

    Traffic between PE1 and PE2 can travel along bit-error-free links.

    Figure 9-9 Bit-error-triggered switching for single-segment PW
  • Multi-segment PW redundancy scenario

    In Figure 9-10, multi-segment PW redundancy is configured. PE1 is dual-homed to two SPEs. If PE2 detects bit errors, the processing is as follows:

    • PE2 switches traffic destined for PE1 to the path bypass PW -> PE3 -> PW2 -> SPE2 -> secondary PW -> PE1 and sends a BFD packet to notify SPE1 of the bit errors.

    • Upon receipt of the BFD packet, SPE1 sends an LDP Notification message to notify PE1 of the bit errors.

    • Upon receipt of the notification, PE1 switches traffic destined for PE2 to the path secondary PW -> SPE2 -> PW2 -> PE3 -> bypass PW-> PE2.

    Traffic between PE1 and PE2 can travel along bit-error-free links. If bit errors occur on a link between PE1 and SPE1, the processing is the same as that in the single-segment PW redundancy scenario.

    Figure 9-10 Bit-error-triggered switching for multi-segment PW

After traffic switches to the secondary PW, and bit errors are removed from the primary PW, traffic switches back to the primary PW based on a configured switchback policy.

NOTE:
If an RSVP-TE tunnel is established for PWs, and bit-error-triggered RSVP-TE tunnel switching is configured, a switchover is preferentially performed between the primary and hot-standby CR-LSPs in the RSVP-TE tunnel. A primary/secondary PW switchover can be triggered only if the primary/hot-standby CR-LSP switchover fails to remove bit errors in either of the following situations:
  • The hot standby function is not configured.
  • Bit errors occur on both the primary and hot-standby CR-LSPs.

Usage Scenario

If L2VPN is used to carry user services and PW redundancy is deployed to ensure reliability, deploy bit-error-triggered switching for PW to minimize the impact of bit errors on user services and improve service quality.

Translation
Download
Updated: 2019-01-02

Document ID: EDOC1100055473

Views: 13421

Downloads: 4

Average rating:
This Document Applies to these Products
Related Version
Related Documents
Share
Previous Next