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.


Feature Description - MPLS 01

NE05E and NE08E V300R003C10SPC500

This is NE05E and NE08E V300R003C10SPC500 Feature Description - MPLS
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).
LDP Bit Error Detection

LDP Bit Error Detection

The LDP bit error detection function detects bit errors on LDP interfaces and LDP LSPs and transmits the LSP bit error rate to services carried by LDP LSPs, triggering a primary/backup LSP switchover. This function prevents service transmission quality from deteriorating and improves network reliability.


As mobile services evolve from narrowband voice services to integrated broadband services, providing rich voice, streaming media, and high speed downlink packet access (HSDPA) services, the demand for network bandwidth is rapidly increasing. Meeting the bandwidth demand on traditional bearer networks requires huge investments. Therefore, carriers are in urgent need of an access mode that is low cost, flexible, and highly efficient, which can help them meet the challenges brought by the growth in wideband services. In this context, the all-IP mobile bearer networks are an effective means of dealing with these issues. IP radio access networks (RANs), a type of IP-based mobile bearer network, are increasingly widely used.

IP RANs, however, have more complex reliability requirements than traditional bearer networks when carrying broadband services. Traditional fault detection mechanisms cannot trigger protection switching based on random bit errors. Therefore, bit errors may degrade or even interrupt services on an IP RAN in extreme cases. Bit-error-triggered protection switching can solve this problem.


Bit-error-triggered LDP protection switching has the following benefits:

  • Protects traffic from random bit errors, improving service quality.

  • Enables devices to record bit error events, enabling carriers to quickly locate the nodes or lines with bit errors and take corrective measures.

Related Concepts

LDP interface bit error rate

LDP interface bit error rate is the bit error rate detected by LDP on an interface. A node uses a Link Hello message to report its LDP interface bit error rate to an upstream LDP peer.

LSP bit error rate

LSP bit error rate on a node = LSP bit error rate reported by the downstream LDP peer + the LDP interface bit error rate reported by the downstream LDP peer.


The NE supports single-node and multi-node LDP bit error detection and calculation. When LDP detects an interface bit error on a node along an LSP, the node sends a Link Hello message to notify its upstream LDP peer of the interface bit error rate and a Label Mapping message to notify its upstream LDP peer of the LSP bit error rate. Upon receipt of the notifications, the upstream LDP peer uses the received interface bit error rate as the local LDP interface bit error rate, adds the LDP interface bit error rate to the received LSP bit error rate to obtain the local LSP bit error rate, and sends the interface bit error rate and local LSP bit error rate to its upstream LDP peer. This process repeats until the ingress of the LSP calculates its local LSP bit error rate. Figure 3-16 illustrates the networking for bit-error-triggered LDP protection switching.
Figure 3-16 LDP bit error detection
In Figure 3-16, an LSP is established between PE1 and PE2. If if1 and if3 interfaces both detect bit errors, the bit errors along the LSP to the ingress are advertised and calculated as described by the text in Figure 3-16.

LDP only detects and transmits bit errors, and service switching such as in PW switching or L3VPN route switching occurs on paths carried over LDP.

Updated: 2019-01-14

Document ID: EDOC1100058933

Views: 9097

Downloads: 12

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