Overview of LSDP

Definition

The Link Status Detection Protocol (LSDP) detects link connectivity and sets interface status to Up or Down based on the link status.

Purpose

The Ethernet does not have a link negotiation or detection mechanism. If an interface on a link is Down or a fiber encounters a unidirectional communication failure, the devices on two ends of the link or fiber cannot detect the fault. As a result, the devices consider that the related interfaces are Up and still forwards packets to the failure link, causing the packets to be discarded.

To improve service quality, the devices on the Ethernet must be able to:

• Detect link connectivity.
• Take actions based on link the status.

To meet the preceding requirements, the devices must use dedicated probe and have association mechanisms configured. This increases investment on network devices. Using Huawei LSDP, the devices do not need to use dedicated probe or association mechanisms, which reduce costs. LSDP can detect link connectivity and accurately take actions based on the link status. When a link fails, LSDP sets the interface status to Down, making the route to this interface and related forwarding entries invalid. When detecting that the link is recovered, LSDP changes the interface status to Up, and the interface can process services.