Overview of SEP

Definition

The Smart Ethernet Protection (SEP) protocol is a ring network protocol specially used for the Ethernet link layer. A SEP segment consists of interconnected Layer 2 switching devices configured with the same SEP segment ID and control VLAN ID. A SEP segment is the basic unit of SEP.

Purpose

SEP blocks redundant links to prevent logical loops on a ring network. Redundant links are used on an Ethernet switching network to provide link backup and enhance network reliability. However, the use of redundant links may produce loops, causing broadcast storms and rendering the MAC address table unstable. As a result, communication quality deteriorates, and services may even be interrupted. Huawei switches support the following ring network protocols:

STP/RSTP/MSTP

STP, RSTP, and MSTP are standard protocols for breaking loops on Ethernet networks. Networks running these protocols converge slowly, failing to meet the transmission requirements of some real-time services. The convergence time is affected by the network topology. Huawei devices running STP, RSTP, or MSTP can communicate with non-Huawei devices.
RRPP

RRPP is a fast convergence Huawei proprietary protocol. RRPP requires a physical topology to be divided into logical topologies so that major rings and sub-rings can be differentiated. Therefore, RRPP does not apply to complex networks. A Huawei device running RRPP cannot communicate with any non-Huawei device.

Huawei developed SEP to overcome the disadvantages of the preceding ring network protocols. SEP has the following advantages:

Works on diverse complex networks and supports all topologies and network topology queries. A network running SEP can connect to a network running STP, RSTP, MSTP, or RRPP.

Helps quickly locate blocked interfaces through network topology display. When a fault occurs, SEP can quickly locate the fault, improving network maintainability.
Implements traffic load balancing by selectively blocking interfaces.
Improves network stability by preventing traffic from switching back after link recovery.