ISIS Protocol Bit Error Detection in Layer 2 Networks
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Solution Overview
Problem
The existing Bidirectional Forwarding Detection (BFD) mechanism, based on layer 3 UDP protocol, cannot be applied to layer 2 networks, posing a challenge for bit error information transfer in scenarios like data center networks using the TRILL protocol.
Innovation Solution
Extending the ISIS protocol to carry bit error information within ISIS packets, allowing for bit error detection and notification across layer 2 networks, enabling traffic adjustments to avoid data loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the BFD mechanism is used for bit error detection, then fast link fault detection capability is achieved, but the mechanism cannot be applied to layer 2 networks
Solution Approach 1:
The patent extends the ISIS protocol to carry bit error information, making it a multi-functional protocol that can operate in both layer 2 and layer 3 networks. The ISIS protocol is enhanced with new TLV fields to transport bit error status, allowing universal application across different network layers without requiring separate mechanisms like BFD for layer 2.
2Speed
If the BFD protocol is used, then millisecond-level detection speed is achieved, but dependency on IP address limits its applicability
Solution Approach 1:
The patent extracts the bit error detection and notification functionality from the layer 3 BFD protocol and integrates it into the layer 2 ISIS protocol. By removing the dependency on IP addresses and UDP, the solution achieves fast detection capability while eliminating the protocol dependency that limited BFD's applicability to layer 2 networks.
3Device complexity
If bit error information is not transferred, then protocol simplicity is maintained, but traffic loss occurs due to undetected errors
Solution Approach 1:
The patent introduces an intermediary mechanism where ISIS packets carry bit error information as TLV fields. This intermediary approach allows bit error status to be transported alongside routing information without requiring a completely new protocol, maintaining relative simplicity while enabling error detection and prevention of traffic loss through cost value adjustment.
Data Source
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AI summary
A bit error information transfer method, a network device, and a communications system are provided, so as to resolve a problem that an existing BFD mechanism cannot be applied to a layer 2 network and cannot be widely applied. In some feasible implementation manners of the present invention, the method includes: detecting, by a second network device, whether a bit error occurs on a first unidirectional link from a first network device to the second network device; when detecting that a bit error occurs on the first unidirectional link, generating an ISIS packet including bit error information, where the bit error information is used to indicate that the bit error occurs on the first unidirectional link; and sending the ISIS packet to the first network device.