Inter-AS Packet Forwarding With Flexible Algorithm Identification
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Solution Overview
Problem
In a segment routing network, when devices from different autonomous systems (AS domains) communicate, the identification information of flexible algorithms is lost, leading to a lack of flexibility in network deployment.
Innovation Solution
A method where border devices in one AS domain actively obtain and send the identification information of a target flexible algorithm to devices in another AS domain using address prefixes and TLVs, ensuring packets are forwarded through paths corresponding to the target flexible algorithm.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If flexible algorithm identification information is advertised within a single AS domain, then network deployment flexibility is improved for intra-domain devices, but inter-domain communication flexibility deteriorates because the information cannot be received by devices in different AS domains
Solution Approach 1:
The patent segments the address prefix information into two parts: a first address prefix for routing and a second address prefix for flexible algorithm identification. This segmentation allows the flexible algorithm information to be separately transmitted and preserved across AS domain boundaries, preventing information loss while maintaining routing functionality.
Solution Approach 2:
The patent introduces a border device as an intermediary between AS domains. This border device receives routing information from devices in other AS domains, extracts and preserves the flexible algorithm identification information, and forwards it to the appropriate devices within the local AS domain. This intermediary mechanism enables inter-domain information transfer while maintaining intra-domain flexibility.
2Adaptability or versatility
If flexible algorithm information is propagated throughout the entire network, then all devices can access flexible routing paths, but information loss occurs at AS domain boundaries where the propagation is blocked
Solution Approach 1:
The patent applies preliminary action by having the border device perform extraction and preservation of flexible algorithm identification information before the information is lost at the AS domain boundary. The border device proactively processes the routing information, separates the flexible algorithm components, and ensures they are transmitted to the correct destination, preventing the information loss that would otherwise occur during standard propagation.
Solution Approach 2:
The border device serves as an intermediary that captures flexible algorithm identification information at the AS domain boundary, preventing its loss. This intermediary mechanism allows the information to be preserved and re-injected into the appropriate AS domain, maintaining flexible routing capability without requiring end-to-end propagation through all AS domains.
3Ease of operation
If address prefixes are used for routing between AS domains, then inter-domain packet forwarding is enabled, but flexible algorithm identification information is lost in the process
Solution Approach 1:
The patent segments the address prefix into a first address prefix for inter-domain routing and a second address prefix for flexible algorithm identification. This segmentation allows the routing function to operate using the first address prefix while the second address prefix preserves the flexible algorithm information, eliminating the information loss that occurs when only a single address prefix is used.
Solution Approach 2:
The border device acts as an intermediary that processes address prefix information during inter-domain packet forwarding. It extracts the flexible algorithm identification information from the address prefix, preserves it separately, and ensures it reaches the destination device. This intermediary process enables inter-domain forwarding to function while preventing the loss of flexible algorithm information.
Data Source
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AI summary
This application discloses a packet sending method, apparatus, and system, and a storage medium, and relates to the communication field. The method includes: A first device receives a first packet, where the first packet includes a first address prefix, the first device is a border device in a first AS domain, the first address prefix is obtained based on an address prefix advertised by a second device, the second device is located in a second AS domain, the first AS domain is different from the second AS domain, and the first address prefix is used to send a packet to the second device. The first device obtains a second address prefix and identification information of a target flexible algorithm based on the first address prefix, where the second address prefix is used to send a packet to the second device. The first device sends a second packet to a device in the first AS domain, where the second packet includes the second address prefix and the identification information of the target flexible algorithm, so that the device in the first AS domain forwards, through a path corresponding to the target flexible algorithm, a packet that matches the second address prefix. This application can improve flexibility of network deployment.