Service Forwarding Entity SFC Header Re-association
Solution Overview
Problem
Legacy Service Processing Entities (SPEs) cannot re-associate Service Function Chain (SFC) headers with processed packets, leading to abnormal interruptions in service function chains due to the loss of SFC headers during packet processing.
Innovation Solution
A method for encapsulating service routing packets involves temporarily storing the correspondence between SFC headers and original packets, acquiring a mapping rule for the Legacy SPE, and re-associating the SFC header with the processed packet using this mapping rule to form a new service routing packet.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the SFC header is stripped off before sending to Legacy SPE, then the Legacy SPE can process the original packet, but the SFC header is lost and cannot be re-associated with the processed packet
Solution Approach 1:
The SFE performs preliminary actions by temporarily storing the correspondence between the SFC header and the original packet before sending the original packet to the Legacy SPE. This preliminary storage enables later re-association of the SFC header with the processed packet, preventing information loss while maintaining compatibility with Legacy SPEs that cannot handle encapsulated packets.
Solution Approach 2:
The SFE acts as an intermediary between the SFC header and the Legacy SPE. It strips the SFC header before forwarding to the Legacy SPE, processes the original packet, and then re-associates the SFC header with the processed packet using the temporarily stored correspondence. This intermediary role enables communication between systems with different capabilities.
2Reliability
If the SFC header is kept with the packet, then the service function chain information is maintained, but the Legacy SPE cannot process the packet
Solution Approach 1:
The packet processing is segmented into distinct phases: the SFC header is separated from the original packet before being sent to the Legacy SPE, and then re-associated after processing. This segmentation allows the Legacy SPE to process only the original packet while the SFE manages the SFC header, enabling both service function chain integrity and Legacy SPE compatibility.
Solution Approach 2:
The SFE performs the preliminary action of stripping the SFC header before forwarding to the Legacy SPE, and then performs the re-association action after processing. This two-stage approach ensures that the Legacy SPE receives only compatible packets while the SFC header information is preserved and re-linked to maintain service function chain integrity.
3Device complexity
If the SFC header is stripped and not re-associated, then processing is simpler, but the service function chain processing is abnormally interrupted
Solution Approach 1:
The SFE creates a copy of the SFC header correspondence and stores it temporarily before processing. This copying mechanism allows the original SFC header to be preserved while enabling simple processing by the Legacy SPE on the original packet. After processing, the copied correspondence is used to re-associate the SFC header, ensuring service function chain continuity without significantly increasing processing complexity.
Data Source
AI summary
Embodiments of the present application disclose a method for encapsulating a service routing packet, including: receiving a first packet, and determining that a next hop is a Legacy SPE; temporarily storing a correspondence between an SFC header and a first original packet that are included in the first packet, and sending the first original packet to the Legacy SPE; receiving a returned second original packet, and determining, according to an acquired mapping rule of an original packet of the Legacy SPE, that the SFC header of the first packet corresponds to the second original packet; and encapsulating the SFC header of the first packet in the second original packet, to form a new service routing packet. By means of the embodiments of the present application, a problem of an abnormal interruption caused by a loss of an SFC header can be avoided.