Inter-domain QoS Reservation via Label Stacking
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Solution Overview
Problem
Current inter-domain traffic engineering techniques lack sufficient reliability and granularity to provide quality of service (QoS) guarantees for time-affected services traversing multiple autonomous systems (AS), particularly failing to support end-to-end QoS reservations and per-flow discrimination.
Innovation Solution
A method for inter-domain QoS reservation and packet forwarding that involves routers sending request messages to set up QoS reservations, receiving acknowledgments, reserving resources, and encapsulating packets with specific labels to indicate inter-domain traffic, enabling proper routing across multiple ASs, and extending Multi-Protocol Label Switching (MPLS) and Resource Reservation Protocol (RSVP) for inter-AS deployment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If common BGP path attributes are used for inter-domain routing, then routing flexibility is improved, but QoS reliability deteriorates because insufficient QoS guarantees are provided for time-affected services
Solution Approach 1:
The patent segments the label stack into multiple functional components: a domain-local label for intra-AS routing and an inter-domain label for cross-AS identification. This segmentation allows independent optimization of routing flexibility (via BGP path attributes) and QoS reliability (via reserved label values and resource reservation protocols) without mutual interference.
Solution Approach 2:
The patent introduces an intermediary label stacking mechanism that mediates between BGP routing decisions and QoS requirements. The label stack acts as an intermediary layer that carries both routing information (for flexibility) and QoS parameters (for reliability), enabling both functions to coexist without direct conflict.
2Device complexity
If existing inter-domain traffic engineering techniques are used, then device complexity is reduced, but QoS granularity deteriorates due to lack of per-flow discrimination capability
Solution Approach 1:
The patent adds a new dimension to packet classification by introducing label stack depth and label value patterns as additional classification dimensions. Instead of relying solely on traditional flow identification methods, the system uses the multi-dimensional label structure (multiple labels with different functions) to achieve fine-grained per-flow QoS discrimination while maintaining relatively simple forwarding logic.
3Reliability
If resources are reserved for inter-domain QoS, then QoS guarantee is improved, but resource allocation flexibility deteriorates due to rigid reservation requirements
Solution Approach 1:
The patent implements dynamic resource allocation within the label switching framework. The label stack structure allows dynamic assignment of domain-local labels that can be reassigned or repurposed based on current network conditions and traffic patterns, while the inter-domain labels maintain stable QoS guarantees. This dynamic behavior enables both QoS reliability and resource allocation flexibility to coexist.
Data Source
AI summary
Methods and router for receiving a request message addressed from a first router to setup an inter-domain QoS reservation toward a second router in a further domain, forwarding the request message to setup the inter-domain QoS reservation, receiving an acknowledgment message to confirm that the inter-domain QoS reservation is setup, reserving resources in accordance with the inter-domain QoS reservation, forwarding the acknowledgment message toward the first router, receiving a packet related to the inter-domain QoS reservation and encapsulating, toward the second router, the packet in accordance with the inter-domain QoS reservation by adding a first label to the packet, the first label indicating that the packet is not for delivery in the current domain. Optionally, the methods and the router could encapsulate the first label and the packet by adding a second label thereto, wherein the second label enables proper routing of the thereby encapsulated packet within the current domain.