Inter-domain SDN Traffic Engineering Resource Allocation
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Solution Overview
Problem
In large software-defined networks (SDN), centralized controllers face challenges in efficiently managing resource provisioning due to increased computational complexity and latency, especially when predicting resource requirements for inter-domain traffic, leading to inefficient resource allocation and reduced performance.
Innovation Solution
The implementation of inter-domain SDN traffic engineering techniques that involve receiving border element information from multiple SDN controllers, computing inter-domain allocation constraints, and provisioning resources to reserve capacity for inter-domain traffic, ensuring equitable access to resources and maintaining minimum throughput rates, either through centralized or distributed methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If centralized SDN controllers are used to manage resource provisioning in large networks, then network service management is achieved through abstraction of lower level functionality, but latencies involved with collecting network information and distributing provisioning instructions significantly delay policy implementation
Solution Approach 1:
The network is divided into multiple domains, each managed by a local SDN controller that handles resource provisioning independently. This segmentation allows parallel processing of provisioning requests across domains, eliminating the single-point bottleneck of centralized controllers and significantly reducing policy implementation latency while maintaining standardized interfaces for network-wide coordination.
Solution Approach 2:
The architecture transitions from a single-dimensional centralized control model to a multi-dimensional hierarchical control structure, where control functions are distributed across multiple layers (local domain controllers, inter-domain controllers, and centralized coordination). This dimensional expansion enables simultaneous local optimization and global coordination, reducing implementation delays through parallel decision-making at different hierarchical levels.
2Reliability
If centralized SDN controllers service large networks, then comprehensive network control is achieved, but computational complexity of optimization algorithms increases significantly as additional links are added
Solution Approach 1:
The computational workload of optimization algorithms is segmented and distributed to local SDN controllers within each domain. Each controller solves optimization problems only for its local domain, dramatically reducing individual computational complexity compared to a centralized solver handling the entire network. Inter-domain optimization is handled separately by inter-domain controllers, creating a divide-and-conquer approach that maintains comprehensive control while managing complexity.
Solution Approach 2:
Each local SDN controller performs optimization for its specific domain rather than attempting to optimize the entire network globally. This partial action approach allows controllers to use simpler, faster optimization algorithms tailored to local conditions, while inter-domain coordination ensures overall network optimality is achieved through iterative exchange of border element information and constraints.
3Adaptability or versatility
If resources are reserved for inter-domain traffic, then equitable access to resources is achieved, but available capacity for intra-domain traffic may be reduced
Solution Approach 1:
The system dynamically adjusts resource allocation parameters based on traffic patterns and service level agreements. Border element information and allocation constraints are exchanged between controllers to compute optimal resource reservations that satisfy inter-domain traffic requirements while maximizing intra-domain throughput. This parameter optimization ensures fair access for inter-domain traffic without unnecessarily reducing intra-domain capacity.
Solution Approach 2:
Resource reservations for inter-domain traffic are made dynamic rather than static, allowing the system to adapt to changing network conditions. The inter-domain TE controller continuously monitors border element utilization and adjusts allocation constraints in real-time, releasing reserved capacity when inter-domain traffic demand is low and tightening reservations when demand increases, thereby maintaining both fairness and productivity across varying loads.
Data Source
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AI summary
Constraining resource provisioning by domain controllers based on resource requirements projected for remotely-originating inter-domain traffic can improve utilization efficiency and link reliability in multi-domain software defined network (SDN) architectures. A domain controller may be required to reserve a portion of inter-domain link capacity for transporting remotely-originating traffic. This may limit the inter-domain link capacity available for transporting locally-originating traffic in a manner that ensures remotely-originating traffic flows have equitable and/or adequate access to resources of inter-domain links. Alternatively, a domain controller may be required to maintain a minimum throughput rate for remotely-originating traffic, which may cause remotely-originating traffic to be prioritized over locally-originating traffic when necessary to maintain the minimum throughput rate. Provisioning constraints can be generated in a centralized or distributed fashion.