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Software-Defined Network (SDN) is a promising network paradigm that separates the control plane and data plane in the network. It has shown great advantages in simplifying network management such that new functions can be easily supported without physical access to the network switches. However, Ternary Content Addressable Memory (TCAM), as a critical hardware storing rules for high-speed packet processing in SDN-enabled devices, can be supplied to each device with very limited quantity because it is expensive and energy-consuming. To efficiently use TCAM resources, we propose a rule multiplexing scheme, in which the same set of rules deployed on each node apply to the whole flow of a session going through but towards different paths. Based on this scheme, we study the rule placement problem with the objective of minimizing rule space occupation for multiple unicast sessions under QoS constraints. We formulate the optimization problem jointly considering routing engineering and rule placement under both existing and our rule multiplexing schemes. Via an extensive review of the state-of-the-art work, to the best of our knowledge, we are the first to study the non-routing-rule placement problem. Finally, extensive simulations are conducted to show that our proposals significantly outperform existing solutions.
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... The controller converts the policies for traffic management in the form of flow rules and builds them on network devices [13,26]. Every device on the network keeps its flow rule in its Ternary Content Addressable Memory (TCAM) [6]. However, TCAM is considered expensive due to its definite size and has a high power consumption. ...
... In this section, we discussed the related work of various researchers where they have proposed different schemes to improve QoS in the SDN network. We classify the work from various points-QoS aware routing [9,10,23,38], policy management framework [2,3,24,30,32,33,39] and resource allocation [1,6,22,37]. In the QoS-aware routing, network congestion is detected and various measures are taken to reduce congestion. ...
... The proposed scheme uses the flow matrix for rescheduling the traffic flows in the SDN paradigm which resulted in reducing the congestion in the network. The authors in Huang et al. [6], introduced a rule multiplexing method that efficiently utilizes TCAM resources. However, the authors proposed approach only minimizes the rule placement in switches. ...
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... However, the relaxation of the routing policy causes the drawback of longer paths. The researches presented in Huang et al. (2015) and Kosugiyama et al. (2017) propose heuristic algorithms to reduce the total number of flows while respecting the end-to-end QoS. Ashraf (2016) and Galan-Jimenez, Polverini & Cianfrani (2018) focus on minimizing the number of update messages through smart rule aggregation. ...
... Some of the approaches are not capable of handling wildcard or non-prefix addresses (Braun & Menth, 2014b;Rifai et al., 2017;Assefa & Özkasap, 2019). Finally, most of the proposed routing methods do not consider rule conflict issues in aggregation (Huang et al., 2015;Kosugiyama et al., 2017;Bera, Misra & Jamalipour, 2019;Zhao et al., 2020). ...
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Software-defined networking (SDN) enables fast service innovations through network programmability. In SDN, a logically centralized controller compiles a set of policies into the network-level rules. These rules are inserted in the TCAM memory of SDN-enabled switches enabling high-speed matching and forwarding of packets. Unfortunately, TCAMs are available in limited capacities and fall short of accommodating all intended rules, especially in networks with large distinct flows like datacenters. Rule compression is a technique that reduces the number of rules by aggregating them with some similarity factors. This paper introduces WildMinnie, a new rule compression method that aggregates rules based on their common address non-prefix wildcards derived from a group of rules with the same output port number. We explore rule conflict issues and provide solutions to resolve them. We demonstrate the capability of WildMinnie in various datacenter topologies with traffics having different diversity of source-destination addresses and show that WildMinnie outperforms the best-known compression method by 20%, on average.
... Therefore, the load of flow tables in different nodes is balanced. Huang et al. [13] proposed a rule multiplexing scheme. The sub-rules are placed along the path in an arbitrary order, and only one duplicate of the same rule is reserved in the common nodes of different paths. ...
... The sub-rules are placed along the path in an arbitrary order, and only one duplicate of the same rule is reserved in the common nodes of different paths. Based on rule multiplexing, Huang et al. [13] formulates a joint optimization problem of rule placement and TE to minimize rule space occupation. In some cases, the rules or sub-rules may be coupled with the nodes with specific functions, which adds constraint conditions to the problem. ...
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... In [34], [35] recommended an SD-DCN related data centre EO with united contemplation of VM Placement (VMP) together with forwarding rule placement. SDN's inherent TCAM ability limitation feature was regarded particularly. ...
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... The authors in [18] suggested a method based on multiplexing, in which some of the rules can be customized for every node and hence the placement process is done for various paths in an optimized manner. By using the set of rules, occupational space is reduced providing better QoS in both unicast and multicast functions. ...
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