Wyniki 1-2 spośród 2 dla zapytania: authorDesc:"Jacek Andrzej Litka"

Overview of scalability and reliability problem in sdn networks DOI:10.15199/59.2016.5.3


  In the paper an overview of scalability and reliability in the SDN (Software Defined Networks) networks has been presented. Problems and limitations for guaranteeing scalability and reliability in SDN networks have been indicated. Known methods for assuring scalability and reliability in SDN networks have been described. Projects from research communities for resolving issues with scalability and reliability in SDN networks have been presented. Scientific projects have been categorized based on their common features and the methods for resolving the issues with scalability and reliability. A future field of scientific research has been outlined and all of the presented projects have been graded based on their functionality. Key words: SDN network, scalability, reliability, SDN switch, SDN controller, load balancing, failover, Onix, HyperFlow, DIFANE, DISCO, Kandoo, DevoFlow.In the paper an overview of scalability and reliability in the SDN (Software Defined Networks) networks has been presented. Problems and limitations for guaranteeing scalability and reliability in SDN networks have been indicated. Known methods for assuring scalability and reliability in SDN networks have been described. Projects from research communities for resolving issues with scalability and reliability in SDN networks have been presented. Scientific projects have been categorized based on their common features and the methods for resolving the issues with scalability and reliability. A future field of scientific research has been outlined and all of the presented projects have been graded based on their functionality. Key words: SDN network, scalability, reliability, SDN switch, SDN controller, load balancing, failover, Onix, HyperFlow, DIFANE, DISCO, Kandoo, DevoFlowIn its principal SDN divides control plane and transport plane into separate network entities. SDN-enabled switches and SDN controllers work as a bulk of an SDN network. This division was su[...]

MODEL FOR MEASUREMENT OF FLOW INSTALLATION TIME IN SDN SWITCH DOI:10.15199/59.2017.8-9.70


  SDN is a novel approach that decouples the control plane from data forwarding plane [1]. This is achievable by designating a controller, which sole role is to design rules for traffic forwarding [1]. Controllers install forwarding rules into switches allowing them to forward traffic accordingly. The most popular protocol for SDN is OpenFlow [1, 2]. OpenFlow packets transport information between controller and switch about the state of the network and switches [3]. A packet incoming is checked with the flow table. When there is a match, a switch does a specified action on the packet, including: forwarding to a different output, dropping it or changing its contents. In a scenario, when there is no matching flow, the packet is encapsulated into OpenFlow’s “Packet-in" packet and sent to the controller [2]. The controller checks if there is a rule for such a packet, after which it either drops it (in case there is no matching rule) or installs appropriate flow into the switch (by sending “Flow-mod" message) and forwards the packet accordingly (with the “Packet-out" message) [4]. From this we may indicate that an example where there is a number of switches connected to a single controller may be undesirable in case there is a high number of match misses and a number of packets is send to the controller for checkups [5]. Time that installation of the flow may take might have an impact on an overall performance of the network. The number of flows being installed in the switches might become an impactful hindrance. The time of a flow installation must be relatively short, as the significant factor is controller’s time of response. In case the packets do not find a matching flow, they are treated accordingly to a special “table-miss" rule [6]. Usually it is declared to send packets to the controller [6]. However, this does not mitigate situation in which more than one packet with the same require[...]

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