KDDI R&D Laboratories, 2-1-15 Ohara, Fujimino, Saitama, 356-8502 Japan. *National Institute of Information and Communications Technology (NICT), 4-2-1, ...
Architecture for Optical Packet Switching Network with Openflow Control Xiaoyuan Cao, Noboru Yoshikane, Takehiro Tsuritani, Itsuro Morita, Takaya Miyazawa* and Naoya Wada* KDDI R&D Laboratories, 2-1-15 Ohara, Fujimino, Saitama, 356-8502 Japan. *National Institute of Information and Communications Technology (NICT), 4-2-1, Nukui-Kitamachi, Koganei, Tokyo 184-8795, Japan {xi-cao, yoshikane, tsuri, morita}@kddilabs.jp, *{takaya, wada}@nict.go.jp
From the carrier’s perspectives, one critical issue is how to accommodate the ever-increasing traffic and diversified services while saving CAPEX and OPEX. Optical network plays an important role in traffic data transmission. However, current circuit switching based optical network has quite low network efficiency and is facing a severe challenge on adapting to the future traffic dynamics. Although optical packet switching (OPS) [1] was proposed as a key technology to address these problems, complex control logic design has been a big obstacle in its way of both research and commercialization. Fortunately, with the introduction of SDN/Openflow [2], this obstacle can be offloaded into a much more flexible and programmable software-based control plane, therefore making OPS network more feasible. Here we propose our architectural design of OPS network with Openflow control (OF-OPS). OF-OPS network architecture: As shown in Fig. 1, an OF-OPS network mainly comprises of a SDN Controller [3] and Openflow-based OPS nodes. Due to the flow-based Openflow control, incoming packets are classified and aggregated into flows at the border node, and assigned with a unique label, which is included in the matching field of the extended Flowtable. Extended Openflow protocol is supported in the OF-OPS node, where Flowtable is embedded as the rule for packet forwarding. Each OF-OPS node will send unmatched packets to the Controller, where available routes and resources are calculated and provided for each flow. For the following packets of this flow, a match against the label will be found in the Flowtable and packets will be switched according to the instructions. Thanks to Openflow, traditional complex control functions (routing, resource allocation, etc.) can be offloaded to the centralized Controller, while OPS node is only in charge of distributed Flowtable matching and packet forwarding. To decrease contention and also enhance network survivability, OF-OPS nodes will dynamically report their link/port status to the SDN controller for path recalculation and Flowtable adjustment. OF-OPS network with Openflow Agents (OFA): Unfortunately, such an OF-OPS node described above is still not available at this moment. However, with the introduction of additional OFA between SDN Controller and the regular OPS nodes, OPS network can still be controlled via Openflow. After the world’s first research conducted by NICT on inter-networking between Openflow networks and an independent OPS network [4, 5], here we demonstrate how to control such an OPS network directly via Openflow. The regular OPS node we used attaches OP_ID (label) to packets according to its label-mapping table and forwards packets according to its own forwarding table. In order to configure its label-mapping table and forwarding table via Openflow, the OFA virtualizes the OPS node and interacts with the Controller. First packet is received and forwarded to the Controller by the edge Openflow switch. Whenever OFA receives a request from the Controller for Flowtable modification, it abstracts the corresponding information (label, ports, etc.) and translates it into standard commands, which are sent to the OPS node for table configurations. The network architecture and experimental results are shown in Fig. 2.
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Fig. 1 OF-OPS network
Fig. 2 OF-OPS network with OFA
This work is partially supported by Ministry of Internal Affairs and Communications (MIC) "STRAUSS", Japan References [1] [2] [3] [4] [5]
Renaud M., et al., IEEE Communications Magazine., Vol.35, No.4, pp. 96-l02, l997. “The OpenFlow switch consortium,” http://www.openflow.org/. “The Opendaylight consortium”, http://www.opendaylight.org/. T. Miyazawa, iPOP 2013, Tokyo, Japan, May 2013. H. Harai, ECOC 2013, Mo.4.E.1, September 2013.
