Xiaoyuan Cao

Dynamic Openflow-Controlled Optical Packet Switching Network

This paper presents and experimentally demonstrates the generalized architecture of Openflow-controlled optical packet switching (OPS) network. Openflow control is enabled by introducing the Openflow/OPS agent into the OPS network, which realizes the Openflow protocol translation and message exchange between the Openflow control plane and the underlying OPS nodes. With software-defined networking (SDN) and Openflow technique, the complex control functions of the conventional OPS network can be offloaded into a centralized and flexible control plane, while promoted control and operations can be provided due to centralized coordination of network resources. Furthermore, a contention-aware routing/rerouting strategy as well as a fast network adjustment mechanism is proposed and demonstrated for the first time as advanced Openflow control to route traffic and handle the network dynamics. With centralized SDN/Openflow control, the OPS network has the potential to have better resource utilization and enhanced network resilience at lower cost and less node complexity. Our work will accelerate the development of both OPS and SDN evolution.

Dynamic multi-domain virtual optical network deployment with heterogeneous control domains [invited]

We propose a multi-domain resource broker to dynamically provision multi-domain virtual optical networks across heterogeneous control domains (i.e., GMPLS and OpenFlow) and transport (i.e., optical packet switching and elastic optical networks) technologies. We have designed, implemented, and experimentally evaluated the multi-domain resource broker in an international testbed across Spain, the UK, and Japan.

Openflow-controlled optical packet switching network with advanced handling of network dynamics

We have experimentally demonstrated Openflow-controlled optical packet switching network, while also proposed and demonstrated an advanced Openflow control mechanism to handle the network dynamics with prompt response.

First demonstration of holistically-organized metro-embedded cloud platform with all-optical interconnections for virtual datacenter provisioning

We demonstrated a novel metro-embedded datacenter architecture with intra-datacenter optical burst switching ring and inter-datacenter optical burst switching over wavelength switched optical network interconnections, and virtual datacenter provisioning under the coordination of SDN control plane.

Dynamic Multi-domain Virtual Optical Networks Deployment with Heterogeneous Control Domains

We propose a resource broker to dynamically provision multi-domain VON across heterogeneous control (GMPLS, OpenFlow) domains and transport (OPS, EON) technologies. Experimental evaluation has been performed in an international testbed across Spain, UK and Japan.

Software-defined optical networks and network abstraction with functional service design [Invited]

The combination of software-defined networking (SDN) and optics, i.e., a software-defined optical network (SDON), offers combined benefits that include flexible SDN control and large optical transport capacity. In this paper, we introduce the unified SDN as a common control solution for end-to-end OCS/OPS networks, with the introduction of an additional network element, namely the OpenFlow agent. The SDN control plane is implemented in the OPS network for simplified data plane design, optimal network organization, and contention alleviation, as well as improved control flexibility and advanced handling of network dynamics. The SDON demonstration is conducted in the nationwide transport networks constructed with different technologies via various internetworking testbeds. Based on the SDON platform, we further introduce the service design concept for advanced network abstraction. The general network architecture based on a service design concept offering flexible, reconfigurable, and economical end-to-end (FREE) service features is described. This service design aims to provide customized service and maximum network freedom with virtualized and flexibly selected functionalities, while maintaining a moderate network configuration cost and promoting network innovation at the same time. Moreover, the service design concept could easily be extended to any layers and any network domains, thus providing the unified network abstraction ability and the end-to-end control solution. Based on the service design, control, coordinated, and orchestrated optical transmission is demonstrated by reconfiguring the virtualized optical functions. This type of approach to network abstraction is further exploited in the heterogeneous multidomain networks, where differentiated and featured service provisioning is demonstrated.

Optimal and dynamic virtual datacenter provisioning over metro-embedded datacenters with holistic SDN orchestration

Abstract Conventional mega datacenter (DC) lacks flexibility and has poor service connectivity for users faraway. Therefore, the metro-embeded DC architecture has been introduced to deliver more reliable and flexible services with less access latency. For fine-grained all-optical switching ability and high bandwidth connection, optical burst switching (OBS) ring is deployed inside the micro-DCs (mDC) and OBS over wavelength switched optical network paradigm is used for inter-mDC communication. Meanwhile, hierarchical SDN control is employed to virtualize and holistically coordinate the distributed mDCs and the metro network slices into reconfigurable virtual DC (VDC). Optimal VDC provisioning based on an integer linear programming (ILP) formulation is also developed in the SDN control plane to provide services with minimum latency and traffic load. A dynamic VDC provisioning algorithm based on partial ILP is further proposed to reconfigure the VDC with reduced complexity considering the user and resource dynamics. Experimental demonstrations conducted on the implemented metro-embedded DC prototype testbed show that optimal and fast VDC provisioning is realized based on the proposed ILP, while dynamic VDC reconfiguration makes sure that VDC is adjusted accordingly with the change of user location and resource requirement.

Dynamic support and demonstration for orchestrated multi-domain software-defined optical networks

Software-defined optical network has the combined benefit of both control flexibility and large transport capacity, thus having the potential of realizing a new ground-breaking optical network framework. In this paper, we introduce our recent efforts that have been devoted to the research supported by the STRAUSS project on SDN/Openflow controlled optical networks. The unified SDN control plane is able to configure the optical nodes/devices and thus the optical network through the cooperation of Openflow agents with more flexibility and optimization, thanks to its global knowledge of network resource and centralized controllability. Furthermore, we are able to interconnect our network with other heterogeneous multi-domain networks, while demonstrating the end-to-end flexible service provisioning over both nationwide and international testbeds with SDN orchestration via unified interface based on control orchestration protocol.

Scalable software-defined optical networking with high-performance routing and wavelength assignment algorithms

The feasibility of software-defined optical networking (SDON) for a practical application critically depends on scalability of centralized control performance. The paper, highly scalable routing and wavelength assignment (RWA) algorithms are investigated on an OpenFlow-based SDON testbed for proof-of-concept demonstration. Efficient RWA algorithms are proposed to achieve high performance in achieving network capacity with reduced computation cost, which is a significant attribute in a scalable centralized-control SDON. The proposed heuristic RWA algorithms differ in the orders of request processes and in the procedures of routing table updates. Combined in a shortest-path-based routing algorithm, a hottest-request-first processing policy that considers demand intensity and end-to-end distance information offers both the highest throughput of networks and acceptable computation scalability. We further investigate trade-off relationship between network throughput and computation complexity in routing table update procedure by a simulation study.

Adaptive DC interconnection provisioning in distributed all-optical micro-datacenters using holistically SDN orchestration for dynamic access

The metro-embedded datacenter (ME-DC) architecture which is based on micro-DCs (mDC) is introduced and implemented to deliver more flexible services with less access latency. Hierarchical SDN control is employed to adaptively interconnect the distributed mDCs and the metro network slices into re-configurable virtual DC (VDC). Such an approach improves the overall resource mobility, especially for traveling users that need to dynamically access the service. In this paper, the VDC re-configuration and pre-configuration mechanisms for dynamic user access are proposed and demonstrated for the first time. In specific, by re-configuring the VDC with the most accessible resources with user location tracking, fast and flexible service is provided with consistent service access. Furthermore, by pre-configuring the VDC with user prediction, mDC and metro network resources are reserved in advance for users in order to provide seamless service. Demonstration based on the implemented ME-DC prototype shows that VDC is adaptively constructed for dynamic user access with fast and flexible service provisioning.