In-band control, queuing, and failure recovery functionalities for openflow

In OpenFlow, a network as a whole can be controlled from one or more external entities (controllers) using in-band or out-of-band control networks. In this article, we propose in-band control, queuing, and failure recovery functionalities for OpenFlow. In addition, we report experimental studies and practical challenges for implementing these functionalities in existing software packages containing different versions of OpenFlow. The experimental results show that the in-band control functionality is suitable for all types of topologies. The results with the queuing functionality show that control traffic can be served with the highest priority in in-band networks and hence, data traffic cannot affect the communication between the controller and networking devices. The results with the failure recovery functionality show that traffic can be recovered from failures within 50 ms

Software defined networking: meeting carrier grade requirements

Software Defined Networking is a networking paradigm which allows network operators to manage networking elements using software running on an external server. This is accomplished by a split in the architecture between the forwarding element and the control element. Two technologies which allow this split for packet networks are ForCES and Openflow. We present energy efficiency and resilience aspects of carrier grade networks which can be met by Openflow. We implement flow restoration and run extensive experiments in an emulated carrier grade network. We show that Openflow can restore traffic quite fast, but its dependency on a centralized controller means that it will be hard to achieve 50 ms restoration in large networks serving many flows. In order to achieve 50 ms recovery, protection will be required in carrier grade networks

Performance Evaluation of MPLS in a Virtualized Service Provider Core (with/without Class of Service)

The last decade has witnessed a major change in the types of traffic scaling the Internet. With the development of real-time applications several challenges were faced within traditional IP networks. Some of these challenges are delay, increased costs faced by the service provider and customer, limited scalability, separate infrastructure costs and high administrative overheads to manage large networks etc. To combat these challenges, researchers have steered towards finding alternate solutions. Over the recent years, we have seen an introduction of a number of virtualized platforms and solutions being offered in the networking industry. Virtual load balancers, virtual firewalls, virtual routers, virtual intrusion detection and preventions systems are just a few examples within the Network Function Virtualization world! Service Providers are trying to find solutions where they could reduce operational expenses while at the same time meet the growing bandwidth demands of their customers. The main aim of this thesis is to evaluate the performance of voice, data and video traffic in a virtualized service provider core. Observations are made on how these traffic types perform on congested vs uncongested links and how Quality of Service treats traffic in a virtualized Service Provider Core using Round Trip Time as a performance metric. This thesis also tries to find if resiliency features such as Fast Reroute provide an additional advantage in failover scenarios within virtualized service provider cores. Juniper Networks vSRX are used to replicate virtual routers in a virtualized service provider core. Twenty-Four tests are carried out to gain a better understanding of how real-time applications and resiliency methods perform in virtualized networks. It is observed that a trade-off exists when introducing QoS on congested primary and secondary label switched paths. What can be observed thru the graphs is having Quality of Service enabled drops more packets however gives us the advantage of lower Round Trip Time for in-profile traffic. On the hand, having Quality of Service disabled, permits more traffic but leads to bandwidth contention between the three traffic classes leading to higher Round-Trip Times. The true benefit of QoS is seen in traffic congestion scenarios. The test bed built in this thesis, shows us that Fast Reroute does not add a significant benefit to aid in the reduction of packet loss during failover scenarios between primary and secondary paths. However, in certain scenarios fast reroute does seem to reduce packet loss specifically for data traffic