Copyright © 2012, QoS-aware Network Operating System for Software Defined Networking with Generalized OpenFlows Kwangtae Jeong, Jinwook Kim and Young-Tak Kim 2012 IEEE/IFIP 4th Workshop on Management of the Future Internet 1
Copyright © 2012, Outline Introduction and related work Architecture The QoS-aware Network Operating System(QNOX) Implementation and performance analysis Conclusion 2
Copyright © 2012, Introduction and Related Work The SDN allows network operators to manage network elements using software running on an external server. It splits the network into forwarding and control elements, giving the operators more flexibility to configure their network. The OpenFlow framework provides standardized open protocol in switches and routers. 3
Copyright © 2012, Introduction and Related Work The network operating system (NOX) provides a programming interface with high-level abstractions of network resources. However, it fails in providing the necessary functions for QoS-guaranteed SDN service. In this paper, they proposed a QoS-aware network operating system (QNOX), providing QoS-aware virtual network embedding, end-to-end network QoS assessment, and collaborations among control elements in other domain network. 4
Copyright © 2012, Architecture SE: Service Element, providing a user interface and receiving the service request from users. CE: Control Element, end-to-end session control, routing path establishment, flow table update. ME: Management Element, resource discovery, virtual overlay network, performance monitoring. CKE: Cognitive Knowledge Element, mapping from virtual network topology to substrate network topology. FE: Forwarding Element, e.g., a switch. 5
Copyright © 2012, Architecture 6
Copyright © 2012, QNOX – Resource Discovery When activating a new FE, an UPnP-based protocol is used to automatically connect to ME. ME then informs CE, and then CE calculates a new FIB (forwarding information base) and updates and installs on every FE in this domain. Traditional shortest path spanning tree algorithm. 7
Copyright © 2012, QNOX – Resource Discovery 8
Copyright © 2012, QNOX – Manipulating Service Requests The SE receives service requests with attributes of the required QoS parameters(power of virtual node, delay, jitter, packet error rate, packet loss rate…). SE checks and evaluates the availability of network resources. If the requested QoS level is not available, there may be some negotiation among SE and user. SE also contains the service life-cycle management for the accepted services, and QoE/QoS monitoring modules. 9
Copyright © 2012, QNOX – Inter-Domain Routing PCE, a Path Computation Element, RFC Backward recursive PCE-based path computation. 10
Copyright © 2012, Implementation and Performance Analysis 11 Using modified Linux IP/MPLS router to emulate FE and CE. Each element is individually running on a VMware virtual machine. Each 19 FEs are grouped and installed on a PC server. One of the 19 FEs in the group is providing a direct link to the CE. One CE is configured for a domain network which contains 2~114 FEs.
Copyright © 2012, Implementation and Performance Analysis 12
Copyright © 2012, Implementation and Performance Analysis 13
Copyright © 2012, Conclusion A clear architecture that can run on OpenFlow and legacy network devices simultaneously. Need a mechanism that deals with the QoS problem in runtime. Miss some details and issues in this paper. The evaluation is not convincible. 14