The Most Common Software-Defined Networks - Essay Example

?Software defined networks (SDN) The most common software defined networks (SDN) definition revolves around splitting the data plane or the Ethernet switch forwarding hardware from its control plane or the logic involved in the packet flowing to egress from ingress. The SDN definition based upon Open Flow offers a standard based Application Programming Interface (API) that links a controller and an Ethernet switch. From an architectures point of view, what is along side or on top of the controller is another set of APIs or API that virtualizes networking like what VMware does for serves (Greene, K, 2009.). According to capability and application definition SDN seeks to provide a standard based application development platform and commoditize network hardware. This includes taking most of the functionality and features that exist in custom proprietary software then directing it in to an open SDN space. An in-depth on how SDN is implemented is that the system is incorporated in underutilized servers that information technology organizations already operate and own. In summary, the firmware of routers and network switches that has for a long time remained under the control of the companies that manufacture this equipment is been changed by making this remotely modifiable and remotely accessible through third party software clients, making use of open flow an example an open protocol. SDN allows for external access to the innards of routers and switches that were formally proprietary and closed and also for quick optimization and experimenting of routing or switching policies. The switching fabric of conventional Layer 2/3 networks serves as a routing and switching fabric for the blade center server chassis. These switches have the capability of layer 2 switching and layer three routing providing security and flexible traffic management in the chassis. The layer 2/3 fiber GbE and Copper switching modules provides full layer 2 switching making capabilities available such as link aggregation control, Cisco Ether channel, advanced spanning tree protocols and 802.1Q VLANs, Internet Group Management Protocol (IGMP), performance features and application delivery such as granular QOS, multicasting and snooping (‘Nortel Networks Layer 2/3 Gbe Switch Module’ 2004). The open flow technology showcases network programmability through the remote control application. This is all about remotely and directly programming a network switch to handle traffic dynamically in a particular way making use of the CLI type of commands. An example, to achieve the forward flow to a particular switch port, ensure other flows are blocked, while the switch is programmed to make such actions alternate in a predefined manner i.e. time interval of say 40 seconds. Use this demonstration using a number of servers that are to listen to the same multicast address while the switch is being programmed to allow a single server to give air play to a single client in the case of video servers. This application is applicable in the context of software defined networking as it empowers the operator, user and administrator to have an own definition of treating traffic. This, in a way, resembles the activities and operations of a TV remote control where one is able to switch through channels only that in this case it is automatic. This is transparent to the end host in that clients and video servers are unaware of the switch managing or controlling the traffic (Anderson, c, et al, 2009 Remote Control SDN). A command line interface (CLI) is a dialog or an interface where two programs or the user and the program pass a command line in SDN it is an essential key aspect. Such command lines used in software defined networks are some of the windows shell and OS/2 presentation manager these graphical interfaces helps programs and users communicate with their execution strategies such as opening programs and documents. The registry or the graphical shell is where these commands are stored. In SDN standard input/output interface (stdin $ stdout) can be employed to look for console hacks allowed in order to store and edit commands in software (Pike, R and Kerninghan, B, 1984). In a disaster recovery scenario where it is found necessary for the migration of machines from the live data centers to a hot/warm standby, the evaluation deployment of an application stack known as LAMP (Linux, Apache, MySQL, and PHP) that uses Xen open source software can be incorporated. The hypervisor or virtual machine monitor is software that allows for multiplexing and migration of virtual machines from one physical system to another (Clark, C et al, 2005). This software creates a virtual hardware platform regardless of the physical system. Live migration can be achieved without interfering with the execution of the guest OS on the virtual machine. Live migration has benefits such as system management events, dynamic relocation of OS in response to performance needs. In this example of live data migration environment, the Linux and Xen hypervisor software are the key components used. The hypervisor is an open source software package that manages and creates partitions for multiple virtual machines. In this virtualization, the guest OS are aware of the fact that they are running in a virtualized environment (Barham, P, et al, 2003, p 164-177). Xen uses a virtualization architecture known as para-virtualization, with para-virtualization the guest OS is enabled to make hyper calls to the hypervisor privileged operations, instead of the regular system calls in unmodified OS. Another of migration of migration of virtual machines from the live data centers to a hot/warm standby is Virtual box, which is, a type 2 hypervisor that runs with a conventional operating system environment. With the second software level acting as the hypervisor layer, the guest operating system runs at the third level which is above the hardware. Virtual box is an x86 virtualization package that is developed by Oracle Corporation as part of its virtualization products. The software is installed on an existing host operating system acting as an application; the host application allows gust operating systems, known as guest OS, to be run and loaded, if many each with an own virtual environment. Oracle VM virtual box supports hosts operating systems such as Mac OS X, Solaris, and Windows vista, Linux, Windows XP, Windows 7 and Open Solaris. It also supports a number of guest operating systems which include derivations and versions of Linux, Windows, OS/2, BSD and Solaris. In the absence of hardware based assisted, virtualization, a software based virtualization approach is adopted by Virtual Box. A 32 bit guest OS, which run in ring 3 and 0 of the Intel ring architecture, is supported by this mode. In hardware, assisted virtualization virtual box supports both AMD’s AMD-V and Intel’s VT-x hardware virtualizations. Virtual Box can run each guest virtual machine in its own separate address space; some of the guests including SMP guests and certain proprietary, 64 bit guests are only supported by Virtual Box if their hosts have hardware assisted virtualization ((Travostino, F, et al, 2006, p 901-907). References Anderson, C, et al, 2009, Remote Control SDN, Practical symposium forum. Barham, P, et al, 2003, p 164-177, Xen and the Art of Virtualization. In Proc, SOSP. Clark, C. et al, 2005, Live Migration of Virtual Machines, 2nd Symposium on Networked Systems Design and Implementation (NSDI). Greene, K, 2009, Software Defined Networking, technology review. Nortel Networks Layer 2/3 Gbe Switch Module for IBM, 2004, server Blade Center, Installation Guide, First Ed. Travostino, F, et al, 2006, p 901-907, Seamless Live Migration of Virtual Machines over the MAN/LAN. Future Gener, Comput, Syst. Pike, R and Kerninghan, B, 1984, the UNIX Programming Environment: Command Lines, Acorn Computers. Read More