Foreword

Omar Cherkaoui, Masum Z. Hasan, Guy Pujolle
2009 Annales des télécommunications  
The concept of virtualization is not new to the networking and computing communities. IBM initially pioneered the concept by supporting computing element (CE) virtualization on mainframe computers. A VMM (virtual machine monitor, such as IBM VM-CP) running on and controlling the bare-metal hardware supported multiple VMs with their own guest operating systems (OS) and applications. Similar virtualization technology (also known as OS/server/desktop virtualization) is now being supported on CEs
more » ... sed on the ubiquitous x86 architecture. The virtualization paradigm is also being supported in network elements, (NE, routers, switches) as VLAN (virtual local area network), VPN (virtual private network), VSAN (virtual storage area network), and virtual switch/router, which can be termed as NE or network virtualization. Recently the GENI project has defined network virtualization as: network virtualization is the process of combining hardware and software network resources and network functionality into a single, software-based administrative entity, a virtual network. In network virtualization, the most popular service is the virtual router. A virtual router (VR) has exactly the same functionalities as a physical router, and therefore can inherit all existing mechanisms and tools for configuration, deployment, operation, troubleshooting, monitoring, and accounting. Multiple virtual routers can exist in a single physical device (that way, a VR is conceptually similar to the CE virtualization to certain extent). This special issue features five papers focusing mainly on network virtualization, and also utilization of CE virtualization for the realization of network virtualization. A brief overview of each of the papers is provided below. The first paper "The , introduces two new concepts denoted as Network Planes and Parallel Internets. These concepts represent abstract network capabilities along which connectivity service provisioning can be differentiated. These concepts are packaged into the overall AGAVE Framework. This framework has been designed to ease the enforcement of differentiated connectivity services into an IP Network Provider domain and their delivery to Service Providers. This framework advocates a clear separation between IP Network Provider and Service Provider roles and a clear interface between them. The second paper "Enhancing virtual environments with QoS aware resource management" by Fernando Rodriguez-Haro, Felix Freitag, and Leandro Navarro evaluates different alternatives under Xen software for building an enhanced management system for virtual CPU resources. The authors compare these alternatives in terms of performance, flexibility, and ease of use. This comparison allows proposing a new architecture able to provide a highlevel service which combines inter-domain communication
doi:10.1007/s12243-009-0117-y fatcat:cn4vftlv7bc73c6a4lm4qmgkvm