A network administrator divides a physical system (PS) into multiple virtual systems (VSs) using hardware- and software-level emulation. Each VS performs independent routing tasks. VSs share the same software package and all public resources, including the same IPU, but each interface works only for one VS.
As the demand on various types of network services is growing, network management becomes more complex. Requirements for service isolation, system security, and reliability are steadily increasing. The virtual private network (VPN) technique can be used to isolate services on a PS. If a module failure occurs on the PS, all services configured on the PS will be interrupted. To prevent service interruptions, the VS technique is used to partition a PS into several VSs. Each VS functions as an independent network element and uses separate physical resources to isolate services.
Further development of the distributed routing and switching systems allows the VS technique to fully utilize the service processing capability of a single PS. The VS technique helps simplify network deployment and management, and strengthen system security and reliability.
Service integrity: Each VS has all the functions of a common router to carry services. Each VS has an independent control plane, which allows rapid response to future network services and makes network services more configurable and manageable.
Service isolation: A VS is a virtual router on both the software and hardware planes. A software or hardware fault in a VS does not affect other VSs. The VS technique ensures network security and stability.
Expenditure reduction: As an important feature of new-generation IP bearer devices, VSs play an active role in centralized operation of service provider (SP) services, reducing capital expenditure (CAPEX) or operational expenditure (OPEX).