Vology

A Protected System Domain (PSD) is a redundant Routing Engine pair (or single Routing Engine) on the JCS1200 platform matched with one or more Flexible PIC Concentrators (FPCs) on a T Series router.The concept of virtual hardware routers, or Protected System Domains (PSDs), is an extension of the existing JUNOS software feature of logical systems. A logical system partitions a single, physical router into multiple logical devices that perform independent routing tasks. Logical systems reduce complexity by performing a subset of the actions of the main router and by having their own unique routing tables, interfaces, policies, and routing instances. A set of logical systems within a single router can handle the functions previously performed by several small routers.In contrast, a PSD has its own control plane as well as forwarding plane. A PSD functions exactly as a separate physical router, running a separate configuration file, administering its own domain, and requiring unique authentication in order to access it. By providing a highly scalable control plane with a cost-efficient forwarding plane on a single platform, the JCS 1200 chassis interconnected with up to three T-series routing chassis obviates the need to deploy numerous physical routers.