Interchassis Redundancy and Virtual Chassis Overview
As more high-priority voice and video traffic is carried on the network, interchassis redundancy has become a baseline requirement for providing stateful redundancy on broadband subscriber management equipment such as broadband services routers, broadband network gateways, and broadband remote access servers. To provide a stateful interchassis redundancy solution for MX Series 3D Universal Edge Routers, you can configure a Virtual Chassis.
This topic provides an overview of interchassis redundancy and the Virtual Chassis, and explains the benefits of configuring a Virtual Chassis on supported MX Series routers.
Interchassis Redundancy Overview
Traditionally, redundancy in broadband edge equipment has used an intrachassis approach, which focuses on providing redundancy within a single system. However, a single-system redundancy mechanism no longer provides the degree of high availability required by service providers who must carry mission-critical voice and video traffic on their network. Consequently, service providers are requiring interchassis redundancy solutions that can span multiple systems that are colocated or geographically dispersed.
Interchassis redundancy is a high availability feature that prevents network outages and protects routers against access link failures, uplink failures, and wholesale chassis failures without visibly disrupting the attached subscribers or increasing the network management burden for service providers. Network outages can cause service providers to lose revenues and require them to register formal reports with government agencies. A robust interchassis redundancy implementation enables service providers to fulfill strict service-level agreements (SLAs) and avoid unplanned network outages to better meet the needs of their customers.
Virtual Chassis Overview
One approach to providing interchassis redundancy is the Virtual Chassis model. In general terms, a Virtual Chassis configuration enables a collection of member routers to function as a single virtual router, and extends the features available on a single router to the member routers in the Virtual Chassis. The interconnected member routers in a Virtual Chassis are managed as a single network element that appears to the network administrator as a single chassis with additional line card slots, and to the access network as a single system.
To provide a stateful interchassis redundancy solution for MX Series routers, you can configure a Virtual Chassis. An MX Series Virtual Chassis interconnects two MX Series routers into a logical system that you can manage as a single network element. The member routers in a Virtual Chassis are designated as the Virtual Chassis primary router (also known as the protocol primary) and the Virtual Chassis backup router (also known as the protocol backup). The member routers are interconnected by means of dedicated Virtual Chassis ports that you configure on Modular Port Concentrator/Modular Interface Card (MPC/MIC) interfaces.
An MX Series Virtual Chassis is managed by the Virtual Chassis Control Protocol (VCCP), which is a dedicated control protocol based on IS-IS. VCCP runs on the Virtual Chassis port interfaces and is responsible for building the Virtual Chassis topology, electing the Virtual Chassis primary router, and establishing the interchassis routing table to route traffic within the Virtual Chassis.Staring in Junos OS release 20.2R1 you can run the Next Gen Services MX-SPC3 security services card with MX Series Virtual Chassis.
Supported Platforms for MX Series Virtual Chassis
You can configure a Virtual Chassis on the following MX Series routers with MPC/MIC interfaces (for configuration of Virtual Chassis ports) and dual Routing Engines:
MX240 3D Universal Edge Router
MX480 3D Universal Edge Router
MX960 3D Universal Edge Router
Benefits of Configuring a Virtual Chassis
Configuring a Virtual Chassis for MX Series routers provides the following benefits:
Simplifies network management of two routers that are either colocated or geographically dispersed across a Layer 2 point-to-point network.
Provides resiliency against network outages and protects member routers against access link failures, uplink failures, and chassis failures without visibly disrupting attached subscribers or increasing the network management burden for service providers.
Extends the high availability capabilities of applications such as GRES and NSR beyond a single MX Series router to both member routers in the Virtual Chassis.
Enables service providers to fulfill strict service level agreements (SLAs) and avoid unplanned network outages to better meet their customers’ needs.
Provides the ability to scale bandwidth and service capacity as more high-priority voice and video traffic is carried on the network.