IOS XR

IOS XR is a train of Cisco Systems' widely deployed Internetworking Operating System (IOS), used on their high-end Network Converging System(NCS), carrier-grade routers such as the CRS series, 12000 series, and ASR9000 series.

According to Cisco's product literature, IOS XR shares very little infrastructure with the other IOS trains, and is instead built upon a "preemptive, memory protected, multitasking, microkernel-based operating system". The microkernel is provided by QNX.

IOS XR aims to provide the following advantages over the earlier IOS trains:

IOS XR was announced along with the CRS-1 in May 2004. The first generally available version was 2.0. The most recent release is version 6.0 which was released on 23 December 2015.

Other significant releases include the following.

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