Carrier Routing System

Cisco CRS-1 Backbone Core Router

Carrier Routing System is a large-scale core router, developed by Cisco Systems, Inc. It runs IOS XR which is a train of IOS built upon the QNX microkernel. A single chassis holds a maximum of 16 line cards, and can run an OC-768 SONET interface. The system has the capability for combining multiple line card chassis using separate dedicated fabric chassis, allowing one system to replace a cluster of Internet core routers in a single site. In this multi-chassis configuration, each line card chassis (LCC) is connected over multiple fabric switching planes with one or more fabric card chassis (FCC). The chassis interconnections are achieved with PAROLI (parallel optical link) fiber optic bundles.

A fully populated CRS contains over 1000 linecards at 40 Gbit/s each and theoretically can scale to 92 Tbit/s bandwidth via multi-chassis configuration, although multichassis systems of such size were never delivered or shown to public. As of 2009, the largest production CRS-1 system is limited to eight line card chassis, for a total of 10 Tbit/s.

In both single- and multi-chassis configurations, the CRS-1 switch fabrics are based on a three-stage Beneš architecture. In a single-chassis system, the three switching stages—S1, S2, and S3—are all contained on one fabric card. In a multi-chassis system, the S2 stage is contained within the FCCs, with the S1 and S3 stages resident in the LCCs at the egress and ingress interfaces fabric plane interfaces, respectively.

While the device was in development, it was known by the code name of HFR, or Huge Fucking Router. The marketing group later maintained this actually meant Huge Fast Router. This code name was coined in the tradition of Cisco's previous service provider router, the GSR (12000-series), whose development code name was BFR, or Big Fucking Router. BFR even had a logo of a fist punching through a globe. On one of the fingers is a ring with the industry-standard blue router icon, and below the logo it says "BFR" on a banner. This same logo can be seen on the internals of some early GSR line cards. All CRS-1 software package file names start with "hfr-" (e.g., "hfr-fpd.pie-3.4.2" is the FPGA image).

At launch time in 2004, Cisco CRS-1 became the largest production router in existence, although it featured the same 40 Gbit/s/slot density as the first-generation T-series router (T640) launched by Cisco's archrival Juniper Networks two years earlier (2002). Effectively, CRS-1 16 delivered twice the capacity of competition in twice the space (non-standard full rack). Cisco's new Carrier Routing System included support for hardware-based virtual routers (SDRs) and remote process placement in IOS-XR. Other innovative features announced at launch (i.e. ISSU and self-healing) became significantly delayed. Multichassis version of CRS-1 16 as well as smaller chassis types (CRS-1 8 and CRS-1 4) became commercially available post-FRS.

Model comparison

As of August 2010 the CRS has two families (CRS-1 and CRS-3) with each 4 models of main-chassis.

Model	# interface-slots	maxswitching-capacity per system	Dimensions in cm. L x B x H (excl. front-cover and cable-mgt)	max power consumption max. capacity power-converters	max. nr. of 10 Gb ethernet interfaces	Link to product-specs plus: Overview of the CRS-1 series
CRS-1 4 slot single shelf	4	320 Gbit/s	76.9 x 44.8 x 76.91	2551 Watt 4 kW	32	Introducing the 4 slots CRS-1 Interactive presentation CRS-1:4
CRS-1 8 slot single shelf	8	640 Gbit/s	99.06 x 44.45 x 93.0	4834 Watt 7 kW	64	Introducing the 8 slots CRS-1 Cisco CRS-1 8-Slot Single-Shelf System
CRS-1 16 slot single shelf	16	1.2 Tbit/s	213.36 x 59.94 x 91.44	9630 Watt 13.2 kW	128	Presentation of 16 slots CRS-1 Cisco CRS-1 16-Slot Single-Shelf System
CRS-1 multishelf platform	1152	92 Tbit/s	213.36 x 59.94 x 91.44 dimensions are per shelf maximum 70 shelves in one system		8,216	General brochure for the CRS-1 series Cisco CRS-1 24-Slot Fabric-Card Chassis
CRS-3 4 slot single shelf	4	1.12 Tbit/s	76.2 x 47.12 x 76.91	? 4 kW	4 slots per shelf x 10	CRS-3 Video datasheet
CRS-3 8 slot single shelf	8	2.24 Tbit/s	99.06 x 44.45 x 93.0	? 7 kW	8 slots per shelf x 10
CRS-3 16 slot single shelf	16	4.48 Tbit/s	213.36 x 59.94 x 91.44	? 13.2 kW	16 slots per shelf x 10
CRS-3 multishelf platform	1152	322 Tbit/s	213.36 x 59.94 x 91.44 dimensions per shelf max. 72+8 shelves in one system

CRS-3

In March 2010, Cisco announced the introduction of the CRS-3 family. The switching capacity of this new product-line is increased more than three times as each switch-fabric line card can process 140 Gbit/s instead of 40 Gbit/s as in the old system. According to Cisco, the current users can upgrade to the CRS-3 system step by step and without serious outage as the chassis, interface-cards, management-systems etc. are the same. The main changes are in the switching-fabric and the option to use new interface modules supporting these higher speeds (14 or 20 × 10 Gb interfaces and 1 × 100 Gb ethernet interface).

As of 2010, some 5000 CRS-1 routers are deployed worldwide.

Cisco claims to have the fastest and highest capacity core routing platform in the world with the CRS-3 platform.

CRS-3 as core in new NextGen IP networks

AT&T tested the CRS-3 in a live-network using the 100 Gb Ethernet backbone and the Dutch telco KPN Telecom selected the CRS-3 platform for their new NextGen IP backbone.

External links

• Cisco CRS-1 & CRS-3
• Cisco CRS-1 & CRS-3 Datasheets
• Cisco IOS XR Software General Information
• Major CRS-1 Deployments
• Source
• Cisco CRS 1 News Release
• Cisco CRS-1 Architecture Inside Analysis(Chinese Version)
• Cisco CRS-3 Press Release
• Cisco says new monster CRS-3 router paves way for more powerful Internet