World Library  
Flag as Inappropriate
Email this Article

Cisco CRS-1

Article Id: WHEBN0004549055
Reproduction Date:

Title: Cisco CRS-1  
Author: World Heritage Encyclopedia
Language: English
Subject: Router (computing), Cisco Systems, Unisys ICON, Cisco IOS, Deutsches Forschungsnetz
Publisher: World Heritage Encyclopedia

Cisco CRS-1

Carrier Routing System or CRS is a modular and distributed core router developed by Cisco Systems Inc that enables service providers to deliver data, voice, and video services over a scalable IP Next-Generation Network (NGN) infrastructure. In a network topology, these routers are generally positioned in the core or edge of a service provider network. They are also used by Over-the-top content providers and large enterprises. It supports a wide range of interface speeds and types such as channelized OC3, OC12 to OC768 on Packet over SONET and from 1GE, 10GE all the way to 100GE on the Ethernet technologies. A standalone CRS-3 system can handle 2.2Tbit/s and a multi-chassis system could be designed to handle 322Tbit/s.


A standalone Carrier Routing System is deployed with a Line card chassis (LCC). The three main functional units of this LCC are the Line cards, Switching fabric and Route processor. The Line card consists of the physical interface card and a modular services card. The physical connectivity could be using Fiber optic cables or using Twisted pair cables. The routing decisions are made by the route processor and the switching fabric takes care of the routing based on the Route processor input. The CRS runs IOS XR which is said to be designed for high-end carrier grade routers and was launched with CRS-1. In a multi-chassis deployment, the Line card chassis is used along with another variety of chassis called as the Fabric Card Chassis (FCC). The architecture enables scalability by increasing the number of Line Card Chassis and/or Fabric Card Chassis. In both single- and multi-chassis configurations, the CRS 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 Fabric Card Chassis, with the S1 and S3 stages resident in the Line Card Chassis.

The CRS Line card chassis comes in three different flavors: 4-slot, 8-slot and 16-slot. The number of slots indicates the number of line cards that the chassis can accommodate. There is only one variety of Fabric card chassis.

4-slot 8-slot 16-slot


Internet service providers
Mobile network operator
Over-the-top content
Wireline services, Service providers – P, PE, Peering
Large Enterprises

Product Portfolio


Cisco Systems Inc has announced the addition of a new product to its existing CRS family, the “Carrier Routing System X,” or CRS-X(C-R-S-Ten), which is expected to be 10 times faster than the first CRS model(CRS-1) the company offered, back in 2004.[1] CRS-X is said to be a 400Gbit/s per slot system and is backward compatible with the previous generation HW. At the time of launch, CRS-X family has three different flavors of physical interface card (40x10GE, 4x100GE and 2x100GE-Flex-40) apart from the improved fabric and modular service cards.

Chassis CRS-X 16 Slot CRS-X 16 Slot:Back-to-Back CRS-X Multi-Chassis
No. of forwarding slots 16 32 Up to 1152
Aggregate Switching Capacity 12.8 Tbit/s 25.6 Tbit/s Up to 921.6 Tbit/s

Cisco states that the CRS-X can be used in back-to-back & multi-chassis deployments and that CRS-1, CRS-3 & CRS-X can co-exist in a multi-chassis setup. The press release (reference) also claims that, the CRS-X 400 GE Line Card with Cisco AnyPort Technology uses Cisco’s CMOS photonic CPAK to reduce power consumption, heat dissipation and increase 100 GE port densities by a factor of three compared to competitive solutions. The Universal Port concept adds the option of using a 100G port as 2 ports of 40G or 10 ports of 10G. 40G can again be used as 4 ports 10G. This product will go up against Juniper Networks’ T4000 and PTX core routing systems and perhaps Alcatel-Lucent’s 7950 XRS.


The CRS-3 is the second generation of the CRS series launched in March, 2010. In CRS-3 each line card slot has a capacity of 140Gbits/s, which is more than three times the capacity of the previous CRS-1 generation. The architecture is retained as in the previous generation and hardware is compatible with the CRS-1 system. Apart from the single-chassis system and the multi-chassis system, CRS-3 supports back-to-back configuration as well. In this configuration, two Line Card Chassis are connected back-to-back and there is no Fabric Card Chassis involved as in the case of a multi-chassis configuration. This configuration works only for the 8-slot and 16-slot chassis models. CRS-3 also supports IPoDWDM. This solution reduces transport elements, while supporting multilayer features such as proactive protection and control plane interaction, reducing operating expenses and capital costs. AT&T Corporation 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.[2]

Model Number of slots Max. Full-Duplex throughput per system Link to product-specs
CRS-3 4 slot
single shelf
4 1.12 Tbit/s Cisco CRS-3 4-Slot Single-Shelf System
CRS-3 8 slot
single shelf
8 2.24 Tbit/s Cisco CRS-3 8-Slot Single-Shelf System
CRS-3 16 slot
single shelf
16 4.48 Tbit/s Cisco CRS-3 16-Slot Single-Shelf System
CRS-3 multishelf platform 1152 322 Tbit/s Cisco CRS-3 24-Slot Fabric-Card Chassis


CRS-1 is the first generation of Carrier Routing System launched in 2004. This replaced the Cisco 12000 routers which were used as core routers. Each slot of CRS-1 has a capacity of 40Gbit/s. CRS-1 supports both standalone and multi-chassis configurations.

Model Number of slots Max. Full-Duplex throughput per system Link to product-specs
CRS-1 4 slot
single shelf
4 320 Gbit/s Interactive presentation CRS-1:4
CRS-1 8 slot
single shelf
8 640 Gbit/s Cisco CRS-1 8-Slot Single-Shelf System
CRS-1 16 slot
single shelf
16 1.2 Tbit/s Cisco CRS-1 16-Slot Single-Shelf System
CRS-1 multishelf platform 1152 92 Tbit/s Cisco CRS-1 24-Slot Fabric-Card Chassis


External links

  • New Cisco core router boasts 10X capacity of original
  • X' Marks Cisco's NewCore-Router Upgrade
  • Cisco Plans To DoubleThe Speed Of The Internet
  • Introduction to CRS - video
  • CRS-3 Video datasheet
  • 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
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.