Chassis Architecture Brandon Wagner Office of Information Technology Infrastructure Design Solutions

Who Am I? BS, Information Technology Work for BYU OIT - 5 years (2 part-time, 3 full-time) Primary Responsibilities: Cisco NAC / Wireless Packetshaping Packet Analysis Data Center Design New Construction Design Secondary Responsibilities: Firewalls Routing/Switching QoS Network Security A Cisco guy (for Ekstrom)

What do you know?

Lecture Series October 5th October 7th October 12th October 14th Chassis Architecture October 7th Chassis Demo & Convergence/Virtualization October 12th Routing Protocols Evolution of BYU Campus Routing October 14th MPLS Review Email: brandon_wagner@byu.edu

Learning Outcomes Understand the need for a chassis style switch. Components of a Chassis switch. Two types of backplane connectivity. Two methods of forwarding traffic within a chassis.

Scenarios A sysadmin has three clusters of 48 servers in a data center. They need low latency, high bandwidth connectivity between them. How do you do it? A service provider is building out their core infrastructure. They need gigabit Ethernet ports, Optical carrier ports, and T1 ports. They need all of them to be able to talk to each other. How do you do it?

The Chassis Switch Chassis - Frame of switch, provides slots for line cards and supervisors, fan tray, power supplies Backplane – Connects all modules together. Supervisor - Central CPU for switch Line Cards - Provide ports for edge or feed connections Power Supplies – Provide power for line cards, supervisors Cisco 6509 Chassis Brocade FastIron SX

Why the Chassis? Flexibility Bandwidth Port Density Service modules – firewalls, wireless controllers, NAMs Bandwidth Inter-switch bandwidth. Greater than 100Mb or 1Gb. Ports aren’t used for up-links. Port Density A 13 slot chassis can support up to 528 gigabit Ethernet ports. Centralized Intelligence and Management

Chassis Basic Chassis Fan Tray Cost: $2,000 - $7,000 35 – 70 CFM per slot Pulls air instead of pushing air out. Cost: $2,000 - $7,000

Backplane Shared Bus Switch Fabric Provides shared bandwidth to all cards. One connection at a time Integrated into Chassis Ex: Cisco 6500 – 32Gbps shared Switch Fabric Dedicated bandwidth between slots/cards. Full Duplex Standalone line card or integrated into Supervisor Ex: Cisco 6500 – 16 or 40 Gbps

Supervisor MFSC – Multilayer Switch Feature Card Switch Fabric RP – Route Processor SP – Switch Processor Switch Fabric Provides 16 or 40Gbps 400 Mpps PFC – Policy Feature Card MAC Table Routing/Forwarding Table ACL/QoS Management Panel Cost: $20,000 to $60,000 each

Line Cards Various ports of Wire speed vs shared 10/100/1000 Ethernet Gigabit Fiber Ethernet 10 Gigabit Ethernet DSx, OCx, T1, T3 Wire speed vs shared ASIC – Application Specific Integrated Circuit Centralized vs Distributive Forwarding Cost: $4,000 – 45,000

Power Supplies Output ranges Provides power to: Cost: $1,000 – 8,000 950W to 8700W per supply Provides power to: Supervisor Line cards (functionality) Line cards (PoE) Fan tray Cost: $1,000 – 8,000

Centralized Forwarding Forwarding process: Packet header (not data payload) is sent over the bus Supervisor examines packet and determines forwarding decision Supervisor sends decision over bus Line card then sends full payload over fabric to destination ASIC Central because all forwarding decisions are centralized in the supervisor.

Distributive Forwarding Requires line card to have a DFC Forwarding Process: Routing/Forwarding config is pushed to DFC on line card. When packet enters linecard, a decision is made locally. Data is forwarded over fabic. No Bus interaction Distributive because all forwarding decisions are distributed among each line card.

Case Study Fabric Utilization Methods in a Cisco 6500 Classic Centralized forwarding All traffic traverses the shared bus. CEF256 (2x8 x 8 x 2) Bus and Fabric (8Gbps) connection. dCEF256 Distributed forwarding Fabric (8Gbps) connection only. CEF720 (2x20 x 9 x 2) Bus and Fabric (20Gbps) connection. dCEF720 Fabric (20Gbps) connection only. dCEF256 CEF256 dCEF720 CEF720

Chassis Design at the Edge Backplane’s are now being used in Edge Switches. Stacking Cables daisy chain switches together Example: Cisco 3750 Provides 32 Gbps shared bus. New 3750-E Series provides 64 Gbps bus.

Pro’s and Con’s Pro’s Con’s Others? Able to manage hundreds of ports via one management interface. Very fast backplane for local switching Doesn’t require using physical ports for switch to switch connectivity. Con’s Expensive. Price per port higher for initial deployment. Greater outage experienced when there is a failure. Others?

Questions?

Chassis Around Campus TNRB Building Router JKB Building Router ITB Building Router