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Network Migration from Shared Ethernet to Switched Ethernet. Cisco Systems Confidential. 0661_03F7_c3. 1. Juan A. Munguia. Consulting Engineer. Cisco Systems Confidential. 0661_03F7_c3. 2. Agenda. Driving Forces LAN Switching Benefits High-Speed Alternatives Switching Considerations
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Network Migration fromShared Ethernet to Switched Ethernet Cisco Systems Confidential 0661_03F7_c3 1
Juan A. Munguia Consulting Engineer Cisco Systems Confidential 0661_03F7_c3 2
Agenda • Driving Forces • LAN Switching Benefits • High-Speed Alternatives • Switching Considerations • Migration Case Studies
The Desktop vs. the Network NetworkBandwidth MIPS • Performance increases in the processing power of PCs is doubling every 18 months • Bus improvementshave evolved rapidly • Networking hardwareevolves more slowly than PCs 10 Mbps Source: Intel
New Peer-to-Peer Traffic • Distributed systems have forced an increase in server-to-server communications • Growth of desktop-to-desktop video, interactive applications and intranets
10/100BaseT Installed 100BaseT in Use New NIC Installations • NICs purchased are commonly 10/100 • Excess capacity allow users to explore new applications • 100M is limited by 10BaseT switches and hubs
Network Traffic—Changing the Rules “The New 80–20 Rule” 80% Backbone • Server locations shifting • Server bandwidth performance increase • Latency reduction required • Multimedia applications • Multicast applications • Price/performance improvements required 20% 20% 80% Workgroup
All Other Ethernet Ethernet Dominance • Why Ethernet dominance? • Scalability 10/100/1000 • Smooth migration • Network reliability • Network management tools and techniques • Low cost Dominance will Continue 1996 Shipments 1996 Installed Base Source: IDC
Agenda • Driving Forces • LAN Switching Benefits • High-Speed Alternatives • Switching Considerations • Migration Case Studies
The Switching Revolution Building BackboneFast Ethernet between Floors and in the Building Data Center Campus BackboneFast Ethernet between Buildings and in the Central Data Center 10 Mbps 10/100 Mbps 100 Mbps 100 Mbps 10/100 Mbps CentralSwitch WAN WAN Cisco Systems Confidential 0661_03F7_c3 10
Why Ethernet Switching? • Eliminates collisions • Increases bandwidth • Facilatates network control • Enables cost-effective migration to high-speed technologies • Matches traffic profiles
CRASH Shared Resource • Excess Ethernet collisions • Sluggish network response • Increasing user complaints
Switched Resource • Collision-free Ethernet • Quick network response • Increased user productivity
A B C D Bandwidth Multiplier • Total bandwidth is 10 Mbps • Theoretical bandwidth is2.5 Mbps per host • Effective bandwidth <1 Mbps per host • Communication is half-duplex • Only one host at timemay transmit • There will be contentionfor bandwidth
A B C D Bandwidth Multiplier—HDX • Total bandwidth is 40 Mbps • Theoretical bandwidth is5 Mbps per host • Effective bandwidth ~2-3 Mbps • Multiple hosts can transmit at the same time • Little contention for bandwidth • Contention for switch resources
A B C D Bandwidth Multiplier—FDX • Total bandwidth is 40 Mbps • Average bandwidth is10 Mbps per host • Multiple hosts can transmit at the same time • No contention for bandwidth • Contention for switch resources
Control to the Administrator • Shared Ethernet is inherently fair • 100% fairness not necessarily good • Some users are more important than others (VP vs. Secretary) • Switching can allow prioritization, multicasting, security, etc. PER USER
Control to the Administrator • Per user visibility into switched network • Switch is capable of applying advancedpolicy (e.g. VLANs) • Traffic management features available on switch (broadcast suppression) • Security, multicasting, prioritization canbe implemented Sally VP Joe User SuperServer Cisco Systems Confidential 0661_03F7_c3 18
Cost-Effective Switching to Higher Speeds • Preserves wiring investment • Preserves NIC investment • Preserves management infrastructure • Preserves installed application base • Allows for smooth migration
Traffic Profiles—Symmetric • Provides switching between like bandwidths(10/10 Mbps or100/100 Mbps) • Suited forpeer-to-peer traffic 10 Mbps 10 Mbps 100 Mbps 10 Mbps
Traffic Profile—Asymmetric • Provides switching between unlike bandwidths(10/100 switching) • High bandwidth where needed • Ideal for client-server traffic 10 Mbps 10 Mbps 100 Mbps 10 Mbps
Agenda • Driving Forces • Lan Switching Benefits • High-Speed Alternatives • Switching Considerations • Migration Case Studies
What Is Fast Ethernet? • IEEE 802.3u standard (June 1995) • Evolved from 10 Mbps Ethernet • Star topology (No baseband option) • http://www.alumni.caltech.edu/~dank/fe/
Cabling Support 100 Mbps MAC (Media Access Control) 802.3 CSMA/CD Ethernet MII (AUI Equivalent) 100BaseTX 2-Pair CAT5 2-Pair STP 100BaseT4 4-Pair CAT3 4 and 5 UTP 100BaseFX MultimodeFiber
100BaseTX 100BaseTX Client Repeater Pair 1 Pair 1 Pair 2 Pair 2 • 4B/5B, MLT3 signaling scheme • 125 Mbps on wire/100 Mbps effective data rate • 100 meter distance • Supports 2-pair category 5 wiring • Same pinout and connectors as 10BaseT • Optional auto-negotiation (10/100 Mbps) • Physical layer is full-duplex capable
100BaseT4 100BaseT4 Client Repeater Pair 1 Pair 2 Pair 3 Pair 4 Pair 1 Pair 2 Pair 3 Pair 4 • Supports 4-pair category 3,4,5 wiring • Pairs 1,2 like 100BaseTx • Pairs 3,4 bi-directional • 33.3 Mbps per pair data rate, 25 Mhz clocking, tri-state 8B6T • Supports auto-negotiation • No full-duplex support • 100 meter distance
Strand 1 Strand 1 Strand 2 Strand 2 100BaseFX 100BaseFX • Multimode fiber using SC (preferred), MIC and ST connectors • 4B5B and NRZI signaling scheme • 125 Mbps on wire/100 Mbps data rate • Maximum fiber length is 412 meters (half duplex) and 2000 meters (full duplex) Switch Client
Repeater Repeater Repeater DTE DTE DTE DTE 100BaseT Repeaters Only one Class-1 repeater in asingle-collision domain usingmaximum cable length Class 1 Class 2 Two Class-2 repeaters in a single-collision domain using maximum cable length
Maximum Collision Domain Copperand Fiber (TX and FX)* Model Copper Fiber DTE-DTE (No Repeater) 100 412 N/A 260 One Class 1 Repeater 200 272 One Class 2 Repeater 308 320 200 Two Class 2 Repeater 228 205 216 *Note: Assumes 100m of copper cable and one fiber link
NIC NIC NIC NIC NIC NIC Fast Ethernet Topology Bridge or Router 200m (308 m with Fiber) 200 (308 m withFiber) 100 m (208m withFiber) 100 m (208m withFiber) Repeater Repeater 100m 100m 100m 100 m 100 m 100 m
NIC NIC NIC NIC NIC NIC NIC NIC NIC NIC NIC NIC Fast Ethernet Topology 400m (2 km Full-Duplex Fiber) Switch Switch 100m 100m 100m 100m 100m 100m 100BT 100BT 100BT 100m
Auto Negotiation I detect on port 1 100 Mbps full duplex connection. I will set port 1 to 100 Mbps full duplex I detect on port 20 10 Mbps half duplex. I will set port 20 to 10 Mbps half duplex 1 20 FLP 100BaseT FLP NIC NIC
Full Duplex • Switch, router, or adapter interface; not a repeater • 100BaseT4 half duplex only • Maximum distance: 100 meters • 100BaseTX half and full duplex • Maximum distance: 100 meters • 100BaseFX half and full duplex • Half duplex: 400 meters • Full duplex: 2000 meters
What Is Gigabit Ethernet • IEEE 802.1z working group • Today still not a standard! • Evolved from 10/100 Ethernet • Star topology • 1000 Mbps data rate • http://www.gigabit-ethernet.org/
Cabling Support 1,000 Mbps MAC (Media Access Control) 802.3z CSMA/CD Ethernet GMII (AUI Equivalent) 1000BaseX Copper STP/UTP Category 5 UTP 25m 1000BaseX Copper STP/UTP Category 5 UTP 100m 1000BaseX MultimodeFiber 500m 1000BaseX SinglemodeFiber 3 km Note: Distances are IEEE 802.3z goals
Gigabit Ethernet—Shared Topology (Copper and Fiber) 125m (200m with Fiber) (200m Long-Termwith Copper) 125 m (200m with Fiber) (200m Long-Termwith Copper) Switch or Router Existing Network 100m Fiber 100m Fiber Repeater Repeater Copper 25m 25m 25m 25m 25m 25m Copper NIC NIC NIC NIC NIC NIC Note: 100m on Copper long-term
Switch or Router Full-Duplex 500m Multimode Fiber 3 km Singlemode Fiber Switch Switch Full-Duplex Multimode Fiber Copper 25m 25m 25m 500m 500m 500m 100BT Switch 100BT Switch 100BT Switch NIC NIC NIC 100M* UTP NIC NIC NIC NIC NIC NIC NIC NIC NIC *Note: 100m on copper long-term Gigabit Ethernet—Switched Topology
Gigabit Ethernet Timing Production Products Pre-Standard Products Interop Testing ’98 ’95 ’96 ’97 By ’98—CompleteStandard Nov. ’95—IEEE 802.3 CommissionsHigh-Speed Study Group Mid ’97—Start 802.3Working Group Ballot July ’96—IEEE 802.3zGigabit Ethernet Task Force Created End ’96—Basic Concept Agreement
Fast Ethernet Futures • Gigabit Ethernet of course • 802.1q for virtual LANs • 802.1p for priority and Layer 2 multicast • 100BaseT2 (Category 3 cabling) • 1000BaseX at 100m
ATM Comparisons • Circuit switched vs. packet switched • Overlay non-broadcast media access network • Service integration and QOS • Signaling scalability • Encapsulation and “cell tax” • Cost
1 S2 S6 S2 S6 1 1 S3 S5 S8 S8 S1 S1 VC S3 S5 2 2 S4 S7 S4 2 S7 Circuit Switched vs. Packet Switched Connectionless:Packet Routing Connection Oriented:Circuit Routing • Path 1 = S1, S2, S6, S8 • Path 2 = S1, S4, S7, S8 • Each data packet can follow a different path • Packets can arrive out of sequence at destination S8 • VC = S1, S4, S7, S8 • All data follows same path • Packets arrive always in sequence at destination S8
Overlay NBMA Network ATM Addresses Router orSwitch Router orSwitch • Multiple layers of addressing • Requires address resolution • Other examples: • X25 networks • Dial-up networks ATM Network Ethernet Ethernet Direct-Attached Stations IP Addresses,MAC Addresses
Service Integration and QOS Workgroup ATM Campus/MAN ATM Multiservice WAN ATM Telco/ISP
Scalability Connect to B • Dynamically set up connections via signaling • High CPU requirements • Requires complex routing protocol Yes/No UNI NNI ATMA NNI Signaling UNI Signaling NNI Connect to B UNI ATM Switches Yes/No ATMB
Encapsulation and Cell Tax User Higher Layer User Information Encapsulation Header (RFC 1483, LANE) User Information AAL 5 Layer User Information+Header Pad AAL5 Trailer … ATM Layer ATM hdr (5) Payload (48) ATM hdr (5) Payload (48)
Agenda • Driving Forces • LAN Switching Benefits • High-Speed Alternatives • Switching Considerations • Migration Case Studies
Switching Considerations • Switch operation • Broadcast containment • Management • Host issues • Quality of service and multicasting
A From: A B LAN Switch Operation • Forwards packets based on a forwarding table • Operates at OSI Layer 2 • Forwards based on the MAC (Layer 2) address • Hardware (ASIC) based • Advanced buffering • Complex lookup algorithms Application Presentation Session Transport Network Data Link Data Link
A B LAN Switch Operation How a LAN Switch Learns Addresses • Learns a station’s location by examining the source address • Sends out all ports (except the port that the frame entered from) when the destination address is a broadcast, multicast, or an unknown address • Forwards when the destination is located on a different interface • Filters when the destination is located on the same interface 10 Mbps 2 1 Data To: A 10 Mbps Interface 4 1 2 3 4 A Stations B C Cisco Systems Confidential 0661_03F7_c3 55
Multilayer LAN Switch Layer 2 MacAddresses Layer 3Network • Switching and filtering basedon the Layer 2 (bridging) and Layer 3 (routing) address • Combines ease of use andLayer 2 switching withsecurity and stabilityof Layer 3 switching • Imbedded Routers vs Layer 3 switching engine } } DA SA IP