T H E TOLLY. No September 2002

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1 No September 2002 Dell PowerConnect 3248 versus 3Com SuperStack 3 Switch 4400 and Cisco Systems, Inc. Catalyst 2950 Layer 2 Fast Ethernet/Gigabit Ethernet Switching Competitive Evaluation Premise: Customers who deploy Fast Ethernet/Gigabit Ethernet switches have come to expect high and non-blocking architecture implementations in vendor hardware. In fact, while many customers design networks based upon these expectations, these devices must deliver consistent performance despite configurations in network designs. commissioned The Tolly Group to benchmark the performance of its PowerConnect 3248, an enterprise edge switch. The PowerConnect 3248 provides 48 Fast Ethernet ports and two Gigabit Ethernet ports (built-in copper, optional fiber). Dell also requested that The Tolly Group test the performance of the following two Layer 2 switches: 3Com Corp.'s SuperStack 3 Switch 4400 and Cisco Systems, Inc.'s Catalyst Both devices also provide 48 Fast Ethernet ports and two GBIC slots. Copper GBICs were obtained through normal product distribution channels for use in testing the SuperStack 3 Switch 4400 and the Catalyst The Tolly Group conducted zero-loss tests of bidirectional traffic streams T H E TOLLY G R O U P Test Highlights Test Summary Dell PowerConnect 3248 outperforms the Catalyst 2950 by 47% and the SuperStack 3 Switch 4400 by 30% in Layer 2 tests when forwarding 64-byte frames Dell PowerConnect 3248 delivers an aggregate of 12.3 Gbit/s compared to the Catalyst 2950 at 8.4 Gbit/s and the SuperStack 3 Switch 4400 at 9.8 Gbit/s for 512-byte frames Dell PowerConnect 3248 delivers more than 17.6 million fps for 64-byte frames compared to the Catalyst 2950 at 12 million fps and the SuperStack 3 Switch 4400 at 13.5 million fps Dell PowerConnect 3248 achieves 87% of line rate when handling 64-byte frames, and 91% for both 512-, and 1,518-byte frames Percent of theoretical maximum 100 Layer 2 Zero-Loss Bidirectional Throughput 48 Fast Ethernet, 2 Gigabit Ethernet Ports as Reported by SmartFlow % 91% 91% Dell PowerConnect % 72% 73% 59% 61% 62% 3Com SuperStack 3 Switch 4400 Frame size 64 byte 512 byte 1,518 byte Cisco Catalyst This test bed utilized a configuration in which FE ports 1-10 mapped to the second GbE port (port number 50 or GbE port 2) bidirectionally, FE ports mapped to the first GbE port (port number 49 or GbE port 1) bidirectionally and the remaining 28 FE ports mapped to each other in a full-mesh configuration. Source: The Tolly Group, September 2002 Figure The Tolly Group Page 1

2 of 64-, 512- and 1,518-byte frames in a complex portmapping scheme. Testing was performed in September In accordance with The Tolly Group's Fair Testing Charter (FTC), 3Com and Cisco executives were invited to provide a higher level of technical support for this series of tests. Executives from 3Com accepted the invitation and provided and phone technical support, but Cisco executives did not respond to several invitations. Also, in accordance with The Tolly Group FTC, test results were shared with 3Com and Cisco executives who neither acknowledged nor disputed their accuracy. Test results show that the Dell PowerConnect 3248 offers superior performance to the Catalyst 2950 and the SuperStack 3 Switch 4400 in Layer 2 tests for all frame sizes tested. The PowerConnect 3248 demonstrated near wire-speed performance in all Layer 2 tests of 64-, 512-, and 1,518-byte frames while its competitors were unable to perform at the same packet-loss threshold. Results Zero-Loss Bidirectional Throughput using 64- byte frames Engineers tested the Layer 2 of the devices under test in a complex port-mapping scheme. (See Test Methodology and Configuration section.) In Throughput (Gbit/s) Layer 2 Zero-Loss Aggregate Throughput 48 Fast Ethernet, 2 Gigabit Ethernet Ports as Reported by SmartFlow Dell PowerConnect 3248 tests using 64-byte frames, the 87% of wire-speed or an aggregate of 17,653,354 frames-per-second (fps) whereas the Catalyst 2950 delivered 59% of wire-speed or an aggregate of 12,036,531 fps and the SuperStack 3 Switch 4400 delivered 67% of wire-speed or 13,550,200 fps. (See Figures 1, 3 and 4.) 9.1 Engineers also calculated the actual aggregate (i.e., an aggregate of 13.6 Gbit/s in a full-duplex environment). The results show that the Dell an aggregate of Com SuperStack 3 Switch 4400 Frame size 64 byte 512 byte 1,518 byte Cisco Catalyst This test bed utilized a configuration in which FE ports 1-10 mapped to the second GbE port (port number 50 or GbE port 2) bidirectionally, FE ports mapped to the first GbE port (port number 49 or GbE port 1) bidirectionally and the remaining 28 FE ports mapped to each other in a full-mesh configuration. Source: The Tolly Group, September 2002 Figure 2 Gbit/s. In comparison, the Catalyst 2950 delivered 8.1 Gbit/s and the SuperStack 3 Switch 4400 delivered 9.1 Gbit/s. (See Figure 2.) Zero-Loss Bidirectional Throughput using 512-byte frames Engineers also measured the of the devices under test using 512-byte frames in the same configuration. Test results show that the 91% of theoretical maximum or an aggregate of 12.3 Gbit/s whereas the Catalyst The Tolly Group Page 2

3 delivered 61% of the theoretical maximum or an aggregate of 8.4 Gbit/s and the SuperStack 3 Switch 4400 delivered 72% of the theoretical maximum or an aggregate of 9.8 Gbit/s. (See Figures 1-4.) Zero-Loss Bidirectional Throughput using 1,518-byte frames Finally, engineers tested each device while using 1,518-byte frames in the same configuration. Results show that the 91% of wire-speed or an aggregate of 12.4 Gbit/s whereas the Catalyst 2950 delivered 62% of the theoretical maximum or an aggregate of 8.5 Gbit/s and the SuperStack 3 Switch 4400 delivered 73% of the theoretical maximum or an aggregate of 10.0 Gbit/s. (See Figures 1-4.) Analysis Users that deploy Fast Ethernet/Gigabit Ethernet switches in their networks need to wring every bit of performance from the devices they deploy. In the competitive tests of the PowerConnect 3248 and the Cisco and 3Com switches, the PowerConnect 3248 distinguished itself as the fastest switch tested, providing from 24% to 48% greater than either the Catalyst 2950 or the 3Com SuperStack 3 Switch 4400 when measured across the three frame sizes tested. In the 64-byte frame test, the 46% greater than the Catalyst 2950 and 30% greater than the 3Com SuperStack 3 Switch In the 512-byte frame test the PowerConnect 3248 maintained its performance lead, delivering 48% greater than the Catalyst 2950 and 26% greater than the 3Com SuperStack 3 Switch In the 1518-byte frame test the 47% greater than the Catalyst 2950 and 24% greater than the 3Com SuperStack 3 Switch The message is clear; the PowerConnect 3248 delivers consistent performance gains over the Cisco and 3Com products tested, regardless of frame size. At first glance, the results reported here for the PowerConnect 3248 may seem to contradict results published in a May 2002 Tolly Group Test Summary (Document ), which evaluated the PowerConnect 3248 performance. However, this round of testing utilized a different port-mapping configuration than earlier tests, which accounts for the difference in switch performance between the reports. (See Test Configuration and Methodology section for details.) Dell Computer Corp. PowerConnect 3248 Competitive Evaluation PowerConnect 3248 Product Specifications* Features 13.6 Gbit/s switching capacity 10.1 Mpps maximum forwarding rate 48 Fast Ethernet 10/100 BaseT ports Two 10/100/1000 BaseT ports and two SFP slots (combo ports) Up to 8,000 MAC addresses Auto-Negotiation for speed, duplex, mode and flow control VLAN Support - IEEE 802.1Q tagging and port-based, up to 256 VLANs; dynamic VLANs supported (GVRP) Class of Service - IEEE 802.1p tagging and port-based with 4 priority queues per port; L3/L4 aware prioritization; Weighted-Round- Robin queuing IP Multicast Support - IGMP snooping, static IP Multicast Management - Industry-standard CLI, webbased, SNMPv1, 4 RMON groups and multiple MIBs; dual firmware images supported; configuration files can be uploaded and downloaded from switch Remote Authentication - RADIUS Link Aggregation - LACP and manual as per IEEE 802.3ad Spanning Tree Protocol - IEEE 802.1D Spanning Tree Support IP Address Management - Boot P/DHCP Optional redundant power support with PowerConnect RPS-600 1U, rack-mounting kit included For more information contact: One Dell Way Round Rock, TX Phone: BUY-DELL URL: *Vendor-supplied information not verified by The Tolly Group 2002 The Tolly Group Page 3

4 Related Tests In May 2002, The Tolly Group evaluated the Dell PowerConnect 3248 for bidirectional zero-loss ( 0.001%). The port configuration used for that series of tests differs from the configuration used in current testing. The configuration for previous tests was as follows: Fast Ethernet ports 1-10 forwarded traffic to the first Gigabit Ethernet port and Fast Ethernet ports forwarded traffic to the second Gigabit Ethernet port while the remaining Fast Ethernet ports were mapped to each other in a full mesh configuration (one to many, many to one) using 64-, 512-, and 1,518-byte frames. In that configuration, the PowerConnect 3248 delivered 100% of the theoretical maximum for all frame sizes tested. (See Test Summary ) Test Configuration and Methodology For this series of performance tests, The Tolly Group benchmarked three 48-port Fast Ethernet Layer 2 switches. Each of these switches was additionally outfitted with two Gigabit Ethernet copper interfaces. The switches were: a Dell PowerConnect 3248 version ; a Cisco Systems, Inc. Catalyst 2950G-48 switch version 12.1 (6) EA2a; and a 3Com Corp. SuperStack C17024 version Each device under test was connected to one of the following: a Spirent Communications Frames per second Layer 2 Zero-Loss Aggregate Throughput 48 Fast Ethernet, 2 Gigabit Ethernet Ports 20,000,000 15,000,000 10,000,000 5,000,000 0 SmartBits SMB-6000 Advanced Multiport Performance Tester/Analyzer/Simulator equipped with four LAN-6101A 10/100 SmartModules, which provide total 48 Fast Ethernet ports, and a Spirent Communications SmartBits SMB-600 chassis equipped with one LAN-3301A 10/100/1,000 TeraMetric Ethernet modules, which provide a total of two Gigabit Ethernet copper interfaces. A generic 500-MHz Pentium III PC with 256 Mbytes of RAM was running Spirent Communications SmartFlow version This PC served as the SmartBits console and was running Microsoft Corp. 64 byte 512 byte 1,518 byte Frame size Theoretical maximum Dell PowerConnect Com SuperStack 3 Switch 4400 Cisco Catalyst This test bed utilized a configuration in which FE ports 1-10 mapped to the second GbE port (port number 50 or GbE port 2) bidirectionally, FE ports mapped to the first GbE port (port number 49 or GbE port 1) bidirectionally and the remaining 28 FE ports mapped to each other in a full-mesh configuration. Source: The Tolly Group, September 2002 Figure 3 Windows 2000 Professional, Service Pack 1. For tests, engineers configured a test bed in which the first 10 Fast Ethernet ports of the device under test forwarded traffic to the second Gigabit Ethernet port (port number 50) bidirectionally, the Fast Ethernet ports to the first Gigabit Ethernet port (port number 49) bidirectionally and the remaining 28 Fast Ethernet ports were destined for each other in a full mesh configuration. (See Figure 5.) Each device under test was configured for maximum speed (100 Mbit/s for Fast Ethernet ports and 1,000 Mbit/s for 2002 The Tolly Group Page 4

5 Fast Ethernet / Gigabit Ethernet Full-duplex Layer 2 Performance Summary Maximum theoretical (full duplex, Gbit/s) Frame size (bytes) Maximum theoretical (frames-per-second) Actual (full duplex, Gbit/s) Actual (frames-persecond) Percent of theoretical maximum Dell Computer PowerConnect 3248 Layer 2 Switch - 48 Port Fast Ethernet & 2 Port Gigabit Ethernet ,238, ,653,354 87% 512 3,195, ,896,625 91% 1,518 1,105, ,006,568 91% 3Com Corporation SuperStack Layer 2 Switch - 48 Port Fast Ethernet & 2 Port Gigabit Ethernet ,238, ,550,200 67% 512 3,195, ,306,160 72% 1,518 1,105, ,395 73% Cisco Systems Catalyst 2950G-48 Layer 2 Switch - 48 Port Fast Ethernet & 2 Port Gigabit Ethernet ,238, ,036,531 59% 512 3,195, ,961,919 61% 1,518 1,105, ,005 62% Source: The Tolly Group, September 2002 Figure 4 Gigabit Ethernet ports) and full-duplex operation while Spanning Tree, Flow Control and all other ancillary functions were disabled. For bidirectional steady state, zero-loss ( 0.001%) tests of 64-, 512-, 1,518-byte frames, engineers used SmartBits to generate Layer 2 traffic in the configuration described above at an initial load of 50%. Tolly engineers initiated each test and recorded results. If frame loss exceeding the test threshold occurred, the offered load was adjusted by 1% and engineers ran the test again until there was no frame loss. The SmartFlow application recorded total transmitted frames and total received frames, plus frame loss, if any. Tests were run for 60 seconds for each of three test iterations and results were averaged. Equipment Acquisition and Support Both the Cisco Catalyst 2950 and 3Com SuperStack 3 Switch 4400 were acquired through normal product distribution channels. In accordance with The Tolly Group's "Fair Testing Charter", The Tolly Group contacted executives at Cisco and 3Com and invited them to provide a higher level of support than available through normal channels. Cisco executives did not respond to several invitations from The Tolly Group. Executives from 3Com agreed to provide a higher level of support than normally offered through channels. Results were shared with executives from Cisco and 3Com, who neither acknowledged nor disputed their accuracy The Tolly Group Page 5

6 Test Bed Source: The Tolly Group, September 2002 Figure 5 The Tolly Group gratefully acknowledges the providers of test equipment used in this project. Vendor Product Web address Spirent Communications SmartBits 600 Chassis Spirent Communications SmartBits 6000 Chassis Spirent Communications SmartBits LAN-3301A Spirent Communications SmartBits LAN-6101A Spirent Communications SmartFlow v Tolly Group Services With more than a decade of testing experience of leading-edge network technologies, The Tolly Group employs time-proven test methodologies and fair testing principles to benchmark products and services with the highest degree of accuracy. Plus, unlike narrowly focused testing shops, The Tolly Group combines its vast technology knowledge with focused marketing services to help clients better position product benchmarks for maximum exposure. The company offers an unparalleled array of reports and services including: Test Summaries, Tolly Verifieds, performance certification programs, educational Webcasts, white paper production, proof-ofconcept testing, network planning, industry studies, end-user services, strategic consulting and integrated marketing services. Learn more about The Tolly Group services by calling (732) , or send to info@tolly.com. For info on the Fair Testing Charter, visit: Project Profile Sponsor: Dell Corp. Document number: Product Class: Layer 2 Fast Ethernet/Gigabit Ethernet switches Products under test: Dell PowerConnect 3248, version Cisco Systems Catalyst 2950, version 12.1 (6) EA2a 3Com SuperStack 3 Switch 4400, version 2.02 Testing window: September 2002 For more information on this document, or other services offered by The Tolly Group, visit our World Wide Web site at send to info@tolly.com, call (800) or (732) Internetworking technology is an area of rapid growth and constant change. The Tolly Group conducts engineering-caliber testing in an effort to provide the internetworking industry with valuable information on current products and technology. While great care is taken to assure utmost accuracy, mistakes can occur. In no event shall The Tolly Group be liable for damages of any kind including direct, indirect, special, incidental, and consequential damages which may result from the use of information contained in this document. All trademarks are the property of their respective owners. The Tolly Group doc rev. kco Oct The Tolly Group Page 6