Cabletron Systems Inc. SmartSwitch 9000 Token Ring Switching in Heterogeneous Networks

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1 1R 7 + ( 72//< * DQXDU\ Cabletron Systems Inc. SmartSwitch 9000 Switching in Heterogeneous Networks Test Summary & abletron Systems Inc. commissioned The Tolly Group to benchmark the SmartSwitch The Tolly Group examined the SmartSwitch 9000 s translational switching capabilities in a heterogeneous network (, Fast Ethernet, FDDI, and Ethernet), across a backbone technology (ATM), and in homogeneous environments. The Tolly Group tested the frame handling capabilities of the Smart- Switch 9000 in these environments, as well. Testing was performed in December 1997 and January Test results show that the SmartSwitch 9000 delivers wire-speed performance across multiple streams of traffic while performing translational switching between and Fast Ethernet, FDDI, and Ethernet with frame sizes of 512 bytes and larger. Even switching traffic across an ATM backbone, the SmartSwitch 9000 hit usage rates as high as 96.51% of the target media. Transferring data between native LANs, the SmartSwitch 9000 delivered wire-speed performance utilizing up to 99.7% of the target networks. Additionally, the SmartSwitch 9000 demonstrated its frame forwarding capacity, transporting an aggregate of 199,309 frames per second (fps) between networks when eight simultaneous intra-module streams of traffic were offered as input load (an average of 24,914 fps per stream) on a fully-utilized 16-port module. It is important to note that even though RMON was active during testing, the SmartSwitch 9000 did not suffer performance degradation. All LANs were configured at 16 Mbit/s and supported source route Test Highlights The SmartSwitch 9000 delivers high-performance translational bridging. The SmartSwitch 9000 effectively utilizes high-speed backbone technologies like ATM to interconnect networks. The SmartSwitch 9000 offers near wire-speed performance within native environments. Translational Switching Aggregate Throughput to Fast Ethernet (Seven Streams of Traffic) Source: The Tolly Group, January 1998 Figure 1 bridging, while the Fast Ethernet, FDDI, and Ethernet LANs were configured to employ transparent bridging. The Tolly Group used 512-, 1,024-, 1,518-, and 3,972-byte frame sizes for performance testing and 64- byte frames for frame capacity testing ,024 1,518 Frame generators were used to supply traffic to the system under test. While Gigabit Ethernet was not tested, it was included in the 1997 Industry Study (see

2 7KH7ROO\*URXS &DEOHWURQ6\VWHP 6PDUW6ZLWFK 7HVW5HVXOWV 7RNHQ5LQJ6ZLWFKLQJLQ +HWHURJHQHRXV 1HWZRUNV Many campus networks today consist of a conglomeration of different LAN technologies. Network managers often require transparent connectivity among LANs of different types. The goal of these three tests was to measure how much throughput the SmartSwitch 9000 can deliver when performing translational switching between LANs in a heterogeneous network. Towards that end, The Tolly Group conducted steady state throughput testing of the SmartSwitch 9000 when forwarding traffic from to Fast Ethernet, FDDI, and Ethernet networks. 7RNHQ5LQJWR)DVW (WKHUQHW The Tolly Group benchmarked the steady-state throughput of the SmartSwitch 9000 when forwarding traffic from seven input ports to a single Fast Ethernet output port. Input traffic was load balanced and the aggregate offered load did not exceed Fast Ethernet s maximum capacity of 100 Mbit/s. The SmartSwitch 9000 delivered wire speed performance for all frame sizes tested (see figure 1). These results demonstrate that when performing translational switching between source-routed and Fast Ethernet LANs, the SmartSwitch 9000 is capable of fully utilizing the target LAN. 7RNHQ5LQJWR)'', The Tolly Group benchmarked the steady-state throughput of the SmartSwitch 9000 when forwarding traffic from seven input ports to a single FDDI output port. Input traffic was load balanced and the aggregate offered load did not exceed FDDI s maximum capacity of 100 Mbit/s. The SmartSwitch 9000 successfully translated and forwarded seven simulta- Translational Switching Aggregate Throughput to FDDI (Seven Streams of Traffic) % 99.77% 99.77% 99.81% 512 1,024 1,518 3,972 Source: The Tolly Group, January 1998 Figure 2 Translational Switching Aggregate Throughput to Ethernet (One Stream of Traffic) ,024 1,518 Source: The Tolly Group, January 1998 Figure 3

3 7KH7ROO\*URXS &DEOHWURQ6\VWHPV 6PDUW6ZLWFK neous streams of traffic from to FDDI. Figure 2 shows that the SmartSwitch 9000 came within a hair of fully utilizing the target FDDI LAN, achieving throughput of 99.77% to 99.81% utilization. 7RNHQ5LQJWR(WKHUQHW The Tolly Group benchmarked the steady state throughput of the Smart- Switch 9000 when forwarding traffic from a single input port to a single Ethernet output port. Offered load did not exceed Ethernet s maximum capacity of 10 Mbit/s. Test results show that the Smart- Switch 9000 fully utilized the Ethernet LAN. Figure 3 shows the Smart- Switch 9000 successfully achieved throughput for all frame sizes tested, translating traffic from to Ethernet format. $DFNERQH6ZLWFKLQJ While many network managers look to a switch to interconnect various LANs to share resources and users, they also demand a device that can effectively utilize backbone technologies. With this in mind, The Tolly Group benchmarked the steady-state switching throughput of the SmartSwitch 9000 when forwarding 10 streams of traffic between switches interconnected by an ATM uplink running at a 155 Mbit/s OC-3 rate. Test results demonstrate that the SmartSwitch 9000 is capable of transporting 512-byte frame traffic over ATM to the target LAN, while utilizing up to 96.51% of the target. Target utilization drops slightly with the other frame sizes tested, but never dropped below 82.27% utilization (see figure 4). 7RNHQ5LQJ6ZLWFKLQJ For customers who maintain a single LAN topology across their enterprise, the switching throughput in a pure token ring environment is of paramount importance. The Tolly Group benchmarked the steady-state throughput of the SmartSwitch 9000 when forwarding source-routed traffic between LANs. When forwarding two streams of large frame size traffic, the Smart- Switch 9000 utilized 99.7% of the destination LANs. Even with small 512-byte frames, output LAN utilization reached 96.86% (see figure 5). These results demonstrate that the SmartSwitch 9000 provides legacy users with the near-wire-speed switching throughput they require, while also offering them the option to integrate heterogeneous networks as needs arise. Additionally, the SmartSwitch 9000 provides linear throughput as additional traffic streams are added. Figure 6 shows that with the largest frames tested (3,972 bytes), the percent utilization of the output s remained constant for 2, 4, 6, and 8 streams of traffic. With 1,024- byte frames, utilization dropped slightly from 98.46% with two streams, to 98.38% with eight streams. With smaller 512-byte frames, utilization dropped slightly from 96.86% to 96.79%. Since the drop in utilization is insignificant in both cases, throughput can be considered linear. )UDPH+DQGOLQJ&DSDFLW\ The Tolly Group benchmarked the SmartSwitch 9000 s frame forwarding capacity when forwarding 64- byte frames between a heterogeneous network, a homogenous network, and across the ATM backbone. (Note: 64-bytes is the smallest legal frame size for Ethernet and is typically the frame size chosen when evaluating the frame handling characteristics of an internetworking device.) The SmartSwitch 9000 exhibited an aggregate frame forwarding capacity of up to 152,434 fps when transporting seven streams within a heterogeneous network (an average of 21,776 fps per port). The SmartSwitch 9000 forwarded an aggregate of 143,395 fps (an average of 14,340 fps per port) across 10 streams on the ATM backbone. Transporting eight streams between networks, the SmartSwitch 9000 forwarded Cabletron Systems Inc. SmartSwitch 9000 Translational Switching Performance Cabletron Systems, Inc. SmartSwitch T Product Features* Enables users to share resources such as servers and printers between and Ethernet, Fast Ethernet, FDDI and ATM via any-to-any switching Protects existing investment, while enabling users to mix and match technology based on business requirements Superior scalability through distributed switching architecture, eliminating single point of failure Supports both Transparent and Source Routed environments through translational switching Choice of Gigabit Ethernet, ATM, Fast Ethernet or FDDI high-speed uplinks Superb performance through a nonblocking switching design connecting to the 2.5 Gbit/s INB SmartSwitch 9000 backplane Standards-based, full-duplex capable IEEE 802.5r switching ports with support for directly-attached stations Scales from 16 to 112 separate segments in a single SmartSwitch 9000 chassis Standards-based SNMP management, including MIB II and RMON per port Supports protocol translation for TCP/ IP, IPX, AppleTalk, SNA and NetBIOS *Vendor-supplied information not verified by The Tolly Group 199,309 fps (an average of 24,914 fps per port). See figure 7.

4 7KH7ROO\*URXS &DEOHWURQ6\VWHP 6PDUW6ZLWFK 7HVW&RQILJXUDWLRQ DQG0HWKRGRORJ\ 6\VWHP8QGHU7HVW &RQILJXUDWLRQDQG 5HYLVLRQ/HYHOV Two SmartSwitch 9000s were used during testing. One switch was outfitted with a 16-port module, a two-port ATM module, a twoport dual-attached station (DAS) FDDI module and a 12-port 10/100 Fast Ethernet module. The other switch was outfitted with a 16-port module, a two-port ATM module and a 36-port Ethernet module. The SmartSwitch 9000s token ring modules were configured with all ports in Source Route Bridging mode, set to 16 Mbit/s half duplex (HDX), and configured with IPX translation enabled. The Fast Ethernet module was configured to autosense media speed and set to HDX. The FDDI module was configured to operate in DAS mode using translational bridging. The Ethernet module was configured for 10 Mbit/s HDX. The ATM modules were configured with a single PVC (a single VPI/VCI pair). Note: ATM served as a pipe running neither LANE nor any RFCdefined protocol. For Switching in Heterogeneous Networks and ATM Backbone Switching tests, all traffic flowed inter-module meaning it entered and exited the switch under test through different switch modules. For Switching tests, all traffic flowed intra-module meaning it entered and exited the switch under test through the same switch module. Part numbers, hardware, software, and bootprom revision levels, of the systems under test are listed in figure 8. 7HVW%HG'HVFULSWLRQ 7UDQVODWLRQDO6ZLWFKLQJ All input traffic consisted of valid source-route-bridged IPX frames. The Tolly Group validated Backbone Switching Aggregate Throughput to via ATM (10 Streams of Traffic) % 82.27% 83.68% 84.74% 512 1,024 1,518 3,972 Source: The Tolly Group, January 1998 Figure 4 Switching Aggregate Throughput to (Two Streams of Traffic) % 98.46% 99.05% ,024 1,518 3,972 Source: The Tolly Group, January 1998 Figure 5

5 7KH7ROO\*URXS &DEOHWURQ6\VWHPV 6PDUW6ZLWFK Switching Aggregate Throughput (Load Comparison) Generated Number of Simultaneous Traffic Streams Frame Size Two Four Six Eight (bytes) Mbit/s Percent Utilization Mbit/s Percent Utilization Mbit/s Percent Utilization Mbit/s Percent Utilization % % % 1, % % % % 1, % % % 3, Source: The Tolly Group, January 1998 Figure 6 Test Environment Aggregate Frame Handling Capabilities (64-byte Frames) Number of Simultaneous Traffic Streams Aggregate Throughput (fps) to Fast Ethernet 7 148,809 to FDDI 7 152,434 to Ethernet 1 14,881 to via ATM uplink ,395 to 8 199,309 Source: The Tolly Group, January 1998 Figure 7 Chassis Number 1 2 Hardware and Software Revision Levels Description Part Number Hardware Revision Software Revision BootPROM Revision SmartSwitch C106 N/A N/A N/A Management 9C306 0DB T h ATM 9A C Gigabit Ethernet 9G FDDI 9F DA Fast Ethernet 9H A SmartSwitch C106 N/A N/A N/A Management 9C306 0DB T h Gigabit Ethernet 9G ATM 9A C Ethernet 9E C Source: The Tolly Group, January 1998 Figure 8 the frames at both the input and the output of the systems under test. For the -to-fast Ethernet tests, seven LANs served as the input to the device under test and one Fast Ethernet LAN served as the output. Attached to each input LAN, a Wandel & DominoLAN DA-320 (analyzer version 2.2) generated, measured, and recorded the input traffic. Attached to the output LAN, a DominoLAN DA-350 (analyzer version 2.2 patch 1) measured and recorded the output traffic, and a Network General Expert Sniffer (version 4.80) decoded frame protocols (see figure 9).

6 7KH7ROO\*URXS &DEOHWURQ6\VWHP 6PDUW6ZLWFK Translational Switching to Fast Ethernet (Seven traffic streams) Fast Ethernet Seven Wandel & (each DominoLAN is connected to a single LAN) Seven s (each LAN is connected to a single switch port) Cabletron Systems Inc. SmartSwitch 9000 One Wandel & DominoFastEthernet DA-350 Network General Corp. Expert Sniffer Network Analyzer to FDDI (Seven traffic streams) FDDI Seven Wandel & (each DominoLAN is connected to a single LAN) Seven s (each LAN is connected to a single switch port) Cabletron Systems Inc. SmartSwitch 9000 One Wandel & DominoFastEthernet DA-330 to Ethernet (One traffic stream) Ethernet One Wandel & DominoLAN DA-320 (connected to a single LAN) One (connected to a single switch port) One Wandel & DominoFastEthernet DA-320 Network General Corp. Expert Sniffer Cabletron Systems Inc. SmartSwitch 9000 Network Analyzer Source: The Tolly Group, January 1998 Figure 9 For the -to-fddi tests, the input side of the system was identical to the input used for the to Fast Ethernet tests. An FDDI LAN hung off the output side of the net. Attached to the output LAN, a DominoFDDI DA-330 (analyzer version 2.2) measured and recorded, the output traffic (see figure 9). For the -to-ethernet tests, a single LAN served as the input and a single Ethernet LAN served as the output. Attached to the input LAN, a DominoLAN (analyzer version 2.2) generated, measured, and recorded input traffic. Attached to the output LAN, a second DominoLAN (analyzer version 2.2) measured and recorded the output traffic (see figure 9). %DFNERQH6ZLWFKLQJ For the -to- via ATM tests, 10 LANs served as the input for the test bed and 10 LANs served as the output. Two SmartSwitch 9000s interconnected via ATM OC-3 served as the systems under test. Attached to each input LAN, a DominoLAN DA- 320 (analyzer version 2.2) generated,

7 7KH7ROO\*URXS &DEOHWURQ6\VWHPV 6PDUW6ZLWFK Backbone Switching to via ATM (10 traffic streams) 10 Wandel & (each DominoLAN is connected to a single LAN) 10 s (each LAN is connected to a single switch port) Cabletron Systems Inc. SmartSwitch 9000 ATM OC-3 (Configured with a single PVC) Cabletron Systems Inc. SmartSwitch 9000 One Wandel & DominoLAN DA s (each LAN is connected to a single switch port) Network General Corp. Expert Sniffer Network Analyze Source: The Tolly Group, January 1998 Figure 10 measured, and recorded the input traffic. An 11 th DominoLAN DA-320 (analyzer version 2.2) was attached sequentially to each output LAN, where it measured and recorded throughput rates. An Expert Sniffer (version 4.52) decoded all output frames (see figure 10). 7RNHQ5LQJ6ZLWFKLQJ For the legacy switching tests, eight LANs served as the input to the switch under test and eight LANs served as the output. Attached to each input LAN, a DA-320 (analyzer version 2.2) generated, measured, and recorded the input traffic. An Expert Sniffer (version 4.52) decoded output traffic protocols (see figure 11). 7HVW0HWKRGRORJ\ In all test cases, The Tolly Group had three goals: to ascertain if the SmartSwitch 9000 is capable of successfully forwarding traffic between heterogeneous networks; to verify that the SmartSwitch 9000 properly translates traffic between heterogeneous networks; and to benchmark the forwarding capabilities and performance characteristics of the SmartSwitch With this in mind, The Tolly Group offered the appropriate amount of input traffic (originating on LANs) that would, in turn, fully utilize the output LAN(s). If the output or the target LAN was a Fast Ethernet (100 Mbit/s), for instance, The Tolly Group used seven LANs (7*16 Mbit/s = 112 Mbit/s) as the network input (Note: input traffic never exceeded the output LAN s capacity). Additionally, The Tolly Group chose to use IPX frames for testing. Normally, upper layer protocols are not important, since the SmartSwitch 9000 is a layer two switch. However, since the SmartSwitch 9000 translated IPX traffic, it had to successfully translate the source and destination network addresses found in the IPX portion of the frame, as well as the source and destination MAC addresses. Thus, IPX frames require the maximum amount of translation. For all tests conducted throughput as well as frame handling The Tolly Group began by generating traffic on all input streams simultaneously at bandwidth of target media and recorded any differences between offered load and received load. If no difference between the offered and received loads was observed, The Tolly Group incrementally adjusted the offered load until the system reached its maximum zero-loss throughput level. The Tolly Group considered the system to deliver zero-loss performance if the offered and received loads differed by less than 2%. If this did not occur, The Tolly Group reduced the offered load on all streams by the same rate until the offered and received streams differed by less than 2%. Tests covered frame sizes of 64-, 512-, 1,024-, 1,518-bytes, and, for tests of token ring and FDDI target LANs 3,972-bytes. (Note: 3,972- bytes is used rather than the more conventional 4,096-byte frame size because the former is the maximum frame size that the Wandel & test gear can generate.) 7HVW&DOFXODWLRQV Frame sizes on, Fast Ethernet, FDDI and Ethernet included four bytes of CRC. Theoretical maximum 16 Mbit/s frame rate for a frame of X bytes is defined by the following formula: (16,000,000 bits/s)/((8bits/byte)*x). Theoretical maximum fps rates for Fast Ethernet were calculated by adding 20 bytes to each frame size to account for the 0.96 microsecond interframe gap (equivalent to 12 bytes) and the frame s preamble (8 bytes). Thus, the theoretical maximum Fast Ethernet frame rate in fps for a frame of X bytes is defined by the following formula: (100,000,000 bits/s)/((8 bits/byte)*(x+20)). Theoretical maximum fps rates for FDDI were calculated by adding 11 bytes to each frame size to account for the frame s preamble (11 bytes). Thus, the theoretical maximum FDDI frame rate in fps for a frame of X bytes is defined by the following formula: (100,000,000 bits/s)/((8 bits/ byte)*(x+11)). Theoretical maximum fps rates for Ethernet were calculated by adding 20 bytes to each frame size to ac-

8 7KH7ROO\*URXS &DEOHWURQ6\VWHP 6PDUW6ZLWFK Legacy Switching to (Eight traffic streams) Four Wandel & Eight Wandel & (each DominoLAN is connected to a single ) Eight s (each LAN is connected to a single switch port) Cabletron Systems Inc. SmartSwitch 9000 Eight s (each LAN is connected to a single switch port) Network General Corp. Expert Sniffer Network Analyzer Source: The Tolly Group, January 1998 Figure 11 count for the 9.6 microsecond interframe gap (equivalent to 12 bytes) and the frame s preamble (8 bytes). Thus, the theoretical maximum Ethernet frame rate in fps for a frame of X bytes is defined by the following formula: (10,000,000 bits/s)/((8 bits/byte) *(X+20)). Theoretical maximum throughput in Mbit/s for the above topologies is defined by the following formula: ((topology theoretical maximum frame rate for X bytes frame in fps)*(x bytes/frame)*(8 bits/bytes))/ (1,000,000). The Tolly Group gratefully acknowledges the providers of test equipment used in this project. Vendor Product Web address Network General Corp. Expert Sniffer Network Analyzer Wandel & Inc. DA-320 DominoLAN Wandel & Inc. DA-330 Domino FDDI Wandel & Inc. DA-350 DominoFastEthernet 7he Tolly Group provides strategic consulting, independent testing, and industry analysis. It offers a full range of services designed to furnish both vendor and end-user communities with authoritative, unbiased information. Fortune 1,000 companies look to The Tolly Group for vendor-independent assessments of critical corporate technologies. Leading manufacturers of computer and communications products engage The Tolly Group to test both pre-production and production equipment. The Tolly Group is recognized worldwide for its expertise in assessing leading-edge technologies. By combining engineering-caliber test methodologies with informed interpretation, The Tolly Group consistently delivers 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. Tolly Group doc rev. lh/mc 4Feb98 $ERXW7KH7ROO\*URXS meaningful analyses of technology solutions. The Tolly Group has published more than 400 product evaluations, network design features and columns in the industry s most prestigious publications. Kevin Tolly is President and CEO of The Tolly Group. He is a leading industry analyst and is responsible for guiding the technology decisions of major vendor and end-user organizations. In his consulting work, Tolly has designed enterprise-wide networks for government agencies, banks, retailers, and manufacturers. For more information on The Tolly Group s services, visit our World Wide Web site at to info@tolly.com, call or , or fax