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Miscellaneous warnings: ---------------------------------------------------------------------------- == Line 90 has weird spacing: '...erfaces are g...' -- The exact meaning of the all-uppercase expression 'MAY NOT' is not defined in RFC 2119. If it is intended as a requirements expression, it should be rewritten using one of the combinations defined in RFC 2119; otherwise it should not be all-uppercase. == Using lowercase 'not' together with uppercase 'MUST', 'SHALL', 'SHOULD', or 'RECOMMENDED' is not an accepted usage according to RFC 2119. Please use uppercase 'NOT' together with RFC 2119 keywords (if that is what you mean). Found 'MUST not' in this paragraph: Any frame originating from the DUT/SUT (spanning tree, SNMP, RIP, ...) MUST not be counted as a received frame. Frames originating from the DUT/SUT MAY be counted as flooded frames or not counted at all. == Using lowercase 'not' together with uppercase 'MUST', 'SHALL', 'SHOULD', or 'RECOMMENDED' is not an accepted usage according to RFC 2119. Please use uppercase 'NOT' together with RFC 2119 keywords (if that is what you mean). Found 'MUST not' in this paragraph: Any frame originating from the DUT/SUT MUST not be counted as a received frame. Frames originating from the DUT/SUT MAY be counted as flooded frames or not counted at all. == Using lowercase 'not' together with uppercase 'MUST', 'SHALL', 'SHOULD', or 'RECOMMENDED' is not an accepted usage according to RFC 2119. Please use uppercase 'NOT' together with RFC 2119 keywords (if that is what you mean). Found 'MUST not' in this paragraph: Any frame originating from the DUT/SUT MUST not be counted as a received frame. Frames originating from the DUT/SUT MAY be counted as flooded frames or not counted at all. == Using lowercase 'not' together with uppercase 'MUST', 'SHALL', 'SHOULD', or 'RECOMMENDED' is not an accepted usage according to RFC 2119. Please use uppercase 'NOT' together with RFC 2119 keywords (if that is what you mean). Found 'MUST not' in this paragraph: Any frame originating from the DUT/SUT MUST not be counted as a received frame. Frames originating from the DUT/SUT MAY be counted as flooded frames or not counted at all. == Using lowercase 'not' together with uppercase 'MUST', 'SHALL', 'SHOULD', or 'RECOMMENDED' is not an accepted usage according to RFC 2119. Please use uppercase 'NOT' together with RFC 2119 keywords (if that is what you mean). 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Frames originating from the DUT/SUT MAY be counted as flooded frames or not counted at all. == The expression 'MAY NOT', while looking like RFC 2119 requirements text, is not defined in RFC 2119, and should not be used. Consider using 'MUST NOT' instead (if that is what you mean). Found 'MAY NOT' in this paragraph: All ports on the tester MUST transmit the exact number of test frames. The exact number is found by multiplying the Iload by the Trial Duration. All ports MAY NOT transmit the same number of frames if their Iload is not the same. An example would be the Partially meshed overloading test. -- The document seems to lack a disclaimer for pre-RFC5378 work, but may have content which was first submitted before 10 November 2008. If you have contacted all the original authors and they are all willing to grant the BCP78 rights to the IETF Trust, then this is fine, and you can ignore this comment. If not, you may need to add the pre-RFC5378 disclaimer. 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Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 1 Network Working Group R. Mandeville 2 Internet-Draft European Network Laboratories 3 Expiration Date: May 2000 J. Perser 4 Netcom Systems 5 November 1999 7 Benchmarking Methodology for LAN Switching Devices 8 10 Status of this Memo 12 This document is an Internet-Draft and is in full conformance with 13 all provisions of Section 10 of RFC2026. 15 Internet-Drafts are working documents of the Internet Engineering 16 Task Force (IETF), its areas, and its working groups. Note that 17 other groups may also distribute working documents as Internet- 18 Drafts. 20 Internet-Drafts are draft documents valid for a maximum of six months 21 and may be updated, replaced, or obsoleted by other documents at any 22 time. It is inappropriate to use Internet-Drafts as reference 23 material or to cite them other than as "work in progress." 25 The list of current Internet-Drafts can be accessed at 26 http://www.ietf.org/ietf/1id-abstracts.txt 28 The list of Internet-Draft Shadow Directories can be accessed at 29 http://www.ietf.org/shadow.html. 31 Table of Contents 33 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 34 2. Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 35 3. Test setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 36 4. Frame formats and sizes . . . . . . . . . . . . . . . . . . . . . 3 37 5. Benchmarking Tests . . . . . . . . . . . . . . . . . . . . . . . . 4 38 5.1 Fully meshed throughput, frame loss and forwarding rates . . 4 39 5.2 Partially meshed one-to-many/many-to-one . . . . . . . . . . 7 40 5.3 Partially meshed multiple devices . . . . . . . . . . . . . . 10 41 5.4 Partially meshed unidirectional traffic . . . . . . . . . . . 13 42 5.5 Congestion Control . . . . . . . . . . . . . . . . . . . . . 16 43 5.6 Forward Pressure and Maximum Forwarding Rate . . . . . . . . 19 44 5.7 Address caching capacity . . . . . . . . . . . . . . . . . . 21 45 5.8 Address learning rate . . . . . . . . . . . . . . . . . . . . 24 46 5.9 Errored frames filtering. . . . . . . . . . . . . . . . . . . 26 47 5.10 Broadcast frame Forwarding and Latency . . . . . . . . . . . 28 48 6. Security Considerations . . . . . . . . . . . . . . . . . . . . . 29 49 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 50 8. Authors' Address . . . . . . . . . . . . . . . . . . . . . . . . . 30 51 Appendix A: Formulas . . . . . . . . . . . . . . . . . . . . . . . 31 52 Appendix B: Generating Offered Load . . . . . . . . . . . . . . . 33 54 1. Introduction 56 This document is intended to provide methodology for the benchmarking 57 of local area network (LAN) switching devices. It extends the 58 methodology already defined for benchmarking network interconnecting 59 devices in RFC 2544 [3] to switching devices. 61 This RFC primarily deals with devices which switch frames at the 62 Medium Access Control (MAC) layer. It provides a methodology for 63 benchmarking switching devices, forwarding performance, congestion 64 control, latency, address handling and filtering. In addition to 65 defining the tests, this document also describes specific formats for 66 reporting the results of the tests. 68 A previous document, "Benchmarking Terminology for LAN Switching 69 Devices" [2], defined many of the terms that are used in this 70 document. The terminology document SHOULD be consulted before 71 attempting to make use of this document. 73 2. Requirements 75 The following RFCs SHOULD be consulted before attempting to make use 76 of this document: RFC 1242 [1], RFC 2285 [2], and RFC 2544 [3]. 78 For the sake of clarity and continuity, this RFC adopts the template 79 for benchmarking tests set out in Section 26 of RFC 2544. 81 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 82 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in 83 this document are to be interpreted as described in RFC 2119. 85 3. Test setup 87 This document extends the general test setup described in section 6 88 of RFC 2544 [3] to the benchmarking of LAN switching devices. 89 RFC 2544 [3] primarily describes non-meshed traffic where input and 90 output interfaces are grouped in mutually exclusive sending and 91 receiving pairs. In fully meshed traffic, each interface of a 92 DUT/SUT is set up to both receive and transmit frames to all the 93 other interfaces under test. 95 Prior to each test run, the DUT/SUT MUST learn the MAC addresses used 96 in the test and the address learning SHOULD be verified. Addresses 97 not learned will be forwarded as flooded frames and reduce the amount 98 of correctly forwarded frames. The rate at which address learning 99 frames are offered may have to be adjusted to be as low as 50 frames 100 per second or even less, to guarantee successful learning. The 101 DUT/SUT address aging time SHOULD be configured to be greater than 102 the period of the learning phase of the test plus the trial duration 103 plus any configuration time required by the testing device. 104 Addresses SHOULD NOT age out until the trial duration is completed. 105 More than one learning trial may be needed for the association of the 106 address to the port to occur. 108 If a DUT/SUT uses a hashing algorithm with address learning, the 109 DUT/SUT may not learn the necessary addresses to perform the tests. 110 The format of the MAC addresses MUST be adjustable so that the 111 address mapping may be re-arranged to ensure that the DUT/SUT learns 112 all the addresses. 114 4. Frame formats and sizes 116 The test frame format is defined in RFC 2544 section 8 [3] and MUST 117 contain a unique signature field located in the UDP DATA area of the 118 Test Frame (see Appendix C [3]). The purpose of the signature field 119 is filter out frames that are not part of the offered load. 121 The signature field MUST be unique enough to identify the frames not 122 originating from the DUT/SUT. The signature field SHOULD be located 123 after byte 56 (collision window [4] ) or at the end of the frame. 124 The length, contents and method of detection is not defined in this 125 memo. 127 The signature field MAY have a unique identifier per port. This 128 would filter out misforwarded frames. It is possible for a DUT/SUT 129 to strip off the MAC layer, send it through its switching matrix, 130 and transmit it out with the correct destination MAC address but the 131 wrong payload. 133 For frame sizes, refer to RFC 2544, section 9 [3]. 135 There are three possible frame formats for layer 2 Ethernet switches: 136 standard MAC Ethernet frames, standard MAC Ethernet frames with 137 vendor-specific tags added to them, and IEEE 802.3ac frames tagged to 138 accommodate 802.1p&Q. The two types of tagged frames may exceed the 139 standard maximum length frame of 1518 bytes, and may not be accepted 140 by the interface controllers of some DUT/SUTs. It is recommended to 141 check the compatibility of the DUT/SUT with tagged frames before 142 testing. 144 Devices switching tagged frames of over 1518 bytes will have a 145 different maximum forwarding rate than untagged frames. 147 5. Benchmarking Tests 149 The following tests offer objectives, procedures, and reporting 150 formats for benchmarking LAN switching devices. 152 5.1 Fully meshed throughput, frame loss and forwarding rates 154 5.1.1 Objective 156 To determine the throughput, frame loss and forwarding rates of 157 DUT/SUTs offered fully meshed traffic as defined in RFC 2285 [2]. 159 5.1.2 Setup Parameters 161 When offering full meshed traffic, the following parameters MUST be 162 defined. Each parameter is configured with the following 163 considerations. 165 Frame Size - Recommended frame sizes are 64, 128, 256, 512, 1024, 166 1280 and 1518 bytes, per RFC 2544 section 9 [3]. The four CRC 167 bytes are included in the frame size specified. 169 Interframe Gap (IFG) - The IFG between frames inside a burst 170 MUST be at the minimum specified by the standard (9.6 us for 171 10Mbps Ethernet, 960 ns for 100Mbps Ethernet, and 96 ns for 172 1 Gbps Ethernet) of the medium being tested. 174 Duplex mode - Half duplex or full duplex. 176 ILoad - Intended Load per port is expressed in a percentage of the 177 medium's maximum theoretical load, regardless of traffic 178 orientation or duplex mode. Certain test configurations will 179 theoretically over-subscribe the DUT/SUT. 181 In half duplex, an ILoad over 50% will over-subscribe the DUT/SUT. 183 Burst Size - The burst size defines the number of frames sent 184 back-to-back at the minimum legal IFG [4] before pausing 185 transmission to receive frames. Burst sizes SHOULD vary between 1 186 and 930 frames. A burst size of 1 will simulate constant load 187 [1]. 189 Addresses per port - Represents the number of addresses which 190 are being tested for each port. Number of addresses SHOULD be a 191 binary exponential (i.e. 1, 2, 4, 8, 16, 32, 64, 128, 256, ...). 192 Recommended value is 1. 194 Trial Duration - The recommended Trial Duration is 30 seconds. 195 Trial duration SHOULD be adjustable between 1 and 300 seconds. 197 5.1.3 Procedure 199 All ports on the tester MUST transmit test frames either in a Frame 200 Based or Time Based mode (Appendix B). All ports SHOULD start 201 transmitting their frames within 1% of the trial duration. For a 202 trial duration of 30 seconds, all ports SHOULD have started 203 transmitting frames within 300 milliseconds of each other. 205 Each port in the test MUST send test frames to all other ports in a 206 round robin type fashion. The sequence of addresses MUST NOT change 207 when backpressure is applied. The following table shows how each 208 port in a test MUST transmit test frames to all other ports in the 209 test. In this example, there are six ports with 1 address per port: 211 Source Port Destination Ports (in order of transmission) 213 Port #1 2 3 4 5 6 2... 214 Port #2 3 4 5 6 1 3... 215 Port #3 4 5 6 1 2 4... 216 Port #4 5 6 1 2 3 5... 217 Port #5 6 1 2 3 4 6... 218 Port #6 1 2 3 4 5 1... 220 As shown in the table, there is an equal distribution of destination 221 addresses for each transmit opportunity. This keeps the test balanced 222 so that one destination port is not overloaded by the test algorithm 223 and all ports are equally and fully loaded throughout the test. Not 224 following this algorithm exactly will produce inconsistent results. 226 For tests using multiple addresses per port, the actual port 227 destinations are the same as described above and the actual 228 source/destination address pairs SHOULD be chosen randomly to 229 exercise the DUT/SUT's ability to perform address lookups. 231 For every address, learning frames MUST be sent to the DUT/SUT to 232 allow the DUT/SUT update its address tables properly. 234 5.1.4 Measurements 236 Each port should receive the same number of test frames that it 237 transmitted. Each receiving port MUST categorize, then count the 238 frames into one of two groups: 240 1.) Received Frames: received frames MUST have the correct 241 destination MAC address and SHOULD match a signature field. 243 2.) Flood count [2]. 245 Any frame originating from the DUT/SUT (spanning tree, SNMP, RIP, 246 ...) MUST not be counted as a received frame. Frames originating 247 from the DUT/SUT MAY be counted as flooded frames or not counted at 248 all. 250 Frame loss rate of the DUT/SUT SHOULD be reported as defined in 251 section 26.3 [3] with the following notes: Frame loss rate SHOULD be 252 measured at the end of the trail duration. The term "rate", for this 253 measurement only, does not imply the units in the fashion of "per 254 second." 256 5.1.4.1 Throughput 258 Throughput measurement is defined in section 26.1 [3]. A search 259 algorithm is employed to find the maximum Oload [2] with a zero Frame 260 loss rate [1]. The algorithm MUST adjust Iload to find the 261 throughput. 263 5.1.4.2 Forwarding Rate 265 Forwarding rate (FR) of the DUT/SUT SHOULD be reported as the number 266 of test frames per second that the device is observed to successfully 267 forward to the correct destination interface in response to a 268 specified Oload. The Oload MUST also be cited. 270 Forwarding rate at maximum offered load (FRMOL) MUST be reported 271 as the number of test frames per second that a device can 272 successfully transmit to the correct destination interface in 273 response to the MOL as defined in section 3.6 [2]. The MOL MUST also 274 be cited. 276 Maximum forwarding rate (MFR) MUST be reported as the highest 277 forwarding rate of a DUT/SUT taken from an iterative set of 278 forwarding rate measurements. The iterative set of forwarding rate 279 measurements are made by adjusting Iload. The Oload applied to the 280 device MUST also be cited. 282 5.1.5 Reporting format 284 The results for these tests SHOULD be reported in the form of a 285 graph. The x coordinate SHOULD be the frame size, the y coordinate 286 SHOULD be the test results. There SHOULD be at least two lines on 287 the graph, one plotting the theoretical and one plotting the test 288 results. 290 To measure the DUT/SUT's ability to switch traffic while performing 291 many different address lookups, the number of addresses per port 292 MAY be increased in a series of tests. 294 5.2 Partially meshed one-to-many/many-to-one 296 5.2.1 Objective 298 To determine the throughput when transmitting from/to multiple ports 299 and to/from one port. As with the fully meshed throughput test, this 300 test is a measure of the capability of the DUT to switch frames 301 without frame loss. Results of this test can be used to determine 302 the ability of the DUT to utilize an Ethernet port when switching 303 traffic from multiple Ethernet ports. 305 5.2.2 Setup Parameters 307 When offering bursty meshed traffic, the following parameters MUST 308 be defined. Each parameter is configured with the following 309 considerations. 311 Frame Size - Recommended frame sizes are 64, 128, 256, 512, 1024, 312 1280 and 1518 bytes, per RFC 2544 section 9 [3]. The four CRC 313 bytes are included in the frame size specified. 315 Traffic Direction - Traffic can be generated in one direction, the 316 reverse direction, or both directions. 318 Interframe Gap (IFG) - The IFG between frames inside a burst 319 MUST be at the minimum specified by the standard (9.6 us for 320 10Mbps Ethernet, 960 ns for 100Mbps Ethernet, and 96 ns for 321 1 Gbps Ethernet) of the medium being tested. 323 Duplex mode - Half duplex or full duplex. 325 ILoad - Intended Load per port is expressed in a percentage of the 326 medium's maximum theoretical load, regardless of traffic 327 orientation or duplex mode. Certain test configurations will 328 theoretically over-subscribe the DUT/SUT. 330 In half duplex bidirectional traffic, an ILoad over 50% will over- 331 subscribe the DUT/SUT. 333 Burst Size - The burst size defines the number of frames sent 334 back-to-back at the minimum legal IFG [4] before pausing 335 transmission to receive frames. Burst sizes SHOULD vary between 1 336 and 930 frames. A burst size of 1 will simulate constant load 337 [1]. 339 Addresses per port - Represents the number of addresses which 340 are being tested for each port. Number of addresses SHOULD be a 341 binary exponential (i.e. 1, 2, 4, 8, 16, 32, 64, 128, 256, ...). 342 Recommended value is 1. 344 Trial Duration - The recommended Trial Duration is 30 seconds. 345 Trial duration SHOULD be adjustable between 1 and 300 seconds. 347 5.2.3 Procedure 349 All ports on the tester MUST transmit test frames either in a Frame 350 Based or Time Based mode (Appendix B). Depending upon traffic 351 direction, some or all of the ports will be transmitting. All ports 352 SHOULD start transmitting their frames within 1% of the trial 353 duration. For a trial duration of 30 seconds, all ports SHOULD have 354 started transmitting frames within 300 milliseconds of each other. 356 Test frames transmitted from the Many Ports MUST be destined to the 357 One port. Test frames transmitted from the One Port MUST be destined 358 to the Many ports in a round robin type fashion. See section 5.1.3 359 for a description of the round robin fashion. 361 For tests using multiple addresses per port, the actual port 362 destinations are the same as described above and the actual 363 source/destination address pairs SHOULD be chosen randomly to 364 exercise the DUT/SUT's ability to perform address lookups. 366 +----------+ 367 | | 368 | Many | <-------- 369 | | \ 370 +----------+ \ 371 \ 372 +----------+ \ +-------------+ 373 | | ------------> | | 374 | Many | <-----------------------> | One | 375 | | ------------> | | 376 +----------+ / +-------------+ 377 / 378 +----------+ / 379 | | / 380 | Many | <------- 381 | | 382 +----------+ 384 For every address, the testing device MUST send learning frames to 385 allow the DUT/SUT to update its address tables properly. 387 5.2.4 Measurements 389 Each receiving port MUST categorize, then count the frames into one 390 of two groups: 392 1.) Received Frames: received frames MUST have the correct 393 destination MAC address and SHOULD match a signature field. 395 2.) Flood count [2]. 397 Any frame originating from the DUT/SUT MUST not be counted as a 398 received frame. Frames originating from the DUT/SUT MAY be counted 399 as flooded frames or not counted at all. 401 Forwarding rate (FR) of the DUT/SUT SHOULD be reported as the number 402 of test frames per second that the device is observed to successfully 403 transmit to the correct destination interface in response to a 404 specified Oload. The Oload MUST also be cited. 406 Forwarding rate at maximum offered load (FRMOL) MUST be reported 407 as the number of test frames per second that a device can 408 successfully transmit to the correct destination interface in 409 response to the MOL as defined in section 3.6 [2]. The MOL MUST also 410 be cited. 412 Maximum forwarding rate (MFR) MUST be reported as the highest 413 forwarding rate of a DUT/SUT taken from an iterative set of 414 forwarding rate measurements. The iterative set of forwarding rate 415 measurements are made by adjusting Iload. The Oload applied to the 416 device MUST also be cited. 418 5.2.5 Reporting Format 420 The results for these tests SHOULD be reported in the form of a 421 graph. The x coordinate SHOULD be the frame size, the y coordinate 422 SHOULD be the test results. There SHOULD be at least two lines on 423 the graph, one plotting the theoretical and one plotting the test 424 results. 426 To measure the DUT/SUT's ability to switch traffic while performing 427 many different address lookups, the number of addresses per port 428 MAY be increased in a series of tests. 430 5.3 Partially meshed multiple devices 432 5.3.1 Objective 434 To determine the throughput, frame loss and forwarding rates of two 435 switching devices equipped with multiple ports and one high speed 436 backbone uplink (Gigabit Ethernet, ATM, SONET). 438 5.3.2 Setup Parameters 440 When offering bursty partially meshed traffic, the following 441 parameters MUST be defined. Each variable is configured with the 442 following considerations. 444 Frame Size - Recommended frame sizes are 64, 128, 256, 512, 1024, 445 1280 and 1518 bytes, per RFC 2544 section 9 [3]. The four CRC 446 bytes are included in the frame size specified. 448 Interframe Gap (IFG) - The IFG between frames inside a burst 449 MUST be at the minimum specified by the standard (9.6 us for 450 10Mbps Ethernet, 960 ns for 100Mbps Ethernet, and 96 ns for 451 1 Gbps Ethernet) of the medium being tested. 453 Duplex mode - Half duplex or full duplex. 455 ILoad - Intended Load per port is expressed in a percentage of the 456 medium's maximum theoretical load, regardless of traffic 457 orientation or duplex mode. Certain test configurations will 458 theoretically over-subscribe the DUT/SUT. 460 In half duplex, an ILoad over 50% will over-subscribe the DUT/SUT. 462 Burst Size - The burst size defines the number of frames sent 463 back-to-back at the minimum legal IFG [4] before pausing 464 transmission to receive frames. Burst sizes SHOULD vary between 1 465 and 930 frames. A burst size of 1 will simulate constant load 466 [1]. 468 Addresses per port - Represents the number of addresses which 469 are being tested for each port. Number of addresses SHOULD be a 470 binary exponential (i.e. 1, 2, 4, 8, 16, 32, 64, 128, 256, ...). 471 Recommended value is 1. 473 Trial Duration - The recommended Trial Duration is 30 seconds. 474 Trial duration SHOULD be adjustable between 1 and 300 seconds. 476 Local Traffic - A Boolean value of ON or OFF. The frame 477 sequence 478 algorithm MAY be altered to remove local traffic. With local 479 traffic ON, the algorithm is exactly the same as a fully meshed 480 throughput. With local traffic OFF, the port sends frames to all 481 other ports on the other side of the backbone uplink in a round 482 robin type fashion. 484 5.3.3 Procedure 486 All ports on the tester MUST transmit test frames either in a Frame 487 Based or Time Based mode (Appendix B). All ports SHOULD start 488 transmitting their frames within 1% of the trial duration. For a 489 trial duration of 30 seconds, all ports SHOULD have started 490 transmitting frames with 300 milliseconds of each other. 492 Each port in the test MUST send test frames to all other ports in a 493 round robin type fashion as defined in section 5.1.3. Local traffic 494 MAY be removed from the round robin list in order to send the entire 495 load across the backbone uplink. 497 For tests using multiple addresses per port, the actual port 498 destinations are the same as described above and the actual 499 source/destination address pairs SHOULD be chosen randomly to 500 exercise the DUT/SUT's ability to perform address lookups. 502 For every address, the testing device MUST send learning frames to 503 allow the DUT/SUT to update its address tables properly. 505 To measure the DUT/SUT's ability to switch traffic while performing 506 many different address lookups, the number of addresses per port 507 MAY be increased in a series of tests. 509 5.3.4 Measurements 511 Each receiving port MUST categorize, then count the frames into one 512 of two groups: 514 1.) Received frames MUST have the correct destination MAC address 515 and SHOULD match a signature field. 517 2.) Flood count [2]. 519 Any frame originating from the DUT/SUT MUST not be counted as a 520 received frame. Frames originating from the DUT/SUT MAY be counted 521 as flooded frames or not counted at all. 523 Frame loss rate of the DUT/SUT SHOULD be reported as defined in 524 section 26.3 [3] with the following notes: Frame loss rate SHOULD be 525 measured at the end of the trial duration. The term "rate", for this 526 measurement only, does not imply the units in the fashion of "per 527 second." 529 5.3.4.1 Throughput 531 Throughput measurement is defined in section 26.1 [3]. A search 532 algorithm is employed to find the maximum Oload [2] with a zero Frame 533 loss rate [1]. The algorithm MUST adjust Iload to find the 534 throughput. 536 5.3.4.2 Forwarding rate 538 Forwarding rate (FR) of the DUT/SUT SHOULD be reported as the number 539 of test frames per second that the device is observed to successfully 540 forward to the correct destination interface in response to a 541 specified Oload. The Oload MUST also be cited. 543 Forwarding rate at maximum offered load (FRMOL) MUST be reported 544 as the number of test frames per second that a device can 545 successfully transmit to the correct destination interface in 546 response to the MOL as defined in section 3.6 [2]. The MOL MUST also 547 be cited. 549 Maximum forwarding rate (MFR) MUST be reported as the highest 550 forwarding rate of a DUT/SUT taken from an iterative set of 551 forwarding rate measurements. The iterative set of forwarding rate 552 measurements are made by adjusting Iload. The Oload applied to the 553 device MUST also be cited. 555 5.3.5 Reporting format 557 The results for these tests SHOULD be reported in the form of a 558 graph. The x coordinate SHOULD be the frame size, the y coordinate 559 SHOULD be the test results. There SHOULD be at least two lines on 560 the graph, one plotting the theoretical and one plotting the test 561 results. 563 To measure the DUT/SUT's ability to switch traffic while performing 564 many different address lookups, the number of addresses per port 565 MAY be increased in a series of tests. 567 5.4 Partially meshed unidirectional traffic 569 5.4.1 Objective 571 To determine the throughput of the DUT/SUT when presented multiple 572 streams of unidirectional traffic with half of the ports on the 573 DUT/SUT are transmitting frames destined to the other half of the 574 ports. 576 5.4.2 Setup Parameters 578 The following parameters MUST be defined. Each variable is 579 configured with the following considerations. 581 Frame Size - Recommended frame sizes are 64, 128, 256, 512, 1024, 582 1280 and 1518 bytes, per RFC 2544 section 9 [3]. The four CRC 583 bytes are included in the frame size specified. 585 Interframe Gap (IFG) - The IFG between frames inside a burst 586 MUST be at the minimum specified by the standard (9.6 us for 587 10Mbps Ethernet, 960 ns for 100Mbps Ethernet, and 96 ns for 588 1 Gbps Ethernet) of the medium being tested. 590 Duplex mode - Half duplex or full duplex. 592 ILoad - Intended Load per port is expressed in a percentage of the 593 medium's maximum theoretical load, regardless of traffic 594 orientation or duplex mode. Certain test configurations will 595 theoretically over-subscribe the DUT/SUT. 597 ILoad will not over-subscribe the DUT/SUT in this test. 599 Burst Size - The burst size defines the number of frames sent 600 back-to-back at the minimum legal IFG [4] before pausing 601 transmission to receive frames. Burst sizes SHOULD vary between 1 602 and 930 frames. A burst size of 1 will simulate constant load 603 [1]. 605 Addresses per port - Represents the number of addresses which 606 are being tested for each port. Number of addresses SHOULD be a 607 binary exponential (i.e. 1, 2, 4, 8, 16, 32, 64, 128, 256, ...). 608 Recommended value is 1. 610 Trial Duration - The recommended Trial Duration is 30 seconds. 611 Trial duration SHOULD be adjustable between 1 and 300 seconds. 613 5.4.3 Procedure 615 Ports do not send and receive test frames simultaneously. As a 616 consequence, there should be no collisions unless the DUT is 617 misforwarding frames, generating flooded or Spanning-Tree frames or 618 is enabling some flow control mechanism. Ports used for this test 619 are either transmitting or receiving, but not both. Those ports which 620 are transmitting send test frames destined to addresses corresponding 621 to each of the ports receiving. This creates a unidirectional mesh 622 of traffic. 624 All ports on the tester MUST transmit test frames either in a Frame 625 Based or Time Based mode (Appendix B). All ports SHOULD start 626 transmitting their frames within 1% of the trial duration. For a 627 trial duration of 30 seconds, all ports SHOULD have started 628 transmitting frames with 300 milliseconds of each other. 630 Each transmitting port in the test MUST send frames to all receiving 631 ports in a round robin type fashion. The sequence of addresses MUST 632 NOT change when backpressure is applied. The following table shows 633 how each port in a test MUST transmit test frames to all other ports 634 in the test. In this 8 port example, port 1 through 4 are 635 transmitting and ports 5 through 8 are receiving; each with 1 address 636 per port: 638 Source Port, then Destination Ports (in order of transmission) 640 Port #1 5 6 7 8 5 6... 641 Port #2 6 7 8 5 6 7... 642 Port #3 7 8 5 6 7 8... 643 Port #4 8 5 6 7 8 5... 645 As shown in the table, there is an equal distribution of destination 646 addresses for each transmit opportunity. This keeps the test balanced 647 so that one destination port is not overloaded by the test algorithm 648 and all receiving ports are equally and fully loaded throughout the 649 test. Not following this algorithm exactly will product inconsistent 650 results. 652 For tests using multiple addresses per port, the actual port 653 destinations are the same as described above and the actual 654 source/destination address pairs SHOULD be chosen randomly to 655 exercise the DUT/SUT's ability to perform address lookups. 657 For every address, the testing device MUST send learning frames to 658 allow the DUT/SUT to load its address tables properly. The address 659 table's aging time SHOULD be set sufficiently longer than the 660 learning time and trial duration time combined. If the address table 661 ages out during the test, the results will show a lower performing 662 DUT/SUT. 664 To measure the DUT/SUT's ability to switch traffic while performing 665 many different address lookups, the number of addresses per port 666 MAY be increased in a series of tests. 668 5.4.4 Measurements 670 Each receiving port MUST categorize, then count the frames into one 671 of two groups: 673 1.) Received Frames: received frames MUST have the correct 674 destination MAC address and SHOULD match a signature field. 676 2.) Flood count [2]. 678 Any frame originating from the DUT/SUT MUST not be counted as a 679 received frame. Frames originating from the DUT/SUT MAY be counted 680 as flooded frames or not counted at all. 682 Frame loss rate of the DUT/SUT SHOULD be reported as defined in 683 section 26.3 [3] with the following notes: Frame loss rate SHOULD be 684 measured at the end of the trial duration. The term "rate", for this 685 measurement only, does not imply the units in the fashion of "per 686 second." 688 5.4.4.1 Throughput 690 Throughput measurement is defined in section 26.1 [3]. A search 691 algorithm is employed to find the maximum Oload [2] with a zero Frame 692 loss rate [1]. The algorithm MUST adjust Iload to find the 693 throughput. 695 5.4.4.2 Forwarding rate 697 Forwarding rate (FR) of the DUT/SUT SHOULD be reported as the number 698 of test frames per second that the device is observed to successfully 699 forward to the correct destination interface in response to a 700 specified Oload. The Oload MUST also be cited. 702 Forwarding rate at maximum offered load (FRMOL) MUST be reported 703 as the number of test frames per second that a device can 704 successfully transmit to the correct destination interface in 705 response to the MOL as defined in section 3.6 [2]. The MOL MUST also 706 be cited. 708 Maximum forwarding rate (MFR) MUST be reported as the highest 709 forwarding rate of a DUT/SUT taken from an iterative set of 710 forwarding rate measurements. The iterative set of forwarding rate 711 measurements are made by adjusting Iload. The Oload applied to the 712 device MUST also be cited. 714 5.4.5 Reporting format 716 The results for these tests SHOULD be reported in the form of a 717 graph. The x coordinate SHOULD be the frame size, the y coordinate 718 SHOULD be the test results. There SHOULD be at least two lines on 719 the graph, one plotting the theoretical and one plotting the test 720 results. 722 To measure the DUT/SUT's ability to switch traffic while performing 723 many different address lookups, the number of addresses per port 724 MAY be increased in a series of tests. 726 5.5 Congestion Control 728 5.5.1 Objective 730 To determine how a DUT handles congestion. Does the device implement 731 back pressure (congestion control) and does congestion on one port 732 affect an uncongested port. This procedure determines if Head of 733 Line Blocking and/or Backpressure are present. 735 5.5.2 Setup Parameters 737 The following parameters MUST be defined. Each variable is 738 configured with the following considerations. 740 Frame Size - Recommended frame sizes are 64, 128, 256, 512, 1024, 741 1280 and 1518 bytes, per RFC 2544 section 9 [3]. The four CRC 742 bytes are included in the frame size specified. 744 Interframe Gap (IFG) - The IFG between frames inside a burst 745 MUST be at the minimum specified by the standard (9.6 us for 746 10Mbps Ethernet, 960 ns for 100Mbps Ethernet, and 96 ns for 747 1 Gbps Ethernet) of the medium being tested. 749 Duplex mode - Half duplex or full duplex. 751 Addresses per port - Represents the number of addresses which 752 are being tested for each port. Number of addresses SHOULD be a 753 binary exponential (i.e. 1, 2, 4, 8, 16, 32, 64, 128, 256, ...). 754 Recommended value is 1. 756 Trial Duration - The recommended Trial Duration is 30 seconds. 757 Trial duration SHOULD be adjustable between 1 and 300 seconds. 759 5.5.3 Procedure 761 This test MUST consist of a multiple of four ports. Four ports are 762 REQUIRED and MAY be expanded to fully utilize the DUT/SUT in 763 increments of four. Each group of four will contain a test block 764 with two of the ports as source transmitters and two of the ports as 765 receivers. The diagram below depicts the flow of traffic between the 766 switch ports: 768 +----------+ 50 % MOL +-------------+ 769 | | ------------------------> | | 770 | | 50 % MOL | uncongested | 771 | | --------- | | 772 +----------+ \ +-------------+ 773 \ 774 \ 775 \ 776 +----------+ \ +-------------+ 777 | | ---------> | | 778 | | 100 % MOL | congested | 779 | | ------------------------> | | 780 +----------+ +-------------+ 782 Both source transmitters MUST transmit the exact number of test 783 frames. The first source MUST transmit test frames at the MOL with 784 the destination address of the two receive ports in an alternating 785 order. The first test frame to the uncongested receive port, second 786 test frame to the congested receive port, then repeat. The second 787 source transmitter MUST transmit test frames at the MOL only to the 788 congested receive port. 790 Both receive ports SHOULD distinguish between test frames originating 791 from the source ports and frames originating from the DUT/SUT. Only 792 test frames from the source ports SHOULD be counted. 794 The uncongested receive port should be receiving at a rate of half 795 the MOL. The number of test frames received on the uncongested port 796 SHOULD be 50% of the test frames transmitted by the first source 797 transmitter. The congested receive port should be receiving at the 798 MOL. The number of test frames received on the congested port should 799 be between 100% and 150% of the test frames transmitted by one source 800 transmitter. 802 Test frames destined to uncongested ports in a switch device should 803 not be dropped due to other ports being congested, even if the source 804 is sending to both the congested and uncongested ports. 806 5.5.4 Measurements 808 Any frame received which does not have the correct destination 809 address MUST not be counted as a received frame and SHOULD be counted 810 as part of a flood count. 812 Any frame originating from the DUT/SUT MUST not be counted as a 813 received frame. Frames originating from the DUT/SUT MAY be counted 814 as flooded frames or not counted at all. 816 Frame loss rate of the DUT/SUT's congested and uncongested ports MUST 817 be reported as defined in section 26.3 [3] with the following notes: 818 Frame loss rate SHOULD be measured at the end of the trial duration. 819 The term "rate", for this measurement only, does not imply the units 820 in the fashion of "per second." 822 Offered Load to the DUT/SUT MUST be reported as the number of test 823 frames per second that the DUT/SUT observed to accept. This may be 824 different that the MOL. 826 Forwarding rate (FR) of the DUT/SUT's congested and uncongested ports 827 MUST be reported as the number of test frames per second that the 828 device is observed to successfully transmit to the correct 829 destination interface in response to a specified offered load. The 830 offered load MUST also be cited. 832 5.5.5 Reporting format 834 This test MUST report the frame lost rate at the uncongested port, 835 the maximum forwarding rate (at 50% offered load) at the uncongested 836 port, and the frame lost rate at the congested port. This test MAY 837 report the frame counts transmitted and frame counts received by the 838 DUT/SUT. 840 5.5.5.1 HOLB 842 If there is frame loss at the uncongested port, "Head of Line" 843 blocking is present. The DUT cannot forward the amount of traffic to 844 the congested port and as a result it is also losing frames destined 845 to the uncongested port. 847 5.5.5.2 Back Pressure 849 If there is no frame loss on the congested port, then backpressure 850 is present. It should be noted that this test expects the overall 851 load to the congested port to be greater than 100%. Therefore if the 852 load is greater than 100% and no frame loss is detected, then the DUT 853 must be implementing a flow control mechanism. The type of flow 854 control mechanism used is beyond the scope of this memo. 856 It should be noted that some DUTs may not be able to handle the 100% 857 load presented at the input port. In this case, there may be frame 858 loss reported at the uncongested port which is due to the load at the 859 input port rather than the congested port's load. 861 If the uncongested frame loss is reported as zero, but the maximum 862 forwarding rate is less than 7440 (for 10Mbps Ethernet), then this 863 may be an indication of congestion control being enforced by the DUT. 864 In this case, the congestion control is affecting the throughput of 865 the uncongested port. 867 If no congestion control is detected, the expected percentage frame 868 loss for the congested port is 33% at 150% overload. It is receiving 869 100% load from 1 port, and 50% from another, and can only get 100% 870 possible throughput, therefore having a frame loss rate of 33% 871 (150%-50%/150%). 873 5.6 Forward Pressure and Maximum Forwarding Rate 875 5.6.1 Objective 877 The Forward Pressure test overloads a DUT/SUT port and measures the 878 output for forward pressure [2]. If the DUT/SUT transmits frames 879 with an interframe gap less than 96 bits (section 4.2.3.2.2 [4]), 880 then forward pressure is detected. 882 The objective of the Maximum Forwarding Rate test is to measure the 883 peak value of the Forwarding Rate when the Offered Load is varied 884 between the throughput [1] and the Maximum Offered Load [2]. 886 5.6.2 Setup Parameters 888 The following parameters MUST be defined. Each variable is 889 configured with the following considerations. 891 Frame Size - Recommended frame sizes are 64, 128, 256, 512, 1024, 892 1280 and 1518 bytes, per RFC 2544 section 9 [3]. The four CRC 893 bytes are included in the frame size specified. 895 Duplex mode - Half duplex or full duplex. 897 Trial Duration - The recommended Trial Duration is 30 seconds. 898 Trial duration SHOULD be adjustable between 1 and 300 seconds. 900 Step Size - The minimum incremental resolution that the Iload 901 will 902 be incremented in frames per second. The smaller the step size, 903 the more accurate the measurement and the more iterations 904 required. As the Iload approaches the MOL, the minimum step size 905 will increase because of gap resolution on the testing device. 907 5.6.3 Procedure 909 5.6.3.1 Maximum forwarding rate 911 If the Throughput [1] and the MOL [2] are the same, then MFR [2] 912 is equal to the MOL [2]. 914 This test MUST at a minimum be performed in a two-port configuration 915 as described below. Learning frames MUST be sent to allow the 916 DUT/SUT to update its address tables properly. 918 Test frames are transmitted to the first port (port 1) of the DUT/SUT 919 at the Iload. The FR [2] on the second port (port 2) of the DUT/SUT 920 is measured. The Iload is incremented for each Step Size to find the 921 MFR. The algorithm for the test is as follows: 923 CONSTANT 924 MOL = ... frames/sec; {Maximum Offered Load} 925 VARIABLE 926 MFR := 0 frames/sec; {Maximum Forwarding Rate} 927 ILOAD := starting throughput in frames/sec; {offered load} 928 STEP := ... frames/sec; {Step Size} 929 BEGIN 930 ILOAD := ILOAD - STEP; 931 DO 932 BEGIN 933 ILOAD := ILOAD + STEP 934 IF (ILOAD > MOL) THEN 935 BEGIN 936 ILOAD := MOL 937 END 938 AddressLearning; {Port 2 broadcasts with its source address} 939 Transmit(ILOAD); {Port 1 sends frames to Port 2 at Offered load} 940 IF (Port 2 Forwarding Rate > MFR) THEN 941 BEGIN 942 MFR := Port 2 Forwarding Rate; {A higher value than before} 943 END 944 END 945 WHILE (ILOAD < MOL); {ILOAD has reached the MOL value} 946 DONE 948 5.6.3.2 Minimum Interframe Gap 950 The Minimum Interframe gap test SHOULD, at a minimum, be performed in 951 a two-port configuration as described below. Learning frames MUST be 952 sent to allow the DUT/SUT to update its address tables properly. 954 Test frames SHOULD be transmitted to the first port (port 1) of the 955 DUT/SUT with an interframe gap of 88 bits. This will apply forward 956 pressure to the DUT/SUT and overload it at a rate of one byte per 957 frame. The test frames MUST be constructed with a source address of 958 port 1 and a destination address of port 2. 960 The FR on the second port (port 2) of the DUT/SUT is measured. The 961 measured Forwarding Rate should not exceed the medium's maximum 962 theoretical utilization (MOL). 964 5.6.4 Measurements 966 Port 2 MUST categorize, then count the frames into one of two groups: 968 1.) Received Frames: received frames MUST have the correct 969 destination MAC address and SHOULD match a signature field. 971 2.) Flood count [2]. 973 Any frame originating from the DUT/SUT MUST not be counted as a 974 received frame. Frames originating from the DUT/SUT MAY be counted 975 as flooded frames or not counted at all. 977 5.6.5 Reporting format 979 MFR MUST be reported as the highest forwarding rate of a DUT/SUT 980 taken from an iterative set of forwarding rate measurements. The 981 Iload applied to the device MUST also be cited. 983 Forwarding rate (FR) of the DUT/SUT SHOULD be reported as the number 984 of frames per second that the device is observed to successfully 985 transmit to the correct destination interface in response to a 986 specified Oload. The Iload MUST be cited and the Oload MAY be 987 recorded. 989 If the FR exceeds the MOL during the Minimum Interframe gap test, 990 this MUST be highlighted with the expression "Forward Pressure 991 detected". 993 5.7 Address Caching Capacity 995 5.7.1 Objective 997 To determine the address caching capacity of a LAN switching device 998 as defined in RFC 2285, section 3.8.1 [2]. 1000 5.7.2 Setup Parameters 1002 The following parameters MUST be defined. Each variable is 1003 configured with the following considerations. 1005 Age Time - The maximum time that a DUT/SUT will keep a learned 1006 address in its forwarding table. 1008 Addresses Learning Rate - The rate at which new addresses are 1009 offered to the DUT/SUT to be learned. The rate at which address 1010 learning frames are offered may have to be adjusted to be as low as 1011 50 frames per second or even less, to guarantee successful 1012 learning. 1014 Initial Addresses - The initial number of addresses to start the 1015 test with. The number MUST be between 1 and the maximum number 1016 supported by the implementation. 1018 5.7.3 Procedure 1020 The aging time of the DUT/SUT MUST be known. The aging time MUST be 1021 longer than the time necessary to produce frames at the specified 1022 rate. If a low frame rate is used for the test, then it may be 1023 possible that sending a large amount of frames may actually take 1024 longer than the aging time. 1026 This test MUST at a minimum be performed in a three-port 1027 configuration described below. The test MAY be expanded to fully 1028 utilized the DUT/SUT in increments of two or three ports. An 1029 increment of two would include an additional Learning port and Test 1030 port. An increment of three would include an additional Learning 1031 port, Test port, and Monitoring port. 1033 The Learning port (Lport) transmits learning frames to the DUT/SUT 1034 with varying source addresses and a fixed destination address 1035 corresponding to the address of the device connected to the Test port 1036 (Tport) of the DUT/SUT. By receiving frames with varying 1037 source addresses, the DUT/SUT should learn these new addresses. The 1038 source addresses MAY be in sequential order. 1040 The Test port (Tport) of the DUT/SUT acts as the receiving port for 1041 the learning frames. Test frames will be transmitted back to the 1042 addresses learned on the Learning port. The algorithm for this is 1043 explained below. 1045 The Monitoring port (Mport) on the DUT/SUT acts as a monitoring port 1046 to listen for flooded or mis-forwarded frames. If the test spans 1047 multiple broadcast domains (VLANs), each broadcast domain REQUIRES a 1048 Monitoring port. 1050 It is highly recommended that SNMP, Spanning Tree, and any other 1051 frames originating from the DUT/SUT be disabled when running this 1052 test. If such protocols cannot be turned off, the flood count MUST 1053 be modified only to count test frame originating from Lport and MUST 1054 NOT count frames originating from the DUT/SUT. 1056 The algorithm for the test is as follows: 1058 CONSTANT 1059 AGE = ...; {value greater that DUT aging time} 1060 MAX = ...; {maximum address support by implementation} 1061 VARIABLE 1062 LOW := 0; {Highest passed valve} 1063 HIGH := MAX; {Lowest failed value} 1064 N := ...; {user specified initial starting point} 1065 BEGIN 1066 DO 1067 BEGIN 1068 PAUSE(AGE); {Age out any learned addresses} 1069 AddressLearning(TPort); {broadcast a frame with its source 1070 Address and broadcast destination} 1071 AddressLearning(LPort); {N frames with varying source 1072 addresses 1073 to Test Port} 1074 Transmit(TPort); {N frames with varying destination addresses 1075 corresponding to Learning Port} 1076 IF (MPort receive frame != 0) OR 1077 (LPort receive frames < TPort transmit) THEN 1078 BEGIN {Address Table of DUT/SUT was full} 1079 HIGH := N; 1080 END 1081 ELSE 1082 BEGIN {Address Table of DUT/SUT was NOT full} 1083 LOW := N; 1084 END 1085 N := LOW + (HIGH - LOW)/2; 1086 END WHILE (HIGH - LOW < 2); 1087 END {Value of N equals number of addresses supported by DUT/SUT} 1089 Using a binary search approach, the test targets the exact number of 1090 addresses supported per port with consistent test iterations. Due 1091 to the aging time of DUT/SUT address tables, each iteration may take 1092 some time during the waiting period for the addresses to clear. If 1093 possible, configure the DUT/SUT for a low value for the aging time. 1095 Once the high and low values of N meet, then the threshold of address 1096 handling has been found. 1098 5.7.4 Measurements 1100 Whether the offered addresses per port was successful forwarded 1101 without flooding. 1103 5.7.5 Reporting format 1105 After the test is run, results for each iteration SHOULD be displayed 1106 in a table to include: 1108 The number of addresses used for each test iteration (varied). 1110 The intended load used for each test iteration (fixed). 1112 Number of test frames that were offered to Tport of the DUT/SUT. 1113 This SHOULD match the number of addresses used for the test 1114 iteration. Test frames are the frames sent with varying 1115 destination addresses to confirm that the DUT/SUT has learned 1116 all of the addresses for each test iteration. 1118 The flood count on Tport during the test portion of each test. 1119 If the number is non-zero, this is an indication of the DUT/SUT 1120 flooding a frame in which the destination address is not in the 1121 address table. 1123 The number of frames correctly forwarded to test Lport during 1124 the test portion of the test. Received frames MUST have the 1125 correct destination MAC address and SHOULD match a signature 1126 field. For a passing test iteration, this number should be equal 1127 to the number of frames transmitted by Tport. 1129 The flood count on Lport during the test portion of each test. 1130 If the number is non-zero, this is an indication of the DUT/SUT 1131 flooding a frame in which the destination address is not in the 1132 address table. 1134 The flood count on Mport. If the value is not zero, then this 1135 indicates that for that test iteration, the DUT/SUT could not 1136 determine the proper destination port for that many frames. In 1137 other words, the DUT/SUT flooded the frame to all ports since its 1138 address table was full. 1140 5.8 Address Learning Rate 1142 5.8.1 Objective 1144 To determine the rate of address learning of a LAN switching device. 1146 5.8.2 Setup Parameters 1148 The following parameters MUST be defined. Each variable is 1149 configured with the following considerations. 1151 Age Time - The maximum time that a DUT/SUT will keep a learned 1152 address in its forwarding table. 1154 Initial Addresses Learning Rate - The starting rate at which new 1155 addresses are offered to the DUT/SUT to be learned. 1157 Number of Addresses - The number of addresses that the DUT/SUT must 1158 learn. The number MUST be between 1 and the maximum number 1159 supported by the implementation. It is recommended no to exceed 1160 the address caching capacity found in section 5.9 1162 5.8.3 Procedure 1164 The aging time of the DUT/SUT MUST be known. The aging time MUST be 1165 longer than the time necessary to produce frames at the specified 1166 rate. If a low frame rate is used for the test, then it may be 1167 possible that sending a large amount of frames may actually take 1168 longer than the aging time. 1170 This test MUST at a minimum be performed in a three-port 1171 configuration in section 5.9.3. The test MAY be expanded to fully 1172 utilized the DUT/SUT in increments of two or three ports. An 1173 increment of two would include an additional Learning port and Test 1174 port. An increment of three would include an additional Learning 1175 port, Test port, and Monitoring port. 1177 An algorithm similar to the one used to determine address caching 1178 capacity can be used to determine the address learning rate. This 1179 test iterates the rate at which address learning frames are offered 1180 by the test device connected to the DUT/SUT. It is recommended to 1181 set the number of addresses offered to the DUT/SUT in this test to 1182 the maximum caching capacity. 1184 The address learning rate might be determined for different numbers 1185 of addresses but in each test run, the number MUST remain constant 1186 and SHOULD be equal to or less than the maximum address caching 1187 capacity. 1189 5.8.4 Measurements 1191 Whether the offered addresses per port were successful forwarded 1192 without flooding at the offered learning rate. 1194 5.8.5 Reporting format 1196 After the test is run, results for each iteration SHOULD be displayed 1197 in a table: 1199 The number of addresses used for each test iteration (fixed). 1201 The intended load used for each test iteration (varied). 1203 Number of test frames that were transmitted by Tport. This SHOULD 1204 match the number of addresses used for the test iteration. Test 1205 frames are the frames sent with varying destination addresses to 1206 confirm that the DUT/SUT has learned all of the addresses for each 1207 test iteration. 1209 The flood count on Tport during the test portion of each test. 1210 If the number is non-zero, this is an indication of the DUT/SUT 1211 flooding a frame in which the destination address is not in the 1212 address table. 1214 The number of frames correctly forwarded to test Lport during 1215 the test portion of the test. Received frames MUST have the 1216 correct destination MAC address and SHOULD match a signature 1217 field. For a passing test iteration, this number should be equal 1218 to the number of frames transmitted by Tport. 1220 The flood count on Lport during the test portion of each test. 1221 If the number is non-zero, this is an indication of the DUT/SUT 1222 flooding a frame in which the destination address is not in the 1223 address table. 1225 The flood count on Mport. If the value is not zero, then this 1226 indicates that for that test iteration, the DUT/SUT could not 1227 determine the proper destination port for that many frames. In 1228 other words, the DUT/SUT flooded the frame to all ports since its 1229 address table was full. 1231 5.9 Errored frames filtering 1233 5.9.1 Objective 1235 The objective of the Errored frames filtering test is to determine 1236 the behavior of the DUT under error or abnormal frame conditions. 1237 The results of the test indicate if the DUT/SUT filters the errors, 1238 or simply propagates the errored frames along to the destination. 1240 5.9.2 Setup Parameters 1242 The following parameters MUST be defined. Each variable is 1243 configured with the following considerations. 1245 ILoad - Intended Load per port is expressed in a percentage of the 1246 medium's maximum theorical load possible. The actual transmitted 1247 frame per second is dependent upon half duplex or full duplex 1248 operation. The test SHOULD be run multiple times with a different 1249 load per port in each case. 1251 Trial Duration - The recommended Trial Duration is 30 seconds. 1252 Trial duration SHOULD be adjustable between 1 and 300 seconds. 1254 5.9.3 Procedure 1256 Each of the illegal frames for Ethernet MUST be checked: 1258 Oversize - The DUT/SUT MAY filter frames larger than 1518 bytes 1259 from being propagated through the DUT/SUT section 4.2.4.2.1 [4]. 1260 Oversized frames transmitted to the DUT/SUT should not be forwarded. 1261 DUT/SUT supporting tagged Frames MAY forward frames up to and 1262 including 1522 bytes long (section 4.2.4.2.1 [5]). 1264 Undersize - The DUT/SUT MUST filter frames less than 64 bytes from 1265 being propagated through the DUT/SUT (section 4.2.4.2.2 [4]). 1266 Undersized frames (or collision fragments) received by the DUT/SUT 1267 must not be forwarded. 1269 CRC Errors - The DUT/SUT MUST filter frames that fail the Frame Check 1270 Sequence Validation (section 4.2.4.1.2 [4]) from being propagated 1271 through the DUT/SUT. Frames with an invalid CRC transmitted to the 1272 DUT/SUT should not be forwarded. 1274 Dribble Bit Errors - The DUT/SUT MUST correct and forward frames 1275 containing dribbling bits. Frames transmitted to the DUT/SUT that do 1276 not end in an octet boundary but contain a valid frame check sequence 1277 MUST be accepted by the DUT/SUT (section 4.2.4.2.1 [4]) and forwarded 1278 to the correct receive port with the frame ending in an octet 1279 boundary (section 3.4 [4]). 1281 Alignment Errors - The DUT/SUT MUST filter frames that fail the Frame 1282 Check Sequence Validation AND do not end in an octet boundary. This 1283 is a combination of a CRC error and a Dribble Bit error. When both 1284 errors are occurring in the same frame, the DUT/SUT MUST determine 1285 the CRC error takes precedence and filters the frame (section 1286 4.2.4.1.2 [4]) from being propagated. 1288 5.9.5 Reporting format 1290 For each of the error conditions in section 5.6.3, a "pass" or "fail" 1291 MUST be reported. Actual frame counts MAY be reported for diagnostic 1292 purposes. 1294 5.10 Broadcast frame Forwarding and Latency 1296 5.10.1 Objective 1298 The objective of the Broadcast Frame Forwarding and Latency Test is 1299 to determine the throughput and latency of the DUT when forwarding 1300 broadcast traffic. The ability to forward broadcast frames will 1301 depend upon a specific function built into the device for that 1302 purpose. It is therefore necessary to determine the ability of 1303 DUT/SUT to handle broadcast frames, since there may be many different 1304 ways of implementing such a function. 1306 5.10.2 Setup Parameters 1308 The following parameters MUST be defined. Each variable is 1309 configured with the following considerations. 1311 Frame Size - Recommended frame sizes are 64, 128, 256, 512, 1024, 1312 1280 and 1518 bytes, per RFC 2544 section 9 [3]. The four CRC 1313 bytes are included in the frame size specified. 1315 Duplex mode - Half duplex or full duplex. 1317 ILoad - Intended Load per port is expressed in a percentage of the 1318 medium's maximum theoretical load, regardless of traffic 1319 orientation or duplex mode. Certain test configurations will 1320 theoretically over-subscribe the DUT/SUT. 1322 ILoad will not over-subscribe the DUT/SUT in this test. 1324 Trial Duration - The recommended Trial Duration is 30 seconds. 1325 Trial duration SHOULD be adjustable between 1 and 300 seconds. 1327 5.10.3 Procedure 1329 For this test, there are two parts to be run. 1331 Broadcast Frame Throughput - This portion of the test uses a single 1332 source test port to transmit test frames with a broadcast address 1333 using the frame specified in RFC 2544 [3]. Selected receive ports 1334 then measure the forwarding rate and Frame loss rate. 1336 Broadcast Frame Latency - This test uses the same setup as the 1337 Broadcast Frame throughput, but instead of a large stream of test 1338 frames being sent, only one test frame is sent and the latency to 1339 each of the receive ports are measured in seconds. 1341 5.10.4 Measurements 1343 Frame loss rate of the DUT/SUT SHOULD be reported as defined in 1344 section 26.3 [3] with the following notes: Frame loss rate SHOULD be 1345 measured at the end of the trial duration. The term "rate", for this 1346 measurement only, does not imply the units in the fashion of "per 1347 second." 1349 Forwarding rate (FR) of the DUT/SUT SHOULD be reported as the number 1350 of test frames per second that the device is observed to successfully 1351 forward to the correct destination interface in response to a 1352 specified Oload. The Oload MUST also be cited. 1354 5.10.5 Reporting format 1356 The results for these tests SHOULD be reported in the form of a 1357 graph. The x coordinate SHOULD be the frame size, the y coordinate 1358 SHOULD be the test results. There SHOULD be at least two lines on 1359 the graph, one plotting the theoretical and one plotting the test 1360 results. 1362 To measure the DUT/SUT's ability to switch traffic while performing 1363 many different address lookups, the number of addresses per port 1364 MAY be increased in a series of tests. 1366 6. Security Considerations 1368 This document does not yet address Security Considerations. 1370 7. References 1372 [1] Bradner, S., Editor, "Benchmarking Terminology for Network 1373 Interconnection Devices", RFC 1242, July 1991. 1375 [2] Mandeville, R., Editor, "Benchmarking Terminology for LAN 1376 Switching Devices", RFC 2285, February 1998. 1378 [3] Bradner, S., Editor, "Benchmarking Methodology for Network 1379 Interconnect Devices", RFC 2544, March 1999. 1381 [4] ANSI/IEEE, "CSMA/CD Access Method and Physical Layer 1382 Specifications," ISO/IEC 8802-3, ISBN 0-7381-0330-6, 1998. 1384 [5] IEEE Draft, "Frame Extensions for Virtual Bridged Local Area 1385 Networks (VLAN) Tagging on 802.3 Networks", 802.3ac/D3.1, 1386 July 1998. 1388 8. Authors' Address 1390 Robert Mandeville 1391 European Network Laboratories (ENL) 1392 2, rue Helene Boucher 1393 87286 Guyancourt Cedex 1394 France 1396 Phone: + 33 1 39 44 12 05 1397 EMail: bob@enl.net 1399 Jerry Perser 1400 Netcom Systems 1401 20550 Nordhoff St. 1402 Chatsworth, CA 91311 1403 USA 1405 Phone: + 1 818 700 5100 1406 Email: jerry_perser@netcomsystems.com 1408 Appendix A: Formulas 1410 A.1 Calculating the InterBurst Gap 1412 IBG is defined in RFC 2285 [2] as the interval between two bursts. 1413 To achieve a desired load, the follow Input Parameter need to be 1414 defined: 1416 LENGTH - Frame size in bytes including the CRC. 1418 LOAD - The intended load in percent. Range is 0 to 100. 1420 BURST - The number of frames in the burst (integer value). 1422 SPEED - media's speed in bits/sec 1423 Ethernet is 10,000,000 bits/sec 1424 Fast Ethernet is 100,000,000 bits/sec 1425 Gigabit Ethernet is 1,000,000,000 bits/sec 1427 IFG - A constant 96 bits for the minimum interframe gap. 1429 The IBG (in seconds) can be calculated: 1431 [(100/LOAD - 1) * BURST * (IFG + 64 + 8*LENGTH)] + IFG 1432 IBG = ----------------------------------------------------------- 1433 SPEED 1435 A.2 Calculating the Number of Bursts for the Trial Duration 1437 The number of burst for the trial duration is rounded up to the 1438 nearest integer number. The follow Input Parameter need to be 1439 defined: 1441 LENGTH - Frame size in bytes including the CRC. 1443 BURST - The number of frames in the burst (integer value). 1445 SPEED - media's speed in bits/sec 1446 Ethernet is 10,000,000 bits/sec 1447 Fast Ethernet is 100,000,000 bits/sec 1448 Gigabit Ethernet is 1,000,000,000 bits/sec 1450 IFG - A constant 96 bits for the minimum interframe gap. 1452 IBG - Found in the above formula 1454 DURATION - Trial duration in seconds. 1456 An intermediate number of the Burst duration needs to be calculated 1457 first: 1459 IFG*(BURST-1) + BURST*(64 + 8*LENGTH) 1460 TXTIME = ----------------------------------------- 1461 SPEED 1463 Number of Burst for the Trial Duration (rounded up): 1465 DURATION 1466 #OFBURSTS = -------------- 1467 (TXTIME + IBG) 1469 Example: 1471 LENGTH = 64 bytes per frame 1472 LOAD = 100 % offered load 1473 BURST = 24 frames per burst 1474 SPEED = 10 Mbits/sec (Ethernet) 1475 DURATION = 10 seconds test 1477 IBG = 1612.8 uS 1478 TXTIME = 1603.2 uS 1479 #OFBURSTS = 3110 1481 Appendix B: Generating Offered Load 1483 In testing, the tester is configured with the Iload (Intended Load) 1484 and measures the Oload (Offered Load). If the DUT/SUT applies 1485 backpressure, then the Iload and the Oload are not the same value. 1486 The question arises, how to generate the Oload? This appendix will 1487 describe two different methods. 1489 Oload is in the units of bits per second. The two methods described 1490 here will hold one unit constant and let the DUT/SUT vary the other 1491 unit. The tester SHOULD specify which method it uses. 1493 B.1 Frame Based Load 1495 Frame based load holds the number of bits constant. The Trial 1496 Duration will vary based upon back pressure. Advantage is 1497 implementation is a simple state machine. Disadvantage is that Oload 1498 needs to be measured independently. 1500 All ports on the tester MUST transmit the exact number of test 1501 frames. The exact number is found by multiplying the Iload by the 1502 Trial Duration. All ports MAY NOT transmit the same number of frames 1503 if their Iload is not the same. An example would be the Partially 1504 meshed overloading test. 1506 All ports SHOULD start transmitting their frames within 1% of the 1507 trial duration. For a trial duration of 30 seconds, all ports SHOULD 1508 have started transmitting frames within 300 milliseconds of each 1509 other. 1511 Oload MUST be measured independent of Iload. The reported Oload 1512 SHOULD be the average during the Trial Duration. If the tester 1513 continues to transmit after the Trial Duration due to back pressure, 1514 Oload MAY be averaged over the entire transmit time. Oload for the 1515 DUT/SUT MUST be the aggregate of all the Oloads per port. Oload per 1516 port MAY be reported for diagnostic purposes. 1518 B.2 Time Based Load 1520 Time based load holds the Trial Duration constant, while allowing the 1521 number of octets transmitted to vary. Advantages are an accurate 1522 Trial Duration and integrated Oload measurement. Disadvantage is 1523 that the starting and stopping of the transmitters MUST be more 1524 accurate. 1526 All ports on the tester are configured to transmit the Iload for an 1527 indefinite amount of time. Each port MUST count the number of 1528 octets successfully transmitted. 1530 All ports MUST start transmitting their frames within 1% of the trial 1531 duration. For a trial duration of 30 seconds, all ports SHOULD have 1532 started transmitting frames within 300 milliseconds of each other. 1534 All ports SHOULD stop transmitting frames after the specified trial 1535 duration, within 100 PPM. The first test frame transmit time minus 1536 the last test frame transmit time SHOULD be within 100 PPM of the 1537 trial duration. Each port's stop time MUST be in reference to its 1538 start time. This trial duration error controls the accuracy of the 1539 Oload measurement and SHOULD be reported with the Oload measurement 1540 in the units of PPM. 1542 Each port is allowed an offset error of 1000 PPM and a trial duration 1543 error of 100 PPM. At what layer the start and stop is initiated is 1544 not defined yet. The layer MUST complete its transmit process when 1545 the stop time is reached (i.e. no fragments, finish the frame). 1547 Oload is found by taking the number of octets successfully 1548 transmitted and dividing by the trial duration. Oload for the 1549 DUT/SUT MUST be the aggregate of all the Oloads per port. Oload per 1550 port MAY be reported for diagnostic purposes.