1 # Copyright (c) 2019 Cisco and/or its affiliates.
2 # Licensed under the Apache License, Version 2.0 (the "License");
3 # you may not use this file except in compliance with the License.
4 # You may obtain a copy of the License at:
6 # http://www.apache.org/licenses/LICENSE-2.0
8 # Unless required by applicable law or agreed to in writing, software
9 # distributed under the License is distributed on an "AS IS" BASIS,
10 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
11 # See the License for the specific language governing permissions and
12 # limitations under the License.
14 """Performance testing traffic generator library."""
16 from robot.api import logger
17 from robot.libraries.BuiltIn import BuiltIn
19 from .DropRateSearch import DropRateSearch
20 from .Constants import Constants
22 from .topology import NodeType
23 from .topology import NodeSubTypeTG
24 from .topology import Topology
25 from .MLRsearch.AbstractMeasurer import AbstractMeasurer
26 from .MLRsearch.MultipleLossRatioSearch import MultipleLossRatioSearch
27 from .MLRsearch.ReceiveRateMeasurement import ReceiveRateMeasurement
28 from .PLRsearch.PLRsearch import PLRsearch
30 __all__ = ['TGDropRateSearchImpl', 'TrafficGenerator', 'OptimizedSearch']
33 class TGDropRateSearchImpl(DropRateSearch):
34 """Drop Rate Search implementation."""
37 super(TGDropRateSearchImpl, self).__init__()
39 def measure_loss(self, rate, frame_size, loss_acceptance,
40 loss_acceptance_type, traffic_type, skip_warmup=False):
41 """Runs the traffic and evaluate the measured results.
43 :param rate: Offered traffic load.
44 :param frame_size: Size of frame.
45 :param loss_acceptance: Permitted drop ratio or frames count.
46 :param loss_acceptance_type: Type of permitted loss.
47 :param traffic_type: Module name as a traffic type identifier.
48 See resources/traffic_profiles/trex for implemented modules.
49 :param skip_warmup: Start TRex without warmup traffic if true.
52 :type loss_acceptance: float
53 :type loss_acceptance_type: LossAcceptanceType
54 :type traffic_type: str
55 :type skip_warmup: bool
56 :returns: Drop threshold exceeded? (True/False)
58 :raises NotImplementedError: If TG is not supported.
59 :raises RuntimeError: If TG is not specified.
61 # we need instance of TrafficGenerator instantiated by Robot Framework
62 # to be able to use trex_stl-*()
63 tg_instance = BuiltIn().get_library_instance(
64 'resources.libraries.python.TrafficGenerator')
66 if tg_instance.node['subtype'] is None:
67 raise RuntimeError('TG subtype not defined')
68 elif tg_instance.node['subtype'] == NodeSubTypeTG.TREX:
69 unit_rate = str(rate) + self.get_rate_type_str()
71 tg_instance.trex_stl_start_remote_exec(self.get_duration(),
72 unit_rate, frame_size,
76 tg_instance.trex_stl_start_remote_exec(self.get_duration(),
77 unit_rate, frame_size,
79 loss = tg_instance.get_loss()
80 sent = tg_instance.get_sent()
81 if self.loss_acceptance_type_is_percentage():
82 loss = (float(loss) / float(sent)) * 100
84 logger.trace("comparing: {} < {} {}".format(loss,
86 loss_acceptance_type))
87 if float(loss) > float(loss_acceptance):
92 raise NotImplementedError("TG subtype not supported")
94 def get_latency(self):
95 """Returns min/avg/max latency.
97 :returns: Latency stats.
100 tg_instance = BuiltIn().get_library_instance(
101 'resources.libraries.python.TrafficGenerator')
102 return tg_instance.get_latency_int()
105 class TrafficGenerator(AbstractMeasurer):
106 """Traffic Generator.
108 FIXME: Describe API."""
110 # TODO: Decrease friction between various search and rate provider APIs.
111 # TODO: Remove "trex" from lines which could work with other TGs.
113 # Use one instance of TrafficGenerator for all tests in test suite
114 ROBOT_LIBRARY_SCOPE = 'TEST SUITE'
121 self._received = None
123 # T-REX interface order mapping
124 self._ifaces_reordered = False
125 # Parameters not given by measure().
126 self.frame_size = None
127 self.traffic_type = None
128 self.warmup_time = None
134 :returns: Traffic generator node.
140 """Return number of lost packets.
142 :returns: Number of lost packets.
148 """Return number of sent packets.
150 :returns: Number of sent packets.
155 def get_received(self):
156 """Return number of received packets.
158 :returns: Number of received packets.
161 return self._received
163 def get_latency_int(self):
164 """Return rounded min/avg/max latency.
166 :returns: Latency stats.
171 def initialize_traffic_generator(
172 self, tg_node, tg_if1, tg_if2, tg_if1_adj_node, tg_if1_adj_if,
173 tg_if2_adj_node, tg_if2_adj_if, test_type, tg_if1_dst_mac=None,
174 tg_if2_dst_mac=None):
175 """TG initialization.
177 TODO: Document why do we need (and how do we use) _ifaces_reordered.
179 :param tg_node: Traffic generator node.
180 :param tg_if1: TG - name of first interface.
181 :param tg_if2: TG - name of second interface.
182 :param tg_if1_adj_node: TG if1 adjecent node.
183 :param tg_if1_adj_if: TG if1 adjecent interface.
184 :param tg_if2_adj_node: TG if2 adjecent node.
185 :param tg_if2_adj_if: TG if2 adjecent interface.
186 :param test_type: 'L2', 'L3' or 'L7' - OSI Layer testing type.
187 :param tg_if1_dst_mac: Interface 1 destination MAC address.
188 :param tg_if2_dst_mac: Interface 2 destination MAC address.
192 :type tg_if1_adj_node: dict
193 :type tg_if1_adj_if: str
194 :type tg_if2_adj_node: dict
195 :type tg_if2_adj_if: str
197 :type tg_if1_dst_mac: str
198 :type tg_if2_dst_mac: str
200 :raises RuntimeError: In case of issue during initialization.
202 if tg_node['type'] != NodeType.TG:
203 raise RuntimeError('Node type is not a TG')
206 if tg_node['subtype'] == NodeSubTypeTG.TREX:
210 (ret, _, _) = ssh.exec_command(
211 "sudo -E sh -c '{0}/resources/tools/trex/"
212 "trex_installer.sh {1}'".format(Constants.REMOTE_FW_DIR,
213 Constants.TREX_INSTALL_VERSION),
216 raise RuntimeError('TRex installation failed.')
218 if1_pci = Topology().get_interface_pci_addr(tg_node, tg_if1)
219 if2_pci = Topology().get_interface_pci_addr(tg_node, tg_if2)
220 if1_addr = Topology().get_interface_mac(tg_node, tg_if1)
221 if2_addr = Topology().get_interface_mac(tg_node, tg_if2)
223 if test_type == 'L2':
224 if1_adj_addr = if2_addr
225 if2_adj_addr = if1_addr
226 elif test_type == 'L3':
227 if1_adj_addr = Topology().get_interface_mac(tg_if1_adj_node,
229 if2_adj_addr = Topology().get_interface_mac(tg_if2_adj_node,
231 elif test_type == 'L7':
232 if1_addr = Topology().get_interface_ip4(tg_node, tg_if1)
233 if2_addr = Topology().get_interface_ip4(tg_node, tg_if2)
234 if1_adj_addr = Topology().get_interface_ip4(tg_if1_adj_node,
236 if2_adj_addr = Topology().get_interface_ip4(tg_if2_adj_node,
239 raise ValueError("Unknown Test Type")
241 # in case of switched environment we can override MAC addresses
242 if tg_if1_dst_mac is not None and tg_if2_dst_mac is not None:
243 if1_adj_addr = tg_if1_dst_mac
244 if2_adj_addr = tg_if2_dst_mac
246 if min(if1_pci, if2_pci) != if1_pci:
247 if1_pci, if2_pci = if2_pci, if1_pci
248 if1_addr, if2_addr = if2_addr, if1_addr
249 if1_adj_addr, if2_adj_addr = if2_adj_addr, if1_adj_addr
250 self._ifaces_reordered = True
252 if test_type == 'L2' or test_type == 'L3':
253 (ret, _, _) = ssh.exec_command(
254 "sudo sh -c 'cat << EOF > /etc/trex_cfg.yaml\n"
257 " interfaces: [\"{0}\",\"{1}\"]\n"
259 " - dest_mac: [{2}]\n"
261 " - dest_mac: [{4}]\n"
264 .format(if1_pci, if2_pci,
265 "0x"+if1_adj_addr.replace(":", ",0x"),
266 "0x"+if1_addr.replace(":", ",0x"),
267 "0x"+if2_adj_addr.replace(":", ",0x"),
268 "0x"+if2_addr.replace(":", ",0x")))
269 elif test_type == 'L7':
270 (ret, _, _) = ssh.exec_command(
271 "sudo sh -c 'cat << EOF > /etc/trex_cfg.yaml\n"
274 " interfaces: [\"{0}\",\"{1}\"]\n"
277 " default_gw: [{3}]\n"
279 " default_gw: [{5}]\n"
281 .format(if1_pci, if2_pci,
282 if1_addr, if1_adj_addr,
283 if2_addr, if2_adj_addr))
285 raise ValueError("Unknown Test Type")
287 raise RuntimeError('TRex config generation error')
289 for _ in range(0, 3):
290 # kill TRex only if it is already running
292 "sh -c 'pgrep t-rex && sudo pkill t-rex && sleep 3'")
295 (ret, _, _) = ssh.exec_command(
296 "sh -c 'cd {0}/scripts/ && sudo ./trex-cfg'"\
297 .format(Constants.TREX_INSTALL_DIR))
299 raise RuntimeError('trex-cfg failed')
302 if test_type == 'L2' or test_type == 'L3':
303 (ret, _, _) = ssh.exec_command(
304 "sh -c 'cd {0}/scripts/ && "
305 "sudo nohup ./t-rex-64 -i -c 7 --iom 0 > /tmp/trex.log "
306 "2>&1 &' > /dev/null"\
307 .format(Constants.TREX_INSTALL_DIR))
308 elif test_type == 'L7':
309 (ret, _, _) = ssh.exec_command(
310 "sh -c 'cd {0}/scripts/ && "
311 "sudo nohup ./t-rex-64 --astf -i -c 7 --iom 0 > "
312 "/tmp/trex.log 2>&1 &' > /dev/null"\
313 .format(Constants.TREX_INSTALL_DIR))
315 raise ValueError("Unknown Test Type")
317 ssh.exec_command("sh -c 'cat /tmp/trex.log'")
318 raise RuntimeError('t-rex-64 startup failed')
320 # get TRex server info
321 (ret, _, _) = ssh.exec_command(
323 "{0}/resources/tools/trex/trex_server_info.py'"\
324 .format(Constants.REMOTE_FW_DIR),
327 # If we get info TRex is running
329 # after max retries TRex is still not responding to API
330 # critical error occurred
331 raise RuntimeError('t-rex-64 startup failed')
334 def is_trex_running(node):
335 """Check if TRex is running using pidof.
337 :param node: Traffic generator node.
339 :returns: True if TRex is running otherwise False.
341 :raises RuntimeError: If node type is not a TG.
343 if node['type'] != NodeType.TG:
344 raise RuntimeError('Node type is not a TG')
348 ret, _, _ = ssh.exec_command_sudo("pidof t-rex")
349 return bool(int(ret) == 0)
352 def teardown_traffic_generator(node):
355 :param node: Traffic generator node.
358 :raises RuntimeError: If node type is not a TG,
359 or if TRex teardown fails.
361 if node['type'] != NodeType.TG:
362 raise RuntimeError('Node type is not a TG')
363 if node['subtype'] == NodeSubTypeTG.TREX:
366 (ret, _, _) = ssh.exec_command(
367 "sh -c 'sudo pkill t-rex && sleep 3'")
369 raise RuntimeError('pkill t-rex failed')
372 def trex_stl_stop_remote_exec(node):
373 """Execute script on remote node over ssh to stop running traffic.
375 :param node: TRex generator node.
378 :raises RuntimeError: If stop traffic script fails.
383 (ret, _, _) = ssh.exec_command(
384 "sh -c '{}/resources/tools/trex/"
385 "trex_stateless_stop.py'".format(Constants.REMOTE_FW_DIR))
388 raise RuntimeError('TRex stateless runtime error')
390 def trex_stl_start_remote_exec(
391 self, duration, rate, framesize, traffic_type, async_call=False,
392 latency=True, warmup_time=5.0, unidirection=False, tx_port=0,
394 """Execute script on remote node over ssh to start traffic.
396 :param duration: Time expresed in seconds for how long to send traffic.
397 :param rate: Traffic rate expressed with units (pps, %)
398 :param framesize: L2 frame size to send (without padding and IPG).
399 :param traffic_type: Module name as a traffic type identifier.
400 See resources/traffic_profiles/trex for implemented modules.
401 :param async_call: If enabled then don't wait for all incomming trafic.
402 :param latency: With latency measurement.
403 :param warmup_time: Warmup time period.
404 :param unidirection: Traffic is unidirectional. Default: False
405 :param tx_port: Traffic generator transmit port for first flow.
407 :param rx_port: Traffic generator receive port for first flow.
409 :type duration: float
412 :type traffic_type: str
413 :type async_call: bool
415 :type warmup_time: float
416 :type unidirection: bool
419 :raises RuntimeError: In case of TG driver issue.
422 ssh.connect(self._node)
423 reorder = self._ifaces_reordered # Just to make the next line fit.
424 p_0, p_1 = (rx_port, tx_port) if reorder else (tx_port, rx_port)
426 "sh -c '{tool}/resources/tools/trex/trex_stateless_profile.py"
427 " --profile {prof}/resources/traffic_profiles/trex/{traffic}.py"
428 " --duration {duration} --frame_size {framesize} --rate {rate}"
429 " --warmup_time {warmup} --port_0 {p_0} --port_1 {p_1}").format(
430 tool=Constants.REMOTE_FW_DIR, prof=Constants.REMOTE_FW_DIR,
431 traffic=traffic_type, duration=duration, framesize=framesize,
432 rate=rate, warmup=warmup_time, p_0=p_0, p_1=p_1)
434 command += " --async"
436 command += " --latency"
438 command += " --unidirection"
441 (ret, stdout, _) = ssh.exec_command(
442 command, timeout=float(duration) + 60)
445 raise RuntimeError('TRex stateless runtime error')
448 self._received = None
453 # last line from console output
454 line = stdout.splitlines()[-1]
456 logger.info('TrafficGen result: {0}'.format(self._result))
457 self._received = self._result.split(', ')[1].split('=')[1]
458 self._sent = self._result.split(', ')[2].split('=')[1]
459 self._loss = self._result.split(', ')[3].split('=')[1]
461 self._latency.append(self._result.split(', ')[4].split('=')[1])
462 self._latency.append(self._result.split(', ')[5].split('=')[1])
464 def stop_traffic_on_tg(self):
465 """Stop all traffic on TG.
468 :raises RuntimeError: If TG is not set.
470 if self._node is None:
471 raise RuntimeError("TG is not set")
472 if self._node['subtype'] == NodeSubTypeTG.TREX:
473 self.trex_stl_stop_remote_exec(self._node)
475 def send_traffic_on_tg(
476 self, duration, rate, framesize, traffic_type, warmup_time=5,
477 async_call=False, latency=True, unidirection=False, tx_port=0,
479 """Send traffic from all configured interfaces on TG.
481 Note that bidirectional traffic also contains flows
482 transmitted from rx_port and received in tx_port.
483 But some tests use asymmetric traffic, so those arguments are relevant.
485 Also note that traffic generator uses DPDK driver which might
486 reorder port numbers based on wiring and PCI numbering.
487 This method handles that, so argument values are invariant,
488 but you can see swapped valued in debug logs.
490 TODO: Is it better to have less descriptive argument names
491 just to make them less probable to be viewed as misleading or confusing?
492 See https://gerrit.fd.io/r/#/c/17625/11/resources/libraries/python/TrafficGenerator.py@406
494 :param duration: Duration of test traffic generation in seconds.
495 :param rate: Offered load per interface (e.g. 1%, 3gbps, 4mpps, ...).
496 :param framesize: Frame size (L2) in Bytes.
497 :param traffic_type: Module name as a traffic type identifier.
498 See resources/traffic_profiles/trex for implemented modules.
499 :param warmup_time: Warmup phase in seconds.
500 :param async_call: Async mode.
501 :param latency: With latency measurement.
502 :param unidirection: Traffic is unidirectional. Default: False
503 :param tx_port: Traffic generator transmit port for first flow.
505 :param rx_port: Traffic generator receive port for first flow.
510 :type traffic_type: str
511 :type warmup_time: float
512 :type async_call: bool
514 :type unidirection: bool
519 :raises RuntimeError: If TG is not set, or if node is not TG,
520 or if subtype is not specified.
521 :raises NotImplementedError: If TG is not supported.
526 raise RuntimeError("TG is not set")
528 if node['type'] != NodeType.TG:
529 raise RuntimeError('Node type is not a TG')
531 if node['subtype'] is None:
532 raise RuntimeError('TG subtype not defined')
533 elif node['subtype'] == NodeSubTypeTG.TREX:
534 self.trex_stl_start_remote_exec(
535 duration, rate, framesize, traffic_type, async_call, latency,
536 warmup_time, unidirection, tx_port, rx_port)
538 raise NotImplementedError("TG subtype not supported")
542 def no_traffic_loss_occurred(self):
543 """Fail if loss occurred in traffic run.
546 :raises Exception: If loss occured.
548 if self._loss is None:
549 raise RuntimeError('The traffic generation has not been issued')
550 if self._loss != '0':
551 raise RuntimeError('Traffic loss occurred: {0}'.format(self._loss))
553 def fail_if_no_traffic_forwarded(self):
554 """Fail if no traffic forwarded.
557 :raises Exception: If no traffic forwarded.
559 if self._received is None:
560 raise RuntimeError('The traffic generation has not been issued')
561 if self._received == '0':
562 raise RuntimeError('No traffic forwarded')
564 def partial_traffic_loss_accepted(self, loss_acceptance,
565 loss_acceptance_type):
566 """Fail if loss is higher then accepted in traffic run.
568 :param loss_acceptance: Permitted drop ratio or frames count.
569 :param loss_acceptance_type: Type of permitted loss.
570 :type loss_acceptance: float
571 :type loss_acceptance_type: LossAcceptanceType
573 :raises Exception: If loss is above acceptance criteria.
575 if self._loss is None:
576 raise Exception('The traffic generation has not been issued')
578 if loss_acceptance_type == 'percentage':
579 loss = (float(self._loss) / float(self._sent)) * 100
580 elif loss_acceptance_type == 'frames':
581 loss = float(self._loss)
583 raise Exception('Loss acceptance type not supported')
585 if loss > float(loss_acceptance):
586 raise Exception("Traffic loss {} above loss acceptance: {}".format(
587 loss, loss_acceptance))
589 def set_rate_provider_defaults(self, frame_size, traffic_type,
591 """Store values accessed by measure().
593 :param frame_size: Frame size identifier or value [B].
594 :param traffic_type: Module name as a traffic type identifier.
595 See resources/traffic_profiles/trex for implemented modules.
596 :param warmup_time: Traffic duration before measurement starts [s].
597 :type frame_size: str or int
598 :type traffic_type: str
599 :type warmup_time: float
601 self.frame_size = frame_size
602 self.traffic_type = str(traffic_type)
603 self.warmup_time = float(warmup_time)
605 def measure(self, duration, transmit_rate):
606 """Run bi-directional measurement, parse and return results.
608 :param duration: Trial duration [s].
609 :param transmit_rate: Target bidirectional transmit rate [pps].
610 :type duration: float
611 :type transmit_rate: float
612 :returns: Structure containing the result of the measurement.
613 :rtype: ReceiveRateMeasurement
614 :raises RuntimeError: If TG is not set, or if node is not TG,
615 or if subtype is not specified.
616 :raises NotImplementedError: If TG is not supported.
618 duration = float(duration)
619 transmit_rate = float(transmit_rate)
620 # Trex needs target Tr per stream, but reports aggregate Tx and Dx.
621 unit_rate = str(transmit_rate / 2.0) + "pps"
622 self.send_traffic_on_tg(
623 duration, unit_rate, self.frame_size, self.traffic_type,
624 warmup_time=self.warmup_time, latency=True)
625 transmit_count = int(self.get_sent())
626 loss_count = int(self.get_loss())
627 measurement = ReceiveRateMeasurement(
628 duration, transmit_rate, transmit_count, loss_count)
629 measurement.latency = self.get_latency_int()
633 class OptimizedSearch(object):
634 """Class to be imported as Robot Library, containing a single keyword."""
637 def perform_optimized_ndrpdr_search(
638 frame_size, traffic_type, minimum_transmit_rate,
639 maximum_transmit_rate, packet_loss_ratio=0.005,
640 final_relative_width=0.005, final_trial_duration=30.0,
641 initial_trial_duration=1.0, number_of_intermediate_phases=2,
642 timeout=720.0, doublings=1):
643 """Setup initialized TG, perform optimized search, return intervals.
645 :param frame_size: Frame size identifier or value [B].
646 :param traffic_type: Module name as a traffic type identifier.
647 See resources/traffic_profiles/trex for implemented modules.
648 :param minimum_transmit_rate: Minimal bidirectional
649 target transmit rate [pps].
650 :param maximum_transmit_rate: Maximal bidirectional
651 target transmit rate [pps].
652 :param packet_loss_ratio: Fraction of packets lost, for PDR [1].
653 :param final_relative_width: Final lower bound transmit rate
654 cannot be more distant that this multiple of upper bound [1].
655 :param final_trial_duration: Trial duration for the final phase [s].
656 :param initial_trial_duration: Trial duration for the initial phase
657 and also for the first intermediate phase [s].
658 :param number_of_intermediate_phases: Number of intermediate phases
659 to perform before the final phase [1].
660 :param timeout: The search will fail itself when not finished
661 before this overall time [s].
662 :param doublings: How many doublings to do in external search step.
663 Default 1 is suitable for fairly stable tests,
664 less stable tests might get better overal duration with 2 or more.
665 :type frame_size: str or int
666 :type traffic_type: str
667 :type minimum_transmit_rate: float
668 :type maximum_transmit_rate: float
669 :type packet_loss_ratio: float
670 :type final_relative_width: float
671 :type final_trial_duration: float
672 :type initial_trial_duration: float
673 :type number_of_intermediate_phases: int
676 :returns: Structure containing narrowed down NDR and PDR intervals
677 and their measurements.
679 :raises RuntimeError: If total duration is larger than timeout.
681 # we need instance of TrafficGenerator instantiated by Robot Framework
682 # to be able to use trex_stl-*()
683 tg_instance = BuiltIn().get_library_instance(
684 'resources.libraries.python.TrafficGenerator')
685 tg_instance.set_rate_provider_defaults(frame_size, traffic_type)
686 algorithm = MultipleLossRatioSearch(
687 measurer=tg_instance, final_trial_duration=final_trial_duration,
688 final_relative_width=final_relative_width,
689 number_of_intermediate_phases=number_of_intermediate_phases,
690 initial_trial_duration=initial_trial_duration, timeout=timeout,
692 result = algorithm.narrow_down_ndr_and_pdr(
693 minimum_transmit_rate, maximum_transmit_rate, packet_loss_ratio)
697 def perform_soak_search(
698 frame_size, traffic_type, minimum_transmit_rate,
699 maximum_transmit_rate, plr_target=1e-7, tdpt=0.2,
700 initial_count=50, timeout=1800.0):
701 """Setup initialized TG, perform soak search, return avg and stdev.
703 :param frame_size: Frame size identifier or value [B].
704 :param traffic_type: Module name as a traffic type identifier.
705 See resources/traffic_profiles/trex for implemented modules.
706 :param minimum_transmit_rate: Minimal bidirectional
707 target transmit rate [pps].
708 :param maximum_transmit_rate: Maximal bidirectional
709 target transmit rate [pps].
710 :param plr_target: Fraction of packets lost to achieve [1].
711 :param tdpt: Trial duration per trial.
712 The algorithm linearly increases trial duration with trial number,
713 this is the increment between succesive trials, in seconds.
714 :param initial_count: Offset to apply before the first trial.
715 For example initial_count=50 makes first trial to be 51*tdpt long.
716 This is needed because initial "search" phase of integrator
717 takes significant time even without any trial results.
718 :param timeout: The search will stop after this overall time [s].
719 :type frame_size: str or int
720 :type traffic_type: str
721 :type minimum_transmit_rate: float
722 :type maximum_transmit_rate: float
723 :type plr_target: float
724 :type initial_count: int
726 :returns: Average and stdev of estimated bidirectional rate giving PLR.
727 :rtype: 2-tuple of float
729 tg_instance = BuiltIn().get_library_instance(
730 'resources.libraries.python.TrafficGenerator')
731 tg_instance.set_rate_provider_defaults(frame_size, traffic_type)
732 algorithm = PLRsearch(
733 measurer=tg_instance, trial_duration_per_trial=tdpt,
734 packet_loss_ratio_target=plr_target,
735 trial_number_offset=initial_count, timeout=timeout)
736 result = algorithm.search(minimum_transmit_rate, maximum_transmit_rate)