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diff --git a/docs/user/faq.rst b/docs/user/faq.rst new file mode 100644 index 0000000..014a1ab --- /dev/null +++ b/docs/user/faq.rst @@ -0,0 +1,95 @@ +.. This work is licensed under a Creative Commons Attribution 4.0 International License. +.. SPDX-License-Identifier: CC-BY-4.0 +.. (c) Cisco Systems, Inc + +Frequently Asked Questions +************************** + +General Questions +================= + +Can NFVbench be used without OpenStack +-------------------------------------- +Yes. This can be done using the EXT chain mode, with or without ARP +(depending on whether your systen under test can do routing) and by setting the openrc_file +property to empty in the NFVbench configuration. + +Can NFVbench be used with a different traffic generator than TRex? +------------------------------------------------------------------ +This is possible but requires developing a new python class to manage the new traffic generator interface. + +Can I connect Trex directly to my compute node? +----------------------------------------------- +Yes. + +Can I drive NFVbench using a REST interface? +-------------------------------------------- +NFVbench can run in server mode and accept HTTP requests to run any type of measurement (fixed rate run or NDR_PDR run) +with any run configuration. + +Can I run NFVbench on a Cisco UCS-B series blade? +------------------------------------------------- +Yes provided your UCS-B series server has a Cisco VIC 1340 (with a recent firmware version). +TRex will require VIC firmware version 3.1(2) or higher for blade servers (which supports more filtering capabilities). +In this setting, the 2 physical interfaces for data plane traffic are simply hooked to the UCS-B fabric interconnect (no need to connect to a switch). + +Troubleshooting +=============== + +TrafficClientException: End-to-end connectivity cannot be ensured +------------------------------------------------------------------ +Prior to running a benchmark, NFVbench will make sure that traffic is passing in the service chain by sending a small flow of packets in each direction and verifying that they are received back at the other end. +This exception means that NFVbench cannot pass any traffic in the service chain. + +The most common issues that prevent traffic from passing are: +- incorrect wiring of the NFVbench/TRex interfaces +- incorrect vlan_tagging setting in the NFVbench configuration, this needs to match how the NFVbench ports on the switch are configured (trunk or access port) + + - if the switch port is configured as access port, you must disable vlan_tagging in the NFVbench configuration + - if the switch port is configured as trunk (recommended method), you must enable it + +Issues with high performances at a high line rate +------------------------------------------------- + +Flow statistics and/or latency stream can cause performance issue when testing high line rate. + +Flow statistics implies CPU usage to analyse packets and retrieve statistics. CPU can reach 100% usage when high throughput is tested because only one CPU is used for packet reception in TRex. +The ``--no-flow-stats`` option allows you to disable TRex statistics aggregation during the NFVBench test. +This, will permit to save CPU capabilities used for packet reception. + +Example of use : + +.. code-block:: bash + + nfvbench ``--no-flow-stats`` + + 2019-10-28 10:26:52,099 INFO End-to-end connectivity established + 2019-10-28 10:26:52,127 INFO Cleared all existing streams + 2019-10-28 10:26:52,129 INFO Traffic flow statistics are disabled. + + +Latency streams implies also CPU usage to analyse packets and retrieve latency values. CPU can reach 100% usage when high throughput is tested because only one CPU is used for packet reception in TRex. +The ``--no-latency-streams`` option allows you to disable latency streams during the NFVBench test. +This, will permit to save CPU capabilities used for packet reception but no latency information will be return (to be used only if latency value has no meaning for your test). + +Example of use : + +.. code-block:: bash + + nfvbench ``--no-latency-streams`` + 2019-10-28 10:30:03,955 INFO End-to-end connectivity established + 2019-10-28 10:30:03,982 INFO Cleared all existing streams + 2019-10-28 10:30:03,982 INFO Latency streams are disabled + + +Latency flow statistics implies CPU usage to analyse packets and retrieve statistics. CPU can reach 100% usage when high throughput is tested because only one CPU is used for packet reception in TRex. +The ``--no-latency-stats`` option allows you to disable TRex statistics aggregation for latency packets during the NFVBench test. +This, will permit to save CPU capabilities used for packet reception. + +Example of use : + +.. code-block:: bash + + nfvbench ``--no-latency-stats`` + 2019-10-28 10:28:21,559 INFO Cleared all existing streams + 2019-10-28 10:28:21,567 INFO Latency flow statistics are disabled. |