Moved devguide for consitency with docs dir structure for all testing projects

Updated RFC description based on IETF approval of Internet Draft

Change-Id: Ifd37da946866f350b8968bbbe8c5a3f5ce762cfa
Signed-off-by: Trevor Cooper <trevor.cooper@intel.com>

1 files changed, 881 insertions, 0 deletions

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+.. This work is licensed under a Creative Commons Attribution 4.0 International License.
+.. http://creativecommons.org/licenses/by/4.0
+.. (c) OPNFV, Intel Corporation, AT&T and others.
+
+.. _vsperf-design:
+
+======================
+VSPERF Design Document
+======================
+
+Intended Audience
+=================
+
+This document is intended to aid those who want to modify the vsperf code. Or
+to extend it - for example to add support for new traffic generators,
+deployment scenarios and so on.
+
+Usage
+=====
+
+Example Connectivity to DUT
+---------------------------
+
+Establish connectivity to the VSPERF DUT Linux host. If this is in an OPNFV lab
+following the steps provided by `Pharos <https://www.opnfv.org/community/projects/pharos>`_
+ to `access the POD <https://wiki.opnfv.org/display/pharos/Pharos+Lab+Support>`_
+
+The followign steps establish the VSPERF environment.
+
+Example Command Lines
+---------------------
+
+List all the cli options:
+
+.. code-block:: console
+
+   $ ./vsperf -h
+
+Run all tests that have ``tput`` in their name - ``phy2phy_tput``, ``pvp_tput`` etc.:
+
+.. code-block:: console
+
+   $ ./vsperf --tests 'tput'
+
+As above but override default configuration with settings in '10_custom.conf'.
+This is useful as modifying configuration directly in the configuration files
+in ``conf/NN_*.py`` shows up as changes under git source control:
+
+.. code-block:: console
+
+   $ ./vsperf --conf-file=<path_to_custom_conf>/10_custom.conf --tests 'tput'
+
+Override specific test parameters. Useful for shortening the duration of tests
+for development purposes:
+
+.. code-block:: console
+
+   $ ./vsperf --test-params 'TRAFFICGEN_DURATION=10;TRAFFICGEN_RFC2544_TESTS=1;' \
+                            'TRAFFICGEN_PKT_SIZES=(64,)' pvp_tput
+
+Typical Test Sequence
+=====================
+
+This is a typical flow of control for a test.
+
+.. image:: vsperf.png
+
+.. _design-configuration:
+
+Configuration
+=============
+
+The conf package contains the configuration files (``*.conf``) for all system
+components, it also provides a ``settings`` object that exposes all of these
+settings.
+
+Settings are not passed from component to component. Rather they are available
+globally to all components once they import the conf package.
+
+.. code-block:: python
+
+   from conf import settings
+   ...
+   log_file = settings.getValue('LOG_FILE_DEFAULT')
+
+Settings files (``*.conf``) are valid python code so can be set to complex
+types such as lists and dictionaries as well as scalar types:
+
+.. code-block:: python
+
+   first_packet_size = settings.getValue('PACKET_SIZE_LIST')[0]
+
+Configuration Procedure and Precedence
+--------------------------------------
+
+Configuration files follow a strict naming convention that allows them to be
+processed in a specific order. All the .conf files are named ``NNx_name.conf``,
+where ``NN`` is a decimal number and ``x`` is an optional alphabetical suffix.
+The files are processed in order from ``00_name.conf`` to ``99_name.conf``
+(and from ``00a_name`` to ``00z_name``), so that if the name setting is given
+in both a lower and higher numbered conf file then the higher numbered file
+is the effective setting as it is processed after the setting in the lower
+numbered file.
+
+The values in the file specified by ``--conf-file`` takes precedence over all
+the other configuration files and does not have to follow the naming
+convention.
+
+.. _paths-documentation:
+
+Configuration of PATHS dictionary
+---------------------------------
+
+VSPERF uses external tools like Open vSwitch and Qemu for execution of testcases. These
+tools may be downloaded and built automatically (see :ref:`vsperf-installation-script`)
+or installed manually by user from binary packages. It is also possible to use a combination
+of both approaches, but it is essential to correctly set paths to all required tools.
+These paths are stored within a PATHS dictionary, which is evaluated before execution
+of each testcase, in order to setup testcase specific environment. Values selected for testcase
+execution are internally stored inside TOOLS dictionary, which is used by VSPERF to execute
+external tools, load kernel modules, etc.
+
+The default configuration of PATHS dictionary is spread among three different configuration files
+to follow logical grouping of configuration options. Basic description of PATHS dictionary
+is placed inside ``conf/00_common.conf``. The configuration specific to DPDK and vswitches
+is located at ``conf/02_vswitch.conf``. The last part related to the Qemu is defined inside
+``conf/04_vnf.conf``. Default configuration values can be used in case, that all required
+tools were downloaded and built automatically by vsperf itself. In case, that some of
+tools were installed manually from binary packages, then it will be necessary to modify
+the content of PATHS dictionary accordingly.
+
+Dictionary has a specific section of configuration options for every tool type, it means:
+
+    * ``PATHS['vswitch']`` - contains a separete dictionary for each of vswitches supported by VSPEF
+
+      Example:
+
+      .. code-block:: python
+
+         PATHS['vswitch'] = {
+            'OvsDpdkVhost': { ... },
+            'OvsVanilla' : { ... },
+            ...
+         }
+
+    * ``PATHS['dpdk']`` - contains paths to the dpdk sources, kernel modules and tools (e.g. testpmd)
+
+      Example:
+
+      .. code-block:: python
+
+         PATHS['dpdk'] = {
+            'type' : 'src',
+            'src': {
+                'path': os.path.join(ROOT_DIR, 'src/dpdk/dpdk/'),
+                'modules' : ['uio', os.path.join(RTE_TARGET, 'kmod/igb_uio.ko')],
+                'bind-tool': 'tools/dpdk*bind.py',
+                'testpmd': os.path.join(RTE_TARGET, 'app', 'testpmd'),
+            },
+            ...
+         }
+
+    * ``PATHS['qemu']`` - contains paths to the qemu sources and executable file
+
+      Example:
+
+      .. code-block:: python
+
+         PATHS['qemu'] = {
+             'type' : 'bin',
+             'bin': {
+                 'qemu-system': 'qemu-system-x86_64'
+             },
+             ...
+         }
+
+Every section specific to the particular vswitch, dpdk or qemu may contain following types
+of configuration options:
+
+    * option ``type`` - is a string, which defines the type of configured paths ('src' or 'bin')
+      to be selected for a given section:
+
+        * value ``src`` means, that VSPERF will use vswitch, DPDK or QEMU built from sources
+          e.g. by execution of ``systems/build_base_machine.sh`` script during VSPERF
+          installation
+
+        * value ``bin`` means, that VSPERF will use vswitch, DPDK or QEMU binaries installed
+          directly in the operating system, e.g. via OS specific packaging system
+
+    * option ``path`` - is a string with a valid system path; Its content is checked for
+      existence, prefixed with section name and stored into TOOLS for later use
+      e.g. ``TOOLS['dpdk_src']`` or ``TOOLS['vswitch_src']``
+
+    * option ``modules`` - is list of strings with names of kernel modules; Every module name
+      from given list is checked for a '.ko' suffix. In case that it matches and if it is not
+      an absolute path to the module, then module name is prefixed with value of ``path``
+      option defined for the same section
+
+      Example:
+
+      .. code-block:: python
+
+         """
+         snippet of PATHS definition from the configuration file:
+         """
+         PATHS['vswitch'] = {
+             'OvsVanilla' = {
+                 'type' : 'src',
+                 'src': {
+                     'path': '/tmp/vsperf/src_vanilla/ovs/ovs/',
+                     'modules' : ['datapath/linux/openvswitch.ko'],
+                     ...
+                 },
+                 ...
+             }
+             ...
+         }
+
+         """
+         Final content of TOOLS dictionary used during runtime:
+         """
+         TOOLS['vswitch_modules'] = ['/tmp/vsperf/src_vanilla/ovs/ovs/datapath/linux/openvswitch.ko']
+
+    * all other options are strings with names and paths to specific tools; If a given string
+      contains a relative path and option ``path`` is defined for a given section, then string
+      content will be prefixed with content of the ``path``. Otherwise the name of the tool will be
+      searched within standard system directories. In case that filename contains OS specific
+      wildcards, then they will be expanded to the real path. At the end of the processing, every
+      absolute path will be checked for its existence. In case that temporary path (i.e. path with
+      a ``_tmp`` suffix) does not exist, then log will be written and vsperf will continue. If any
+      other path will not exist, then vsperf execution will be terminated with a runtime error.
+
+      Example:
+
+      .. code-block:: python
+
+         """
+         snippet of PATHS definition from the configuration file:
+         """
+         PATHS['vswitch'] = {
+             'OvsDpdkVhost': {
+                 'type' : 'src',
+                 'src': {
+                     'path': '/tmp/vsperf/src_vanilla/ovs/ovs/',
+                     'ovs-vswitchd': 'vswitchd/ovs-vswitchd',
+                     'ovsdb-server': 'ovsdb/ovsdb-server',
+                     ...
+                 }
+                 ...
+             }
+             ...
+         }
+
+         """
+         Final content of TOOLS dictionary used during runtime:
+         """
+         TOOLS['ovs-vswitchd'] = '/tmp/vsperf/src_vanilla/ovs/ovs/vswitchd/ovs-vswitchd'
+         TOOLS['ovsdb-server'] = '/tmp/vsperf/src_vanilla/ovs/ovs/ovsdb/ovsdb-server'
+
+Note: In case that ``bin`` type is set for DPDK, then ``TOOLS['dpdk_src']`` will be set to
+the value of ``PATHS['dpdk']['src']['path']``. The reason is, that VSPERF uses downloaded
+DPDK sources to copy DPDK and testpmd into the GUEST, where testpmd is built. In case,
+that DPDK sources are not available, then vsperf will continue with test execution,
+but testpmd can't be used as a guest loopback. This is useful in case, that other guest
+loopback applications (e.g. buildin or l2fwd) are used.
+
+Note: In case of RHEL 7.3 OS usage, binary package configuration is required
+for Vanilla OVS tests. With the installation of a supported rpm for OVS there is
+a section in the ``conf\10_custom.conf`` file that can be used.
+
+.. _configuration-of-traffic-dictionary:
+
+Configuration of TRAFFIC dictionary
+-----------------------------------
+
+TRAFFIC dictionary is used for configuration of traffic generator. Default values
+can be found in configuration file ``conf/03_traffic.conf``. These default values
+can be modified by (first option has the highest priorty):
+
+    1. ``Parameters`` section of testcase defintion
+    2. command line options specified by ``--test-params`` argument
+    3. custom configuration file
+
+It is to note, that in case of option 1 and 2, it is possible to specify only
+values, which should be changed. In case of custom configuration file, it is
+required to specify whole ``TRAFFIC`` dictionary with its all values or explicitly
+call and update() method of ``TRAFFIC`` dictionary.
+
+Detailed description of ``TRAFFIC`` dictionary items follows:
+
+.. code-block:: console
+
+    'traffic_type'  - One of the supported traffic types.
+                      E.g. rfc2544_throughput, rfc2544_back2back
+                      or rfc2544_continuous
+                      Data type: str
+                      Default value: "rfc2544_throughput".
+    'bidir'         - Specifies if generated traffic will be full-duplex (True)
+                      or half-duplex (False)
+                      Data type: str
+                      Supported values: "True", "False"
+                      Default value: "False".
+    'frame_rate'    - Defines desired percentage of frame rate used during
+                      continuous stream tests.
+                      Data type: int
+                      Default value: 100.
+    'multistream'   - Defines number of flows simulated by traffic generator.
+                      Value 0 disables multistream feature
+                      Data type: int
+                      Supported values: 0-65536 for 'L4' stream type
+                                        unlimited for 'L2' and 'L3' stream types
+                      Default value: 0.
+    'stream_type'   - Stream type is an extension of the "multistream" feature.
+                      If multistream is disabled, then stream type will be
+                      ignored. Stream type defines ISO OSI network layer used
+                      for simulation of multiple streams.
+                      Data type: str
+                      Supported values:
+                         "L2" - iteration of destination MAC address
+                         "L3" - iteration of destination IP address
+                         "L4" - iteration of destination port
+                                of selected transport protocol
+                      Default value: "L4".
+    'pre_installed_flows'
+                   -  Pre-installed flows is an extension of the "multistream"
+                      feature. If enabled, it will implicitly insert a flow
+                      for each stream. If multistream is disabled, then
+                      pre-installed flows will be ignored.
+                      Note: It is supported only for p2p deployment scenario.
+                      Data type: str
+                      Supported values:
+                         "Yes" - flows will be inserted into OVS
+                         "No"  - flows won't be inserted into OVS
+                      Default value: "No".
+    'flow_type'     - Defines flows complexity.
+                      Data type: str
+                      Supported values:
+                         "port" - flow is defined by ingress ports
+                         "IP"   - flow is defined by ingress ports
+                                  and src and dst IP addresses
+                      Default value: "port"
+    'l2'            - A dictionary with l2 network layer details. Supported
+                      values are:
+        'srcmac'    - Specifies source MAC address filled by traffic generator.
+                      NOTE: It can be modified by vsperf in some scenarios.
+                      Data type: str
+                      Default value: "00:00:00:00:00:00".
+        'dstmac'    - Specifies destination MAC address filled by traffic generator.
+                      NOTE: It can be modified by vsperf in some scenarios.
+                      Data type: str
+                      Default value: "00:00:00:00:00:00".
+        'framesize' - Specifies default frame size. This value should not be
+                      changed directly. It will be overridden during testcase
+                      execution by values specified by list TRAFFICGEN_PKT_SIZES.
+                      Data type: int
+                      Default value: 64
+    'l3'            - A dictionary with l3 network layer details. Supported
+                      values are:
+        'enabled'   - Specifies if l3 layer should be enabled or disabled.
+                      Data type: bool
+                      Default value: True
+                      NOTE: Supported only by IxNet trafficgen class
+        'srcip'     - Specifies source MAC address filled by traffic generator.
+                      NOTE: It can be modified by vsperf in some scenarios.
+                      Data type: str
+                      Default value: "1.1.1.1".
+        'dstip'     - Specifies destination MAC address filled by traffic generator.
+                      NOTE: It can be modified by vsperf in some scenarios.
+                      Data type: str
+                      Default value: "90.90.90.90".
+        'proto'     - Specifies deflaut protocol type.
+                      Please check particular traffic generator implementation
+                      for supported protocol types.
+                      Data type: str
+                      Default value: "udp".
+    'l4'            - A dictionary with l4 network layer details. Supported
+                      values are:
+        'enabled'   - Specifies if l4 layer should be enabled or disabled.
+                      Data type: bool
+                      Default value: True
+                      NOTE: Supported only by IxNet trafficgen class
+        'srcport'   - Specifies source port of selected transport protocol.
+                      NOTE: It can be modified by vsperf in some scenarios.
+                      Data type: int
+                      Default value: 3000
+        'dstport'   - Specifies destination port of selected transport protocol.
+                      NOTE: It can be modified by vsperf in some scenarios.
+                      Data type: int
+                      Default value: 3001
+    'vlan'          - A dictionary with vlan encapsulation details. Supported
+                      values are:
+        'enabled'   - Specifies if vlan encapsulation should be enabled or
+                      disabled.
+                      Data type: bool
+                      Default value: False
+        'id'        - Specifies vlan id.
+                      Data type: int (NOTE: must fit to 12 bits)
+                      Default value: 0
+        'priority'  - Specifies a vlan priority (PCP header field).
+                      Data type: int (NOTE: must fit to 3 bits)
+                      Default value: 0
+        'cfi'       - Specifies if frames can or cannot be dropped during
+                      congestion (DEI header field).
+                      Data type: int (NOTE: must fit to 1 bit)
+                      Default value: 0
+
+.. _configuration-of-guest-options:
+
+Configuration of GUEST options
+------------------------------
+
+VSPERF is able to setup scenarios involving a number of VMs in series or in parallel.
+All configuration options related to a particular VM instance are defined as
+lists and prefixed with ``GUEST_`` label. It is essential, that there is enough
+items in all ``GUEST_`` options to cover all VM instances involved in the test.
+In case there is not enough items, then VSPERF will use the first item of
+particular ``GUEST_`` option to expand the list to required length.
+
+Example of option expansion for 4 VMs:
+
+    .. code-block:: python
+
+       """
+       Original values:
+       """
+       GUEST_SMP = ['2']
+       GUEST_MEMORY = ['2048', '4096']
+
+       """
+       Values after automatic expansion:
+       """
+       GUEST_SMP = ['2', '2', '2', '2']
+       GUEST_MEMORY = ['2048', '4096', '2048', '2048']
+
+
+First option can contain macros starting with ``#`` to generate VM specific values.
+These macros can be used only for options of ``list`` or ``str`` types with ``GUEST_``
+prefix.
+
+Example of macros and their expnasion for 2 VMs:
+
+    .. code-block:: python
+
+       """
+       Original values:
+       """
+       GUEST_SHARE_DIR = ['/tmp/qemu#VMINDEX_share']
+       GUEST_BRIDGE_IP = ['#IP(1.1.1.5)/16']
+
+       """
+       Values after automatic expansion:
+       """
+       GUEST_SHARE_DIR = ['/tmp/qemu0_share', '/tmp/qemu1_share']
+       GUEST_BRIDGE_IP = ['1.1.1.5/16', '1.1.1.6/16']
+
+Additional examples are available at ``04_vnf.conf``.
+
+Note: In  case, that macro is detected in the first item of the list, then
+all other items are ignored and list content is created automatically.
+
+Multiple macros can be used inside one configuration option definition, but macros
+cannot be used inside other macros. The only exception is macro ``#VMINDEX``, which
+is expanded first and thus it can be used inside other macros.
+
+Following macros are supported:
+
+  * ``#VMINDEX`` - it is replaced by index of VM being executed; This macro
+    is expanded first, so it can be used inside other macros.
+
+    Example:
+
+    .. code-block:: python
+
+       GUEST_SHARE_DIR = ['/tmp/qemu#VMINDEX_share']
+
+  * ``#MAC(mac_address[, step])`` - it will iterate given ``mac_address``
+    with optional ``step``. In case that step is not defined, then it is set to 1.
+    It means, that first VM will use the value of ``mac_address``, second VM
+    value of ``mac_address`` increased by ``step``, etc.
+
+    Example:
+
+    .. code-block:: python
+
+       GUEST_NICS = [[{'mac' : '#MAC(00:00:00:00:00:01,2)'}]]
+
+  * ``#IP(ip_address[, step])`` - it will iterate given ``ip_address``
+    with optional ``step``. In case that step is not defined, then it is set to 1.
+    It means, that first VM will use the value of ``ip_address``, second VM
+    value of ``ip_address`` increased by ``step``, etc.
+
+    Example:
+
+    .. code-block:: python
+
+       GUEST_BRIDGE_IP = ['#IP(1.1.1.5)/16']
+
+  * ``#EVAL(expression)`` - it will evaluate given ``expression`` as python code;
+    Only simple expressions should be used. Call of the functions is not supported.
+
+    Example:
+
+    .. code-block:: python
+
+       GUEST_CORE_BINDING = [('#EVAL(6+2*#VMINDEX)', '#EVAL(7+2*#VMINDEX)')]
+
+Other Configuration
+-------------------
+
+``conf.settings`` also loads configuration from the command line and from the environment.
+
+.. _pxp-deployment:
+
+PXP Deployment
+==============
+
+Every testcase uses one of the supported deployment scenarios to setup test environment.
+The controller responsible for a given scenario configures flows in the vswitch to route
+traffic among physical interfaces connected to the traffic generator and virtual
+machines. VSPERF supports several deployments including PXP deployment, which can
+setup various scenarios with multiple VMs.
+
+These scenarios are realized by VswitchControllerPXP class, which can configure and
+execute given number of VMs in serial or parallel configurations. Every VM can be
+configured with just one or an even number of interfaces. In case that VM has more than
+2 interfaces, then traffic is properly routed among pairs of interfaces.
+
+Example of traffic routing for VM with 4 NICs in serial configuration:
+
+.. code-block:: console
+
+                 +------------------------------------------+
+                 |  VM with 4 NICs                          |
+                 |  +---------------+    +---------------+  |
+                 |  |  Application  |    |  Application  |  |
+                 |  +---------------+    +---------------+  |
+                 |      ^       |            ^       |      |
+                 |      |       v            |       v      |
+                 |  +---------------+    +---------------+  |
+                 |  | logical ports |    | logical ports |  |
+                 |  |   0       1   |    |   2       3   |  |
+                 +--+---------------+----+---------------+--+
+                        ^       :            ^       :
+                        |       |            |       |
+                        :       v            :       v
+        +-----------+---------------+----+---------------+----------+
+        | vSwitch   |   0       1   |    |   2       3   |          |
+        |           | logical ports |    | logical ports |          |
+        | previous  +---------------+    +---------------+   next   |
+        | VM or PHY     ^       |            ^       |     VM or PHY|
+        |   port   -----+       +------------+       +--->   port   |
+        +-----------------------------------------------------------+
+
+It is also possible to define different number of interfaces for each VM to better
+simulate real scenarios.
+
+Example of traffic routing for 2 VMs in serial configuration, where 1st VM has
+4 NICs and 2nd VM 2 NICs:
+
+.. code-block:: console
+
+           +------------------------------------------+  +---------------------+
+           |  1st VM with 4 NICs                      |  |  2nd VM with 2 NICs |
+           |  +---------------+    +---------------+  |  |  +---------------+  |
+           |  |  Application  |    |  Application  |  |  |  |  Application  |  |
+           |  +---------------+    +---------------+  |  |  +---------------+  |
+           |      ^       |            ^       |      |  |      ^       |      |
+           |      |       v            |       v      |  |      |       v      |
+           |  +---------------+    +---------------+  |  |  +---------------+  |
+           |  | logical ports |    | logical ports |  |  |  | logical ports |  |
+           |  |   0       1   |    |   2       3   |  |  |  |   0       1   |  |
+           +--+---------------+----+---------------+--+  +--+---------------+--+
+                  ^       :            ^       :               ^       :
+                  |       |            |       |               |       |
+                  :       v            :       v               :       v
+  +-----------+---------------+----+---------------+-------+---------------+----------+
+  | vSwitch   |   0       1   |    |   2       3   |       |   4       5   |          |
+  |           | logical ports |    | logical ports |       | logical ports |          |
+  | previous  +---------------+    +---------------+       +---------------+   next   |
+  | VM or PHY     ^       |            ^       |               ^       |     VM or PHY|
+  |   port   -----+       +------------+       +---------------+       +---->  port   |
+  +-----------------------------------------------------------------------------------+
+
+The number of VMs involved in the test and the type of their connection is defined
+by deployment name as follows:
+
+  * ``pvvp[number]`` - configures scenario with VMs connected in series with
+    optional ``number`` of VMs. In case that ``number`` is not specified, then
+    2 VMs will be used.
+
+    Example of 2 VMs in a serial configuration:
+
+    .. code-block:: console
+
+       +----------------------+  +----------------------+
+       |   1st VM             |  |   2nd VM             |
+       |   +---------------+  |  |   +---------------+  |
+       |   |  Application  |  |  |   |  Application  |  |
+       |   +---------------+  |  |   +---------------+  |
+       |       ^       |      |  |       ^       |      |
+       |       |       v      |  |       |       v      |
+       |   +---------------+  |  |   +---------------+  |
+       |   | logical ports |  |  |   | logical ports |  |
+       |   |   0       1   |  |  |   |   0       1   |  |
+       +---+---------------+--+  +---+---------------+--+
+               ^       :                 ^       :
+               |       |                 |       |
+               :       v                 :       v
+       +---+---------------+---------+---------------+--+
+       |   |   0       1   |         |   3       4   |  |
+       |   | logical ports | vSwitch | logical ports |  |
+       |   +---------------+         +---------------+  |
+       |       ^       |                 ^       |      |
+       |       |       +-----------------+       v      |
+       |   +----------------------------------------+   |
+       |   |              physical ports            |   |
+       |   |      0                         1       |   |
+       +---+----------------------------------------+---+
+                  ^                         :
+                  |                         |
+                  :                         v
+       +------------------------------------------------+
+       |                                                |
+       |                traffic generator               |
+       |                                                |
+       +------------------------------------------------+
+
+  * ``pvpv[number]`` - configures scenario with VMs connected in parallel with
+    optional ``number`` of VMs. In case that ``number`` is not specified, then
+    2 VMs will be used. Multistream feature is used to route traffic to particular
+    VMs (or NIC pairs of every VM). It means, that VSPERF will enable multistream
+    feaure and sets the number of streams to the number of VMs and their NIC
+    pairs. Traffic will be dispatched based on Stream Type, i.e. by UDP port,
+    IP address or MAC address.
+
+    Example of 2 VMs in a parallel configuration, where traffic is dispatched
+        based on the UDP port.
+
+    .. code-block:: console
+
+       +----------------------+  +----------------------+
+       |   1st VM             |  |   2nd VM             |
+       |   +---------------+  |  |   +---------------+  |
+       |   |  Application  |  |  |   |  Application  |  |
+       |   +---------------+  |  |   +---------------+  |
+       |       ^       |      |  |       ^       |      |
+       |       |       v      |  |       |       v      |
+       |   +---------------+  |  |   +---------------+  |
+       |   | logical ports |  |  |   | logical ports |  |
+       |   |   0       1   |  |  |   |   0       1   |  |
+       +---+---------------+--+  +---+---------------+--+
+               ^       :                 ^       :
+               |       |                 |       |
+               :       v                 :       v
+       +---+---------------+---------+---------------+--+
+       |   |   0       1   |         |   3       4   |  |
+       |   | logical ports | vSwitch | logical ports |  |
+       |   +---------------+         +---------------+  |
+       |      ^         |                 ^       :     |
+       |      |     ......................:       :     |
+       |  UDP | UDP :   |                         :     |
+       |  port| port:   +--------------------+    :     |
+       |   0  |  1  :                        |    :     |
+       |      |     :                        v    v     |
+       |   +----------------------------------------+   |
+       |   |              physical ports            |   |
+       |   |    0                               1   |   |
+       +---+----------------------------------------+---+
+                ^                               :
+                |                               |
+                :                               v
+       +------------------------------------------------+
+       |                                                |
+       |                traffic generator               |
+       |                                                |
+       +------------------------------------------------+
+
+
+PXP deployment is backward compatible with PVP deployment, where ``pvp`` is
+an alias for ``pvvp1`` and it executes just one VM.
+
+The number of interfaces used by VMs is defined by configuration option
+``GUEST_NICS_NR``. In case that more than one pair of interfaces is defined
+for VM, then:
+
+    * for ``pvvp`` (serial) scenario every NIC pair is connected in serial
+      before connection to next VM is created
+    * for ``pvpv`` (parallel) scenario every NIC pair is directly connected
+      to the physical ports and unique traffic stream is assigned to it
+
+Examples:
+
+    * Deployment ``pvvp10`` will start 10 VMs and connects them in series
+    * Deployment ``pvpv4`` will start 4 VMs and connects them in parallel
+    * Deployment ``pvpv1`` and GUEST_NICS_NR = [4] will start 1 VM with
+      4 interfaces and every NIC pair is directly connected to the
+      physical ports
+    * Deployment ``pvvp`` and GUEST_NICS_NR = [2, 4] will start 2 VMs;
+      1st VM will have 2 interfaces and 2nd VM 4 interfaces. These interfaces
+      will be connected in serial, i.e. traffic will flow as follows:
+      PHY1 -> VM1_1 -> VM1_2 -> VM2_1 -> VM2_2 -> VM2_3 -> VM2_4 -> PHY2
+
+Note: In case that only 1 or more than 2 NICs are configured for VM,
+then ``testpmd`` should be used as forwarding application inside the VM.
+As it is able to forward traffic between multiple VM NIC pairs.
+
+Note: In case of ``linux_bridge``, all NICs are connected to the same
+bridge inside the VM.
+
+VM, vSwitch, Traffic Generator Independence
+===========================================
+
+VSPERF supports different vSwithes, Traffic Generators, VNFs
+and Forwarding Applications by using standard object-oriented polymorphism:
+
+  * Support for vSwitches is implemented by a class inheriting from IVSwitch.
+  * Support for Traffic Generators is implemented by a class inheriting from
+    ITrafficGenerator.
+  * Support for VNF is implemented by a class inheriting from IVNF.
+  * Support for Forwarding Applications is implemented by a class inheriting
+    from IPktFwd.
+
+By dealing only with the abstract interfaces the core framework can support
+many implementations of different vSwitches, Traffic Generators, VNFs
+and Forwarding Applications.
+
+IVSwitch
+--------
+
+.. code-block:: python
+
+    class IVSwitch:
+      start(self)
+      stop(self)
+      add_switch(switch_name)
+      del_switch(switch_name)
+      add_phy_port(switch_name)
+      add_vport(switch_name)
+      get_ports(switch_name)
+      del_port(switch_name, port_name)
+      add_flow(switch_name, flow)
+      del_flow(switch_name, flow=None)
+
+ITrafficGenerator
+-----------------
+
+.. code-block:: python
+
+    class ITrafficGenerator:
+      connect()
+      disconnect()
+
+      send_burst_traffic(traffic, numpkts, time, framerate)
+
+      send_cont_traffic(traffic, time, framerate)
+      start_cont_traffic(traffic, time, framerate)
+      stop_cont_traffic(self):
+
+      send_rfc2544_throughput(traffic, tests, duration, lossrate)
+      start_rfc2544_throughput(traffic, tests, duration, lossrate)
+      wait_rfc2544_throughput(self)
+
+      send_rfc2544_back2back(traffic, tests, duration, lossrate)
+      start_rfc2544_back2back(traffic, , tests, duration, lossrate)
+      wait_rfc2544_back2back()
+
+Note ``send_xxx()`` blocks whereas ``start_xxx()`` does not and must be followed by a subsequent call to ``wait_xxx()``.
+
+IVnf
+----
+
+.. code-block:: python
+
+    class IVnf:
+      start(memory, cpus,
+            monitor_path, shared_path_host,
+            shared_path_guest, guest_prompt)
+      stop()
+      execute(command)
+      wait(guest_prompt)
+      execute_and_wait (command)
+
+IPktFwd
+--------
+
+  .. code-block:: python
+
+    class IPktFwd:
+        start()
+        stop()
+
+
+Controllers
+-----------
+
+Controllers are used in conjunction with abstract interfaces as way
+of decoupling the control of vSwtiches, VNFs, TrafficGenerators
+and Forwarding Applications from other components.
+
+The controlled classes provide basic primitive operations. The Controllers
+sequence and co-ordinate these primitive operation in to useful actions. For
+instance the vswitch_controller_p2p can be used to bring any vSwitch (that
+implements the primitives defined in IVSwitch) into the configuration required
+by the Phy-to-Phy  Deployment Scenario.
+
+In order to support a new vSwitch only a new implementation of IVSwitch needs
+be created for the new vSwitch to be capable of fulfilling all the Deployment
+Scenarios provided for by existing or future vSwitch Controllers.
+
+Similarly if a new Deployment Scenario is required it only needs to be written
+once as a new vSwitch Controller and it will immediately be capable of
+controlling all existing and future vSwitches in to that Deployment Scenario.
+
+Similarly the Traffic Controllers can be used to co-ordinate basic operations
+provided by implementers of ITrafficGenerator to provide useful tests. Though
+traffic generators generally already implement full test cases i.e. they both
+generate suitable traffic and analyse returned traffic in order to implement a
+test which has typically been predefined in an RFC document. However the
+Traffic Controller class allows for the possibility of further enhancement -
+such as iterating over tests for various packet sizes or creating new tests.
+
+Traffic Controller's Role
+-------------------------
+
+.. image:: traffic_controller.png
+
+
+Loader & Component Factory
+--------------------------
+
+The working of the Loader package (which is responsible for *finding* arbitrary
+classes based on configuration data) and the Component Factory which is
+responsible for *choosing* the correct class for a particular situation - e.g.
+Deployment Scenario can be seen in this diagram.
+
+.. image:: factory_and_loader.png
+
+Routing Tables
+==============
+
+Vsperf uses a standard set of routing tables in order to allow tests to easily
+mix and match Deployment Scenarios (PVP, P2P topology), Tuple Matching and
+Frame Modification requirements.
+
+.. code-block:: console
+
+      +--------------+
+      |              |
+      | Table 0      |  table#0 - Match table. Flows designed to force 5 & 10
+      |              |  tuple matches go here.
+      |              |
+      +--------------+
+             |
+             |
+             v
+      +--------------+  table#1 - Routing table. Flow entries to forward
+      |              |  packets between ports goes here.
+      | Table 1      |  The chosen port is communicated to subsequent tables by
+      |              |  setting the metadata value to the egress port number.
+      |              |  Generally this table is set-up by by the
+      +--------------+  vSwitchController.
+             |
+             |
+             v
+      +--------------+  table#2 - Frame modification table. Frame modification
+      |              |  flow rules are isolated in this table so that they can
+      | Table 2      |  be turned on or off without affecting the routing or
+      |              |  tuple-matching flow rules. This allows the frame
+      |              |  modification and tuple matching required by the tests
+      |              |  in the VSWITCH PERFORMANCE FOR TELCO NFV test
+      +--------------+  specification to be independent of the Deployment
+             |          Scenario set up by the vSwitchController.
+             |
+             v
+      +--------------+
+      |              |
+      | Table 3      |  table#3 - Egress table. Egress packets on the ports
+      |              |  setup in Table 1.
+      +--------------+
+
+