+
+Card Bandwidth Options
+~~~~~~~~~~~~~~~~~~~~~~
+
+T-Rex API will attempt to retrieve the highest possible speed from the card using internal
+calls to port information. If you are using two separate cards then it will take the lowest
+of the two cards as the max speed. If necessary you can try to force the API to use a
+specific maximum speed per port. The below configurations can be adjusted to enable this.
+
+.. code-block:: console
+
+ TRAFFICGEN_TREX_FORCE_PORT_SPEED = True
+ TRAFFICGEN_TREX_PORT_SPEED = 40000 # 40 gig
+
+**Note::** Setting higher than possible speeds will result in unpredictable behavior when running
+tests such as duration inaccuracy and/or complete test failure.
+
+RFC2544 Validation
+~~~~~~~~~~~~~~~~~~
+
+T-Rex can perform a verification run for a longer duration once the binary search of the
+RFC2544 trials have completed. This duration should be at least 60 seconds. This is similar
+to other traffic generator functionality where a more sustained time can be attempted to
+verify longer runs from the result of the search. This can be configured with the following
+params
+
+.. code-block:: console
+
+ TRAFFICGEN_TREX_VERIFICATION_MODE = False
+ TRAFFICGEN_TREX_VERIFICATION_DURATION = 60
+ TRAFFICGEN_TREX_MAXIMUM_VERIFICATION_TRIALS = 10
+
+The duration and maximum number of attempted verification trials can be set to change the
+behavior of this step. If the verification step fails, it will resume the binary search
+with new values where the maximum output will be the last attempted frame rate minus the
+current set thresh hold.
+
+Scapy frame definition
+~~~~~~~~~~~~~~~~~~~~~~
+
+It is possible to use a SCAPY frame definition to generate various network protocols
+by the **T-Rex** traffic generator. In case that particular network protocol layer
+is disabled by the TRAFFIC dictionary (e.g. TRAFFIC['vlan']['enabled'] = False),
+then disabled layer will be removed from the scapy format definition by VSPERF.
+
+The scapy frame definition can refer to values defined by the TRAFFIC dictionary
+by following keywords. These keywords are used in next examples.
+
+* ``Ether_src`` - refers to ``TRAFFIC['l2']['srcmac']``
+* ``Ether_dst`` - refers to ``TRAFFIC['l2']['dstmac']``
+* ``IP_proto`` - refers to ``TRAFFIC['l3']['proto']``
+* ``IP_PROTO`` - refers to upper case version of ``TRAFFIC['l3']['proto']``
+* ``IP_src`` - refers to ``TRAFFIC['l3']['srcip']``
+* ``IP_dst`` - refers to ``TRAFFIC['l3']['dstip']``
+* ``IP_PROTO_sport`` - refers to ``TRAFFIC['l4']['srcport']``
+* ``IP_PROTO_dport`` - refers to ``TRAFFIC['l4']['dstport']``
+* ``Dot1Q_prio`` - refers to ``TRAFFIC['vlan']['priority']``
+* ``Dot1Q_id`` - refers to ``TRAFFIC['vlan']['cfi']``
+* ``Dot1Q_vlan`` - refers to ``TRAFFIC['vlan']['id']``
+
+In following examples of SCAPY frame definition only relevant parts of TRAFFIC
+dictionary are shown. The rest of the TRAFFIC dictionary is set to default values
+as they are defined in ``conf/03_traffic.conf``.
+
+Please check official documentation of SCAPY project for details about SCAPY frame
+definition and supported network layers at: http://www.secdev.org/projects/scapy
+
+#. Generate ICMP frames:
+
+ .. code-block:: console
+
+ 'scapy': {
+ 'enabled': True,
+ '0' : 'Ether(src={Ether_src}, dst={Ether_dst})/IP(proto={IP_proto}, src={IP_src}, dst={IP_dst})/ICMP()',
+ '1' : 'Ether(src={Ether_dst}, dst={Ether_src})/IP(proto={IP_proto}, src={IP_dst}, dst={IP_src})/ICMP()',
+ }
+
+#. Generate IPv6 ICMP Echo Request
+
+ .. code-block:: console
+
+ 'l3' : {
+ 'srcip': 'feed::01',
+ 'dstip': 'feed::02',
+ },
+ 'scapy': {
+ 'enabled': True,
+ '0' : 'Ether(src={Ether_src}, dst={Ether_dst})/IPv6(src={IP_src}, dst={IP_dst})/ICMPv6EchoRequest()',
+ '1' : 'Ether(src={Ether_dst}, dst={Ether_src})/IPv6(src={IP_dst}, dst={IP_src})/ICMPv6EchoRequest()',
+ }
+
+#. Generate SCTP frames:
+
+ Example uses default SCAPY frame definition, which can reflect ``TRAFFIC['l3']['proto']`` settings. The same
+ approach can be used to generate other protocols, e.g. TCP.
+
+ .. code-block:: console
+
+ 'l3' : {
+ 'proto' : 'sctp',
+ },
+ 'scapy': {
+ 'enabled': True,
+ }
+