CSIT-1420: Split methodology section to more files

Change-Id: I861e578434abdf72244d684fca8cfd66e1db9c28
Signed-off-by: Tibor Frank <tifrank@cisco.com>

1 files changed, 18 insertions, 916 deletions

diff --git a/docs/report/introduction/methodology.rst b/docs/report/introduction/methodology.rst
index 16d3edacdb..1f9fcfe7fb 100644
--- a/docs/report/introduction/methodology.rst
+++ b/docs/report/introduction/methodology.rst
@@ -4,919 +4,21 @@
 Test Methodology
 ================
 
-VPP Forwarding Modes
---------------------
-
-VPP is tested in a number of L2 and IP packet lookup and forwarding
-modes. Within each mode baseline and scale tests are executed, the
-latter with varying number of lookup entries.
-
-L2 Ethernet Switching
-~~~~~~~~~~~~~~~~~~~~~
-
-VPP is tested in three L2 forwarding modes:
-
-- *l2patch*: L2 patch, the fastest point-to-point L2 path that loops
-  packets between two interfaces without any Ethernet frame checks or
-  lookups.
-- *l2xc*: L2 cross-connect, point-to-point L2 path with all Ethernet
-  frame checks, but no MAC learning and no MAC lookup.
-- *l2bd*: L2 bridge-domain, multipoint-to-multipoint L2 path with all
-  Ethernet frame checks, with MAC learning (unless static MACs are used)
-  and MAC lookup.
-
-l2bd tests are executed in baseline and scale configurations:
-
-- *l2bdbase*: low number of L2 flows (253 per direction) is switched by
-  VPP. They drive the content of MAC FIB size (506 total MAC entries).
-  Both source and destination MAC addresses are incremented on a packet
-  by packet basis.
-
-- *l2bdscale*: high number of L2 flows is switched by VPP. Tested MAC
-  FIB sizes include: i) 10k (5k unique flows per direction), ii) 100k
-  (2x 50k flows) and iii) 1M (2x 500k). Both source and destination MAC
-  addresses are incremented on a packet by packet basis, ensuring new
-  entries are learn refreshed and looked up at every packet, making it
-  the worst case scenario.
-
-Ethernet wire encapsulations tested include: untagged, dot1q, dot1ad.
-
-IPv4 Routing
-~~~~~~~~~~~~
-
-IPv4 routing tests are executed in baseline and scale configurations:
-
-- *ip4base*: low number of IPv4 flows (253 per direction) is routed by
-  VPP. They drive the content of IPv4 FIB size (506 total /32 prefixes).
-  Destination IPv4 addresses are incremented on a packet by packet
-  basis.
-
-- *ip4scale*: high number of IPv4 flows is routed by VPP. Tested IPv4
-  FIB sizes of /32 prefixes include: i) 20k (10k unique flows per
-  direction), ii) 200k (2x 100k flows) and iii) 2M (2x 1M). Destination
-  IPv4 addresses are incremented on a packet by packet basis, ensuring
-  new FIB entries are looked up at every packet, making it the worst
-  case scenario.
-
-IPv6 Routing
-~~~~~~~~~~~~
-
-IPv6 routing tests are executed in baseline and scale configurations:
-
-- *ip6base*: low number of IPv6 flows (253 per direction) is routed by
-  VPP. They drive the content of IPv6 FIB size (506 total /128 prefixes).
-  Destination IPv6 addresses are incremented on a packet by packet
-  basis.
-
-- *ip6scale*: high number of IPv6 flows is routed by VPP. Tested IPv6
-  FIB sizes of /128 prefixes include: i) 20k (10k unique flows per
-  direction), ii) 200k (2x 100k flows) and iii) 2M (2x 1M). Destination
-  IPv6 addresses are incremented on a packet by packet basis, ensuring
-  new FIB entries are looked up at every packet, making it the worst
-  case scenario.
-
-SRv6 Routing
-~~~~~~~~~~~~
-
-SRv6 routing tests are executed in a number of baseline configurations,
-in each case SR policy and steering policy are configured for one
-direction and one (or two) SR behaviours (functions) in the other
-directions:
-
-- *srv6enc1sid*: One SID (no SRH present), one SR function - End.
-- *srv6enc2sids*: Two SIDs (SRH present), two SR functions - End and
-  End.DX6.
-- *srv6enc2sids-nodecaps*: Two SIDs (SRH present) without decapsulation,
-  one SR function - End.
-- *srv6proxy-dyn*: Dynamic SRv6 proxy, one SR function - End.AD.
-- *srv6proxy-masq*: Masquerading SRv6 proxy, one SR function - End.AM.
-- *srv6proxy-stat*: Static SRv6 proxy, one SR function - End.AS.
-
-In all listed cases low number of IPv6 flows (253 per direction) is
-routed by VPP.
-
-Tunnel Encapsulations
----------------------
-
-Tunnel encapsulations testing is grouped based on the type of outer
-header: IPv4 or IPv6.
-
-IPv4 Tunnels
-~~~~~~~~~~~~
-
-VPP is tested in the following IPv4 tunnel baseline configurations:
-
-- *ip4vxlan-l2bdbase*: VXLAN over IPv4 tunnels with L2 bridge-domain MAC
-  switching.
-- *ip4vxlan-l2xcbase*: VXLAN over IPv4 tunnels with L2 cross-connect.
-- *ip4lispip4-ip4base*: LISP over IPv4 tunnels with IPv4 routing.
-- *ip4lispip6-ip6base*: LISP over IPv4 tunnels with IPv6 routing.
-
-In all cases listed above low number of MAC, IPv4, IPv6 flows (253 per
-direction) is switched or routed by VPP.
-
-In addition selected IPv4 tunnels are tested at scale:
-
-- *dot1q--ip4vxlanscale-l2bd*: VXLAN over IPv4 tunnels with L2 bridge-
-  domain MAC switching, with scaled up dot1q VLANs (10, 100, 1k),
-  mapped to scaled up L2 bridge-domains (10, 100, 1k), that are in turn
-  mapped to (10, 100, 1k) VXLAN tunnels. 64.5k flows are transmitted per
-  direction.
-
-IPv6 Tunnels
-~~~~~~~~~~~~
-
-VPP is tested in the following IPv6 tunnel baseline configurations:
-
-- *ip6lispip4-ip4base*: LISP over IPv4 tunnels with IPv4 routing.
-- *ip6lispip6-ip6base*: LISP over IPv4 tunnels with IPv6 routing.
-
-In all cases listed above low number of IPv4, IPv6 flows (253 per
-direction) is routed by VPP.
-
-VPP Features
-------------
-
-VPP is tested in a number of data plane feature configurations across
-different forwarding modes. Following sections list features tested.
-
-ACL Security-Groups
-~~~~~~~~~~~~~~~~~~~
-
-Both stateless and stateful access control lists (ACL), also known as
-security-groups, are supported by VPP.
-
-Following ACL configurations are tested for MAC switching with L2
-bridge-domains:
-
-- *l2bdbasemaclrn-iacl{E}sl-{F}flows*: Input stateless ACL, with {E}
-  entries and {F} flows.
-- *l2bdbasemaclrn-oacl{E}sl-{F}flows*: Output stateless ACL, with {E}
-  entries and {F} flows.
-- *l2bdbasemaclrn-iacl{E}sf-{F}flows*: Input stateful ACL, with {E}
-  entries and {F} flows.
-- *l2bdbasemaclrn-oacl{E}sf-{F}flows*: Output stateful ACL, with {E}
-  entries and {F} flows.
-
-Following ACL configurations are tested with IPv4 routing:
-
-- *ip4base-iacl{E}sl-{F}flows*: Input stateless ACL, with {E} entries
-  and {F} flows.
-- *ip4base-oacl{E}sl-{F}flows*: Output stateless ACL, with {E} entries
-  and {F} flows.
-- *ip4base-iacl{E}sf-{F}flows*: Input stateful ACL, with {E} entries and
-  {F} flows.
-- *ip4base-oacl{E}sf-{F}flows*: Output stateful ACL, with {E} entries
-  and {F} flows.
-
-ACL tests are executed with the following combinations of ACL entries
-and number of flows:
-
-- ACL entry definitions
-
-  - flow non-matching deny entry: (src-ip4, dst-ip4, src-port, dst-port).
-  - flow matching permit ACL entry: (src-ip4, dst-ip4).
-
-- {E} - number of non-matching deny ACL entries, {E} = [1, 10, 50].
-- {F} - number of UDP flows with different tuple (src-ip4, dst-ip4,
-  src-port, dst-port), {F} = [100, 10k, 100k].
-- All {E}x{F} combinations are tested per ACL type, total of 9.
-
-ACL MAC-IP
-~~~~~~~~~~
-
-MAC-IP binding ACLs are tested for MAC switching with L2 bridge-domains:
-
-- *l2bdbasemaclrn-macip-iacl{E}sl-{F}flows*: Input stateless ACL, with
-  {E} entries and {F} flows.
-
-MAC-IP ACL tests are executed with the following combinations of ACL
-entries and number of flows:
-
-- ACL entry definitions
-
-  - flow non-matching deny entry: (dst-ip4, dst-mac, bit-mask)
-  - flow matching permit ACL entry: (dst-ip4, dst-mac, bit-mask)
-
-- {E} - number of non-matching deny ACL entries, {E} = [1, 10, 50]
-- {F} - number of UDP flows with different tuple (dst-ip4, dst-mac),
-  {F} = [100, 10k, 100k]
-- All {E}x{F} combinations are tested per ACL type, total of 9.
-
-NAT44
-~~~~~
-
-NAT44 is tested in baseline and scale configurations with IPv4 routing:
-
-- *ip4base-nat44*: baseline test with single NAT entry (addr, port),
-  single UDP flow.
-- *ip4base-udpsrcscale{U}-nat44*: baseline test with {U} NAT entries
-  (addr, {U}ports), {U}=15.
-- *ip4scale{R}-udpsrcscale{U}-nat44*: scale tests with {R}*{U} NAT
-  entries ({R}addr, {U}ports), {R}=[100, 1k, 2k, 4k], {U}=15.
-
-Data Plane Throughput
----------------------
-
-Network data plane packet and bandwidth throughput are measured in
-accordance with :rfc:`2544`, using FD.io CSIT Multiple Loss Ratio search
-(MLRsearch), an optimized throughput search algorithm, that measures
-SUT/DUT packet throughput rates at different Packet Loss Ratio (PLR)
-values.
-
-Following MLRsearch values are measured across a range of L2 frame sizes
-and reported:
-
-- NON DROP RATE (NDR): packet and bandwidth throughput at PLR=0%.
-
-  - **Aggregate packet rate**: NDR_LOWER <bi-directional packet rate>
-    pps.
-  - **Aggregate bandwidth rate**: NDR_LOWER <bi-directional bandwidth
-    rate> Gbps.
-
-- PARTIAL DROP RATE (PDR): packet and bandwidth throughput at PLR=0.5%.
-
-  - **Aggregate packet rate**: PDR_LOWER <bi-directional packet rate>
-    pps.
-  - **Aggregate bandwidth rate**: PDR_LOWER <bi-directional bandwidth
-    rate> Gbps.
-
-NDR and PDR are measured for the following L2 frame sizes (untagged
-Ethernet):
-
-- IPv4 payload: 64B, IMIX (28x64B, 16x570B, 4x1518B), 1518B, 9000B.
-- IPv6 payload: 78B, IMIX (28x78B, 16x570B, 4x1518B), 1518B, 9000B.
-
-All rates are reported from external Traffic Generator perspective.
-
-.. _mlrsearch_algorithm:
-
-MLRsearch Tests
----------------
-
-Multiple Loss Rate search (MLRsearch) tests use new search algorithm
-implemented in FD.io CSIT project. MLRsearch discovers multiple packet
-throughput rates in a single search, with each rate associated with a
-distinct Packet Loss Ratio (PLR) criteria. MLRsearch is being
-standardized in IETF with `draft-vpolak-mkonstan-mlrsearch-XX
-<https://tools.ietf.org/html/draft-vpolak-mkonstan-mlrsearch-00>`_.
-
-Two throughput measurements used in FD.io CSIT are Non-Drop Rate (NDR,
-with zero packet loss, PLR=0) and Partial Drop Rate (PDR, with packet
-loss rate not greater than the configured non-zero PLR). MLRsearch
-discovers NDR and PDR in a single pass reducing required execution time
-compared to separate binary searches for NDR and PDR. MLRsearch reduces
-execution time even further by relying on shorter trial durations
-of intermediate steps, with only the final measurements
-conducted at the specified final trial duration.
-This results in the shorter overall search
-execution time when compared to a standard NDR/PDR binary search,
-while guaranteeing the same or similar results.
-
-If needed, MLRsearch can be easily adopted to discover more throughput rates
-with different pre-defined PLRs.
-
-.. Note:: All throughput rates are *always* bi-directional
-   aggregates of two equal (symmetric) uni-directional packet rates
-   received and reported by an external traffic generator.
-
-Overview
-~~~~~~~~
-
-The main properties of MLRsearch:
-
-- MLRsearch is a duration aware multi-phase multi-rate search algorithm.
-
-  - Initial phase determines promising starting interval for the search.
-  - Intermediate phases progress towards defined final search criteria.
-  - Final phase executes measurements according to the final search
-    criteria.
-
-- *Initial phase*:
-
-  - Uses link rate as a starting transmit rate and discovers the Maximum
-    Receive Rate (MRR) used as an input to the first intermediate phase.
-
-- *Intermediate phases*:
-
-  - Start with initial trial duration (in the first phase) and converge
-    geometrically towards the final trial duration (in the final phase).
-  - Track two values for NDR and two for PDR.
-
-    - The values are called (NDR or PDR) lower_bound and upper_bound.
-    - Each value comes from a specific trial measurement
-      (most recent for that transmit rate),
-      and as such the value is associated with that measurement's duration and loss.
-    - A bound can be invalid, for example if NDR lower_bound
-      has been measured with nonzero loss.
-    - Invalid bounds are not real boundaries for the searched value,
-      but are needed to track interval widths.
-    - Valid bounds are real boundaries for the searched value.
-    - Each non-initial phase ends with all bounds valid.
-
-  - Start with a large (lower_bound, upper_bound) interval width and
-    geometrically converge towards the width goal (measurement resolution)
-    of the phase. Each phase halves the previous width goal.
-  - Use internal and external searches:
-
-    - External search - measures at transmit rates outside the (lower_bound,
-      upper_bound) interval. Activated when a bound is invalid,
-      to search for a new valid bound by doubling the interval width.
-      It is a variant of `exponential search`_.
-    - Internal search - `binary search`_, measures at transmit rates within the
-      (lower_bound, upper_bound) valid interval, halving the interval width.
-
-- *Final phase* is executed with the final test trial duration, and the final
-  width goal that determines resolution of the overall search.
-  Intermediate phases together with the final phase are called non-initial phases.
-
-The main benefits of MLRsearch vs. binary search include:
-
-- In general MLRsearch is likely to execute more search trials overall, but
-  less trials at a set final duration.
-- In well behaving cases it greatly reduces (>50%) the overall duration
-  compared to a single PDR (or NDR) binary search duration,
-  while finding multiple drop rates.
-- In all cases MLRsearch yields the same or similar results to binary search.
-- Note: both binary search and MLRsearch are susceptible to reporting
-  non-repeatable results across multiple runs for very bad behaving
-  cases.
-
-Caveats:
-
-- Worst case MLRsearch can take longer than a binary search e.g. in case of
-  drastic changes in behaviour for trials at varying durations.
-
-Search Implementation
-~~~~~~~~~~~~~~~~~~~~~
-
-Following is a brief description of the current MLRsearch
-implementation in FD.io CSIT.
-
-Input Parameters
-````````````````
-
-#. *maximum_transmit_rate* - maximum packet transmit rate to be used by
-   external traffic generator, limited by either the actual Ethernet
-   link rate or traffic generator NIC model capabilities. Sample
-   defaults: 2 * 14.88 Mpps for 64B 10GE link rate,
-   2 * 18.75 Mpps for 64B 40GE NIC maximum rate.
-#. *minimum_transmit_rate* - minimum packet transmit rate to be used for
-   measurements. MLRsearch fails if lower transmit rate needs to be
-   used to meet search criteria. Default: 2 * 10 kpps (could be higher).
-#. *final_trial_duration* - required trial duration for final rate
-   measurements. Default: 30 sec.
-#. *initial_trial_duration* - trial duration for initial MLRsearch phase.
-   Default: 1 sec.
-#. *final_relative_width* - required measurement resolution expressed as
-   (lower_bound, upper_bound) interval width relative to upper_bound.
-   Default: 0.5%.
-#. *packet_loss_ratio* - maximum acceptable PLR search criteria for
-   PDR measurements. Default: 0.5%.
-#. *number_of_intermediate_phases* - number of phases between the initial
-   phase and the final phase. Impacts the overall MLRsearch duration.
-   Less phases are required for well behaving cases, more phases
-   may be needed to reduce the overall search duration for worse behaving cases.
-   Default (2). (Value chosen based on limited experimentation to date.
-   More experimentation needed to arrive to clearer guidelines.)
-
-Initial Phase
-`````````````
-
-1. First trial measures at maximum rate and discovers MRR.
-
-   a. *in*: trial_duration = initial_trial_duration.
-   b. *in*: offered_transmit_rate = maximum_transmit_rate.
-   c. *do*: single trial.
-   d. *out*: measured loss ratio.
-   e. *out*: mrr = measured receive rate.
-
-2. Second trial measures at MRR and discovers MRR2.
-
-   a. *in*: trial_duration = initial_trial_duration.
-   b. *in*: offered_transmit_rate = MRR.
-   c. *do*: single trial.
-   d. *out*: measured loss ratio.
-   e. *out*: mrr2 = measured receive rate.
-
-3. Third trial measures at MRR2.
-
-   a. *in*: trial_duration = initial_trial_duration.
-   b. *in*: offered_transmit_rate = MRR2.
-   c. *do*: single trial.
-   d. *out*: measured loss ratio.
-
-Non-initial Phases
-``````````````````
-
-1. Main loop:
-
-   a. *in*: trial_duration for the current phase.
-      Set to initial_trial_duration for the first intermediate phase;
-      to final_trial_duration for the final phase;
-      or to the element of interpolating geometric sequence
-      for other intermediate phases.
-      For example with two intermediate phases, trial_duration
-      of the second intermediate phase is the geometric average
-      of initial_strial_duration and final_trial_duration.
-   b. *in*: relative_width_goal for the current phase.
-      Set to final_relative_width for the final phase;
-      doubled for each preceding phase.
-      For example with two intermediate phases,
-      the first intermediate phase uses quadruple of final_relative_width
-      and the second intermediate phase uses double of final_relative_width.
-   c. *in*: ndr_interval, pdr_interval from the previous main loop iteration
-      or the previous phase.
-      If the previous phase is the initial phase, both intervals have
-      lower_bound = MRR2, uper_bound = MRR.
-      Note that the initial phase is likely to create intervals with invalid bounds.
-   d. *do*: According to the procedure described in point 2,
-      either exit the phase (by jumping to 1.g.),
-      or prepare new transmit rate to measure with.
-   e. *do*: Perform the trial measurement at the new transmit rate
-      and trial_duration, compute its loss ratio.
-   f. *do*: Update the bounds of both intervals, based on the new measurement.
-      The actual update rules are numerous, as NDR external search
-      can affect PDR interval and vice versa, but the result
-      agrees with rules of both internal and external search.
-      For example, any new measurement below an invalid lower_bound
-      becomes the new lower_bound, while the old measurement
-      (previously acting as the invalid lower_bound)
-      becomes a new and valid upper_bound.
-      Go to next iteration (1.c.), taking the updated intervals as new input.
-   g. *out*: current ndr_interval and pdr_interval.
-      In the final phase this is also considered
-      to be the result of the whole search.
-      For other phases, the next phase loop is started
-      with the current results as an input.
-
-2. New transmit rate (or exit) calculation (for 1.d.):
-
-   - If there is an invalid bound then prepare for external search:
-
-     - *If* the most recent measurement at NDR lower_bound transmit rate
-       had the loss higher than zero, then
-       the new transmit rate is NDR lower_bound
-       decreased by two NDR interval widths.
-     - Else, *if* the most recent measurement at PDR lower_bound
-       transmit rate had the loss higher than PLR, then
-       the new transmit rate is PDR lower_bound
-       decreased by two PDR interval widths.
-     - Else, *if* the most recent measurement at NDR upper_bound
-       transmit rate had no loss, then
-       the new transmit rate is NDR upper_bound
-       increased by two NDR interval widths.
-     - Else, *if* the most recent measurement at PDR upper_bound
-       transmit rate had the loss lower or equal to PLR, then
-       the new transmit rate is PDR upper_bound
-       increased by two PDR interval widths.
-   - If interval width is higher than the current phase goal:
-
-     - Else, *if* NDR interval does not meet the current phase width goal,
-       prepare for internal search. The new transmit rate is
-       (NDR lower bound + NDR upper bound) / 2.
-     - Else, *if* PDR interval does not meet the current phase width goal,
-       prepare for internal search. The new transmit rate is
-       (PDR lower bound + PDR upper bound) / 2.
-   - Else, *if* some bound has still only been measured at a lower duration,
-     prepare to re-measure at the current duration (and the same transmit rate).
-     The order of priorities is:
-
-     - NDR lower_bound,
-     - PDR lower_bound,
-     - NDR upper_bound,
-     - PDR upper_bound.
-   - *Else*, do not prepare any new rate, to exit the phase.
-     This ensures that at the end of each non-initial phase
-     all intervals are valid, narrow enough, and measured
-     at current phase trial duration.
-
-Implementation Deviations
-~~~~~~~~~~~~~~~~~~~~~~~~~
-
-This document so far has been describing a simplified version of MLRsearch algorithm.
-The full algorithm as implemented contains additional logic,
-which makes some of the details (but not general ideas) above incorrect.
-Here is a short description of the additional logic as a list of principles,
-explaining their main differences from (or additions to) the simplified description,
-but without detailing their mutual interaction.
-
-1. *Logarithmic transmit rate.*
-   In order to better fit the relative width goal,
-   the interval doubling and halving is done differently.
-   For example, the middle of 2 and 8 is 4, not 5.
-2. *Optimistic maximum rate.*
-   The increased rate is never higher than the maximum rate.
-   Upper bound at that rate is always considered valid.
-3. *Pessimistic minimum rate.*
-   The decreased rate is never lower than the minimum rate.
-   If a lower bound at that rate is invalid,
-   a phase stops refining the interval further (until it gets re-measured).
-4. *Conservative interval updates.*
-   Measurements above current upper bound never update a valid upper bound,
-   even if drop ratio is low.
-   Measurements below current lower bound always update any lower bound
-   if drop ratio is high.
-5. *Ensure sufficient interval width.*
-   Narrow intervals make external search take more time to find a valid bound.
-   If the new transmit increased or decreased rate would result in width
-   less than the current goal, increase/decrease more.
-   This can happen if the measurement for the other interval
-   makes the current interval too narrow.
-   Similarly, take care the measurements in the initial phase
-   create wide enough interval.
-6. *Timeout for bad cases.*
-   The worst case for MLRsearch is when each phase converges to intervals
-   way different than the results of the previous phase.
-   Rather than suffer total search time several times larger
-   than pure binary search, the implemented tests fail themselves
-   when the search takes too long (given by argument *timeout*).
-
-(B)MRR Throughput
------------------
-
-Maximum Receive Rate (MRR) tests are complementary to MLRsearch tests,
-as they provide a maximum "raw" throughput benchmark for development and
-testing community. MRR tests measure the packet forwarding rate under
-the maximum load offered by traffic generator over a set trial duration,
-regardless of packet loss. Maximum load for specified Ethernet frame
-size is set to the bi-directional link rate.
-
-In |csit-release| MRR test code has been updated with a configurable
-burst MRR parameters: trial duration and number of trials in a single
-burst. This enabled a new Burst MRR (BMRR) methodology for more precise
-performance trending.
-
-Current parameters for BMRR tests:
-
-- Ethernet frame sizes: 64B (78B for IPv6), IMIX, 1518B, 9000B; all
-  quoted sizes include frame CRC, but exclude per frame transmission
-  overhead of 20B (preamble, inter frame gap).
-
-- Maximum load offered: 10GE and 40GE link (sub-)rates depending on NIC
-  tested, with the actual packet rate depending on frame size,
-  transmission overhead and traffic generator NIC forwarding capacity.
-
-  - For 10GE NICs the maximum packet rate load is 2* 14.88 Mpps for 64B,
-    a 10GE bi-directional link rate.
-  - For 25GE NICs the maximum packet rate load is 2* 18.75 Mpps for 64B,
-    a 25GE bi-directional link sub-rate limited by TG 25GE NIC used,
-    XXV710.
-  - For 40GE NICs the maximum packet rate load is 2* 18.75 Mpps for 64B,
-    a 40GE bi-directional link sub-rate limited by TG 40GE NIC used,
-    XL710. Packet rate for other tested frame sizes is limited by PCIe
-    Gen3 x8 bandwidth limitation of ~50Gbps.
-
-- Trial duration: 1 sec.
-
-- Number of trials per burst: 10.
-
-Similarly to NDR/PDR throughput tests, MRR test should be reporting bi-
-directional link rate (or NIC rate, if lower) if tested VPP
-configuration can handle the packet rate higher than bi-directional link
-rate, e.g. large packet tests and/or multi-core tests.
-
-MRR tests are currently used for FD.io CSIT continuous performance
-trending and for comparison between releases. Daily trending job tests
-subset of frame sizes, focusing on 64B (78B for IPv6) for all tests and
-IMIX for selected tests (vhost, memif).
-
-MRR-like measurements are being used to establish starting conditions
-for experimental Probabilistic Loss Ratio Search (PLRsearch) used for
-soak testing, aimed at verifying continuous system performance over an
-extended period of time, hours, days, weeks, months. PLRsearch code is
-currently in experimental phase in FD.io CSIT project.
-
-Packet Latency
---------------
-
-TRex Traffic Generator (TG) is used for measuring latency of VPP DUTs.
-Reported latency values are measured using following methodology:
-
-- Latency tests are performed at 100% of discovered NDR and PDR rates
-  for each throughput test and packet size (except IMIX).
-- TG sends dedicated latency streams, one per direction, each at the
-  rate of 9 kpps at the prescribed packet size; these are sent in
-  addition to the main load streams.
-- TG reports min/avg/max latency values per stream direction, hence two
-  sets of latency values are reported per test case; future release of
-  TRex is expected to report latency percentiles.
-- Reported latency values are aggregate across two SUTs due to three
-  node topology used for all performance tests; for per SUT latency,
-  reported value should be divided by two.
-- 1usec is the measurement accuracy advertised by TRex TG for the setup
-  used in FD.io labs used by CSIT project.
-- TRex setup introduces an always-on error of about 2*2usec per latency
-  flow additonal Tx/Rx interface latency induced by TRex SW writing and
-  reading packet timestamps on CPU cores without HW acceleration on NICs
-  closer to the interface line.
-
-Multi-Core Speedup
-------------------
-
-All performance tests are executed with single processor core and with
-multiple cores scenarios.
-
-Intel Hyper-Threading (HT)
-~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-Intel Xeon processors used in FD.io CSIT can operate either in HT
-Disabled mode (single logical core per each physical core) or in HT
-Enabled mode (two logical cores per each physical core). HT setting is
-applied in BIOS and requires server SUT reload for it to take effect,
-making it impractical for continuous changes of HT mode of operation.
-
-|csit-release| performance tests are executed with server SUTs' Intel
-XEON processors configured with Intel Hyper-Threading Disabled for all
-Xeon Haswell testbeds (3n-hsw) and with Intel Hyper-Threading Enabled
-for all Xeon Skylake testbeds.
-
-More information about physical testbeds is provided in
-:ref:`tested_physical_topologies`.
-
-Multi-core Tests
-~~~~~~~~~~~~~~~~
-
-|csit-release| multi-core tests are executed in the following VPP worker
-thread and physical core configurations:
-
-#. Intel Xeon Haswell testbeds (3n-hsw) with Intel HT disabled
-   (1 logical CPU core per each physical core):
-
-  #. 1t1c - 1 VPP worker thread on 1 physical core.
-  #. 2t2c - 2 VPP worker threads on 2 physical cores.
-  #. 4t4c - 4 VPP worker threads on 4 physical cores.
-
-#. Intel Xeon Skylake testbeds (2n-skx, 3n-skx) with Intel HT enabled
-   (2 logical CPU cores per each physical core):
-
-  #. 2t1c - 2 VPP worker threads on 1 physical core.
-  #. 4t2c - 4 VPP worker threads on 2 physical cores.
-  #. 8t4c - 8 VPP worker threads on 4 physical cores.
-
-VPP worker threads are the data plane threads running on isolated
-logical cores. With Intel HT enabled VPP workers are placed as sibling
-threads on each used physical core. VPP control threads (main, stats)
-are running on a separate non-isolated core together with other Linux
-processes.
-
-In all CSIT tests care is taken to ensure that each VPP worker handles
-the same amount of received packet load and does the same amount of
-packet processing work. This is achieved by evenly distributing per
-interface type (e.g. physical, virtual) receive queues over VPP workers
-using default VPP round- robin mapping and by loading these queues with
-the same amount of packet flows.
-
-If number of VPP workers is higher than number of physical or virtual
-interfaces, multiple receive queues are configured on each interface.
-NIC Receive Side Scaling (RSS) for physical interfaces and multi-queue
-for virtual interfaces are used for this purpose.
-
-Section :ref:`throughput_speedup_multi_core` includes a set of graphs
-illustrating packet throughout speedup when running VPP worker threads
-on multiple cores. Note that in quite a few test cases running VPP
-workers on 2 or 4 physical cores hits the I/O bandwidth or packets-per-
-second limit of tested NIC.
-
-VPP Startup Settings
---------------------
-
-CSIT code manipulates a number of VPP settings in startup.conf for optimized
-performance. List of common settings applied to all tests and test
-dependent settings follows.
-
-See `VPP startup.conf <https://git.fd.io/vpp/tree/src/vpp/conf/startup.conf?h=stable/1807>`_
-for a complete set and description of listed settings.
-
-Common Settings
-~~~~~~~~~~~~~~~
-
-List of vpp startup.conf settings applied to all tests:
-
-#. heap-size <value> - set separately for ip4, ip6, stats, main
-   depending on scale tested.
-#. no-tx-checksum-offload - disables UDP / TCP TX checksum offload in DPDK.
-   Typically needed for use faster vector PMDs (together with
-   no-multi-seg).
-#. socket-mem <value>,<value> - memory per numa. (Not required anymore
-   due to VPP code changes, should be removed in CSIT-18.10.)
-
-Per Test Settings
-~~~~~~~~~~~~~~~~~
-
-List of vpp startup.conf settings applied dynamically per test:
-
-#. corelist-workers <list_of_cores> - list of logical cores to run VPP
-   worker data plane threads. Depends on HyperThreading and core per
-   test configuration.
-#. num-rx-queues <value> - depends on a number of VPP threads and NIC
-   interfaces.
-#. num-rx-desc/num-tx-desc - number of rx/tx descriptors for specific
-   NICs, incl. xl710, x710, xxv710.
-#. num-mbufs <value> - increases number of buffers allocated, needed
-   only in scenarios with large number of interfaces and worker threads.
-   Value is per CPU socket. Default is 16384.
-#. no-multi-seg - disables multi-segment buffers in DPDK, improves
-   packet throughput, but disables Jumbo MTU support. Disabled for all
-   tests apart from the ones that require Jumbo 9000B frame support.
-#. UIO driver - depends on topology file definition.
-#. QAT VFs - depends on NRThreads, each thread = 1QAT VFs.
-
-KVM VMs vhost-user
-------------------
-
-FD.io CSIT performance lab is testing VPP vhost with KVM VMs using
-following environment settings:
-
-- Tests with varying Qemu virtio queue (a.k.a. vring) sizes: [vr256]
-  default 256 descriptors, [vr1024] 1024 descriptors to optimize for
-  packet throughput.
-- Tests with varying Linux :abbr:`CFS (Completely Fair Scheduler)`
-  settings: [cfs] default settings, [cfsrr1] CFS RoundRobin(1) policy
-  applied to all data plane threads handling test packet path including
-  all VPP worker threads and all Qemu testpmd poll-mode threads.
-- Resulting test cases are all combinations with [vr256,vr1024] and
-  [cfs,cfsrr1] settings.
-- Adjusted Linux kernel :abbr:`CFS (Completely Fair Scheduler)`
-  scheduler policy for data plane threads used in CSIT is documented in
-  `CSIT Performance Environment Tuning wiki
-  <https://wiki.fd.io/view/CSIT/csit-perf-env-tuning-ubuntu1604>`_.
-- The purpose is to verify performance impact (MRR and NDR/PDR
-  throughput) and same test measurements repeatability, by making VPP
-  and VM data plane threads less susceptible to other Linux OS system
-  tasks hijacking CPU cores running those data plane threads.
-
-LXC/DRC Container Memif
------------------------
-
-|csit-release| includes tests taking advantage of VPP memif virtual
-interface (shared memory interface) to interconnect VPP running in
-Containers. VPP vswitch instance runs in bare-metal user-mode handling
-NIC interfaces and connecting over memif (Slave side) to VPPs running in
-:abbr:`Linux Container (LXC)` or in Docker Container (DRC) configured
-with memif (Master side). LXCs and DRCs run in a priviliged mode with
-VPP data plane worker threads pinned to dedicated physical CPU cores per
-usual CSIT practice. All VPP instances run the same version of software.
-This test topology is equivalent to existing tests with vhost-user and
-VMs as described earlier in :ref:`tested_logical_topologies`.
-
-In addition to above vswitch tests, a single memif interface test is
-executed. It runs in a simple topology of two VPP container instances
-connected over memif interface in order to verify standalone memif
-interface performance.
-
-More information about CSIT LXC and DRC setup and control is available
-in :ref:`container_orchestration_in_csit`.
-
-K8s Container Memif
--------------------
-
-|csit-release| includes tests of VPP topologies running in K8s
-orchestrated Pods/Containers and connected over memif virtual
-interfaces. In order to provide simple topology coding flexibility and
-extensibility container orchestration is done with `Kubernetes
-<https://github.com/kubernetes>`_ using `Docker
-<https://github.com/docker>`_ images for all container applications
-including VPP. `Ligato <https://github.com/ligato>`_ is used for the
-Pod/Container networking orchestration that is integrated with K8s,
-including memif support.
-
-In these tests VPP vswitch runs in a K8s Pod with Docker Container (DRC)
-handling NIC interfaces and connecting over memif to more instances of
-VPP running in Pods/DRCs. All DRCs run in a priviliged mode with VPP
-data plane worker threads pinned to dedicated physical CPU cores per
-usual CSIT practice. All VPP instances run the same version of software.
-This test topology is equivalent to existing tests with vhost-user and
-VMs as described earlier in :ref:`tested_physical_topologies`.
-
-Further documentation is available in
-:ref:`container_orchestration_in_csit`.
-
-VPP_Device Functional
----------------------
-
-|csit-release| added new VPP_Device test environment for functional VPP
-device tests integrated into LFN CI/CD infrastructure. VPP_Device tests
-run on 1-Node testbeds (1n-skx, 1n-arm) and rely on Linux SRIOV Virtual
-Function (VF), dot1q VLAN tagging and external loopback cables to
-facilitate packet passing over exernal physical links. Initial focus is
-on few baseline tests. Existing CSIT VIRL tests can be moved to
-VPP_Device framework by changing L1 and L2 KW(s). RF test definition
-code stays unchanged with the exception of requiring adjustments from
-3-Node to 2-Node logical topologies. CSIT VIRL to VPP_Device migration
-is expected in the next CSIT release.
-
-IPSec on Intel QAT
-------------------
-
-VPP IPSec performance tests are using DPDK cryptodev device driver in
-combination with HW cryptodev devices - Intel QAT 8950 50G - present in
-LF FD.io physical testbeds. DPDK cryptodev can be used for all IPSec
-data plane functions supported by VPP.
-
-Currently |csit-release| implements following IPSec test cases:
-
-- AES-GCM, CBC-SHA1 ciphers, in combination with IPv4 routed-forwarding
-  with Intel xl710 NIC.
-- CBC-SHA1 ciphers, in combination with LISP-GPE overlay tunneling for
-  IPv4-over-IPv4 with Intel xl710 NIC.
-
-TRex Traffic Generator
-----------------------
-
-Usage
-~~~~~
-
-`TRex traffic generator <https://wiki.fd.io/view/TRex>`_ is used for all
-CSIT performance tests. TRex stateless mode is used to measure NDR and
-PDR throughputs using binary search (NDR and PDR discovery tests) and
-for quick checks of DUT performance against the reference NDRs (NDR
-check tests) for specific configuration.
-
-TRex is installed and run on the TG compute node. The typical procedure
-is:
-
-- If the TRex is not already installed on TG, it is installed in the
-  suite setup phase - see `TRex intallation`_.
-- TRex configuration is set in its configuration file
-  ::
-
-  /etc/trex_cfg.yaml
-
-- TRex is started in the background mode
-  ::
-
-  $ sh -c 'cd <t-rex-install-dir>/scripts/ && sudo nohup ./t-rex-64 -i -c 7 --iom 0 > /tmp/trex.log 2>&1 &' > /dev/null
-
-- There are traffic streams dynamically prepared for each test, based on traffic
-  profiles. The traffic is sent and the statistics obtained using
-  :command:`trex_stl_lib.api.STLClient`.
-
-Measuring Packet Loss
-~~~~~~~~~~~~~~~~~~~~~
-
-Following sequence is followed to measure packet loss:
-
-- Create an instance of STLClient.
-- Connect to the client.
-- Add all streams.
-- Clear statistics.
-- Send the traffic for defined time.
-- Get the statistics.
-
-If there is a warm-up phase required, the traffic is sent also before
-test and the statistics are ignored.
-
-Measuring Latency
-~~~~~~~~~~~~~~~~~
-
-If measurement of latency is requested, two more packet streams are
-created (one for each direction) with TRex flow_stats parameter set to
-STLFlowLatencyStats. In that case, returned statistics will also include
-min/avg/max latency values.
-
-HTTP/TCP with WRK Tool
-----------------------
-
-`WRK HTTP benchmarking tool <https://github.com/wg/wrk>`_ is used for
-experimental TCP/IP and HTTP tests of VPP TCP/IP stack and built-in
-static HTTP server. WRK has been chosen as it is capable of generating
-significant TCP/IP and HTTP loads by scaling number of threads across
-multi-core processors.
-
-This in turn enables quite high scale benchmarking of the main TCP/IP
-and HTTP service including HTTP TCP/IP Connections-Per-Second (CPS),
-HTTP Requests-Per-Second and HTTP Bandwidth Throughput.
-
-The initial tests are designed as follows:
-
-- HTTP and TCP/IP Connections-Per-Second (CPS)
-
-  - WRK configured to use 8 threads across 8 cores, 1 thread per core.
-  - Maximum of 50 concurrent connections across all WRK threads.
-  - Timeout for server responses set to 5 seconds.
-  - Test duration is 30 seconds.
-  - Expected HTTP test sequence:
-
-    - Single HTTP GET Request sent per open connection.
-    - Connection close after valid HTTP reply.
-    - Resulting flow sequence - 8 packets: >Syn, <Syn-Ack, >Ack, >Req,
-      <Rep, >Fin, <Fin, >Ack.
-
-- HTTP Requests-Per-Second
-
-  - WRK configured to use 8 threads across 8 cores, 1 thread per core.
-  - Maximum of 50 concurrent connections across all WRK threads.
-  - Timeout for server responses set to 5 seconds.
-  - Test duration is 30 seconds.
-  - Expected HTTP test sequence:
-
-    - Multiple HTTP GET Requests sent in sequence per open connection.
-    - Connection close after set test duration time.
-    - Resulting flow sequence: >Syn, <Syn-Ack, >Ack, >Req[1], <Rep[1],
-      .., >Req[n], <Rep[n], >Fin, <Fin, >Ack.
-
-.. _binary search: https://en.wikipedia.org/wiki/Binary_search
-.. _exponential search: https://en.wikipedia.org/wiki/Exponential_search
-.. _estimation of standard deviation: https://en.wikipedia.org/wiki/Unbiased_estimation_of_standard_deviation
-.. _simplified error propagation formula: https://en.wikipedia.org/wiki/Propagation_of_uncertainty#Simplification
+.. toctree::
+
+    methodology_vpp_forwarding_modes
+    methodology_tunnel_encapsulations
+    methodology_vpp_features
+    methodology_data_plane_throughput
+    methodology_mlrsearch_tests
+    methodology_bmrr_throughput
+    methodology_packet_latency
+    methodology_multi_core_speedup
+    methodology_vpp_startup_settings
+    methodology_kvm_vms_vhost_user
+    methodology_lxc_drc_container_memif
+    methodology_k8s_container_memif
+    methodology_vpp_device_functional
+    methodology_ipsec_on_intel_qat
+    methodology_trex_traffic_generator
+    methodology_http_tcp_with_wrk_tool