Update doc/faq and config comments1.0.1

Change-Id: I263f2d33ef9010d4ead0a26c390736a11edaaa20
Signed-off-by: ahothan <ahothan@cisco.com>

2 files changed, 22 insertions, 2 deletions

diff --git a/docs/development/design/ndrpdr.rst b/docs/development/design/ndrpdr.rst
index f748476..4f611a0 100644
--- a/docs/development/design/ndrpdr.rst
+++ b/docs/development/design/ndrpdr.rst
@@ -23,7 +23,12 @@ Call chain for calculating the NDR-PDR for a list of frame sizes:
 
 The search range is delimited by a left and right rate (expressed as a % of line rate per direction).
 
+The load_epsilon configuration parameter defines the accuracy of the result as a % of line rate.
+The default value of 0.1 indicates for example that the measured NDR and PDR are within 0.1% of line rate of the
+actual NDR/PDR (e.g. 0.1% of 10Gbps is 10Mbps). It also determines how small the search range must be in the binary search.
+
 The recursion narrows down the range by half and stops when:
 - the range is smaller than the configured load_epsilon value
 - or when the search hits 100% or 0% of line rate
 
+
diff --git a/docs/testing/user/userguide/faq.rst b/docs/testing/user/userguide/faq.rst
index cb5acb5..f5ff6b3 100644
--- a/docs/testing/user/userguide/faq.rst
+++ b/docs/testing/user/userguide/faq.rst
@@ -5,6 +5,8 @@
 Frequently Asked Questions
 **************************
 
+General Questions
+=================
 
 Can NFVbench be used with a different traffic generator than TRex?
 ------------------------------------------------------------------
@@ -14,15 +16,28 @@ Can I connect Trex directly to my compute node?
 -----------------------------------------------
 That is possible but you will not be able to run more advanced use cases such as PVVP inter-node which requires 2 compute nodes.
 
-
 Can I drive NFVbench using a REST interface?
 --------------------------------------------
 NFVbench can run in server mode and accept HTTP or WebSocket/SocketIO events 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
+   - of the switch port is configured as trunk (recommended method), you must enable it
+