X-Git-Url: https://gerrit.fd.io/r/gitweb?p=csit.git;a=blobdiff_plain;f=resources%2Flibraries%2Fpython%2FNATUtil.py;fp=resources%2Flibraries%2Fpython%2FNATUtil.py;h=841bd2e6836ab771f63d9944610c6dab55cd51f0;hp=ceed560a04a747d149ea183b916fc811640127a9;hb=1daa6fdc0bae284dee1b61f34534e59b60b7526a;hpb=cd417be7f836eb9346fad4f87bd4f75dc1d9a429

diff --git a/resources/libraries/python/NATUtil.py b/resources/libraries/python/NATUtil.py
index ceed560a04..841bd2e683 100644
--- a/resources/libraries/python/NATUtil.py
+++ b/resources/libraries/python/NATUtil.py
@@ -278,7 +278,7 @@ class NATUtil:
 
     @staticmethod
     def get_nat44_sessions_number(node, proto):
-        """Get number of established NAT44 sessions from NAT44 mapping data.
+        """Get number of expected NAT44 sessions from NAT44 mapping data.
 
         This keyword uses output from a CLI command,
         so it can start failing when VPP changes the output format.
@@ -287,17 +287,21 @@ class NATUtil:
         The current implementation supports both 2202 and post-2202 format.
         (The Gerrit number changing the output format is 34877.)
 
-        For TCP proto, the post-2202 format includes "timed out"
-        established sessions into its count of total sessions.
+        For TCP proto, the expected state after rampup is
+        some number of sessions in transitory state (VPP has seen the FINs),
+        and some number of sessions in established state (meaning
+        some FINs were lost in the last trial).
+        While the two states may need slightly different number of cycles
+        to process next packet, the current implementation considers
+        both of them the "fast path", so they are both counted as expected.
+
         As the tests should fail if a session is timed-out,
-        the logic substracts timed out sessions for the resturned value.
+        the logic substracts timed out sessions for the returned value
+        (only available for post-2202 format).
 
-        The 2202 output reports most of TCP sessions as in "transitory" state,
-        as opposed to "established", but the previous CSIT logic tolerated that.
-        Ideally, whis keyword would add establised and transitory sessions
-        (but without CLOSED and WAIT_CLOSED sessions) and return that.
-        The current implementation simply returns "total tcp sessions" value,
-        to preserve the previous CSIT behavior for 2202 output.
+        TODO: Investigate if it is worth to insert additional rampup trials
+        in TPUT tests to ensure all sessions are transitory before next
+        measurement.
 
         :param node: DUT node.
         :param proto: Required protocol - TCP/UDP/ICMP.
@@ -328,9 +332,7 @@ class NATUtil:
                     found = True
                 continue
             # Proto is found, find the line we are interested in.
-            if proto_l == u"tcp" and u"established" not in line:
-                continue
-            if u"total" not in line and u"established" not in line:
+            if u"total" not in line:
                 raise RuntimeError(f"show nat summary: no {proto} total.")
             # We have the line with relevant numbers.
             total_part, timed_out_part = line.split(u"(", 1)