Add explenation on randomisation

[tt2015.git] / a2 / 1cases.tex

diff --git a/a2/1cases.tex b/a2/1cases.tex
index 9ffc07d..69f8168 100644 (file)
--- a/a2/1cases.tex
+++ b/a2/1cases.tex
@@ -119,7 +119,7 @@ these partitions are given.
                        \item Correct
                        \item Incorrect
                \end{enumerate}
                        \item Correct
                        \item Incorrect
                \end{enumerate}

-       \item Packet order
+       \item \emph{Packet order}

                \begin{enumerate}
                        \item Correct
                        \item Out of order
                \begin{enumerate}
                        \item Correct
                        \item Out of order


@@ -147,10 +147,12 @@ increases by one, and the value of another decreases by one, is undetected.
 The SUT should exhibit the same behavior and accept packets where these type
 of bit errors occur.
 
 The SUT should exhibit the same behavior and accept packets where these type
 of bit errors occur.
 

-TCP guarantees that segments are delivered in order,even when they are received
-\emph{out of order} and that missing segments are resend. The SUT should
+TCP guarantees that segments are delivered \emph{in order}
+,even when they are received
+out of order and that missing segments are resend. The SUT should

 exhibit the same behavior. If segments are received out of order it should
 exhibit the same behavior. If segments are received out of order it should

-deliver them in order. Missing segments should be re-requested (by ACK-ing
+either reassemble them when the missing packet has arrived or request them to
+be resend when the  Missing segments should be re-requested (by ACK-ing

 the correct sequence number).  
 
 \bigskip
 the correct sequence number).  
 
 \bigskip


@@ -161,6 +163,9 @@ to do so) tested with the different request sizes of partition 1.
 
 This is expressed in Table~\ref{table:testpairs}.
 
 
 This is expressed in Table~\ref{table:testpairs}.
 

+\newcounter{TCC}
+\setcounter{TCC}{1}
+\newcommand{\doTCC}{\theTCC \stepcounter{TCC}}

 \begin{table}[H]
        \centering
        \begin{tabular}{|l|l|l|l|l|l|l|l|l|l|l|}
 \begin{table}[H]
        \centering
        \begin{tabular}{|l|l|l|l|l|l|l|l|l|l|l|}


@@ -170,15 +175,15 @@ This is expressed in Table~\ref{table:testpairs}.
                & \# & 4 & 5 & 3 & 6 & 2 & 1a & 1b & 1c & 1d\\
                \hline\hline
                \multirow{9}{*}{Instance} 
                & \# & 4 & 5 & 3 & 6 & 2 & 1a & 1b & 1c & 1d\\
                \hline\hline
                \multirow{9}{*}{Instance} 

-               & 1 & a & a & a & a & a & \checkmark & \checkmark & \checkmark & \checkmark\\
-               & 2 & a & b & b & c & b & \xmark & \xmark & \checkmark & \checkmark\\
-               & 3 & c & a & b & a & b & \xmark & \xmark & \checkmark & \checkmark\\
-               & 4 & c & b & a & c & a & \xmark & \xmark & \checkmark & \checkmark\\
-               & 5 & b & a & b & c & a & \xmark & \xmark & \checkmark & \checkmark\\
-               & 6 & b & b & a & b & b & \xmark & \xmark & \checkmark & \checkmark\\
-               & 7 & c & b & b & a & b & \checkmark & \checkmark & \checkmark & \checkmark\\
-               & 8 & b & b & b & a & b & \checkmark & \checkmark & \checkmark & \checkmark\\
-               & 9 & a & b & b & b & a & \xmark & \xmark & \checkmark & \checkmark\\
+               & 1 & a & a & a & a & a & \doTCC & \doTCC & \doTCC & \doTCC\\
+               & 2 & a & b & b & c & b & \xmark & \xmark & \doTCC & \doTCC\\
+               & 3 & c & a & b & a & b & \xmark & \xmark & \doTCC & \doTCC\\
+               & 4 & c & b & a & c & a & \xmark & \xmark & \doTCC & \doTCC\\
+               & 5 & b & a & b & c & a & \xmark & \xmark & \doTCC & \doTCC\\
+               & 6 & b & b & a & b & b & \xmark & \xmark & \doTCC & \doTCC\\
+               & 7 & c & b & b & a & b & \xmark & \doTCC & \doTCC & \doTCC\\
+               & 8 & b & b & b & a & b & \xmark & \doTCC & \doTCC & \doTCC\\
+               & 9 & a & b & b & b & a & \xmark & \xmark & \doTCC & \doTCC\\

                \hline
 \end{tabular}
 \caption{Combinations of test cases}
                \hline
 \end{tabular}
 \caption{Combinations of test cases}


@@ -209,7 +214,14 @@ test suite can be clearly assessed.
 
 As always, $100\%$ completeness is not feasible, therefore test cases are
 carefully selected to cover the most interesting parts of the TCP specification
 
 As always, $100\%$ completeness is not feasible, therefore test cases are
 carefully selected to cover the most interesting parts of the TCP specification

-to ensure a test suite.
+to ensure a complete but feasible test suite.
+
+To further increase the coverage of the test suites tests are randomized. The
+tests which test the handling of \emph{bit errors}, changes in the \emph{packet
+order} and \emph{dropped packets} randomize where they introduce an error. The
+test suite runs these tests multiple times to increase the likelihood that they
+discover a fault which is only present when an error occurs in a certain
+position. 

 
 To further decrease the number of tests needed test cases are divided into
 equivalence partitions and the combination of cases as described in 
 
 To further decrease the number of tests needed test cases are divided into
 equivalence partitions and the combination of cases as described in