X-Git-Url: https://git.martlubbers.net/?a=blobdiff_plain;f=a2%2F1cases.tex;h=e488ba30f53192ef4860c3d21150a12649c39927;hb=14b6a60ab5a1358f759bec66cc66fa20a4ab439a;hp=da3a34bddf405bd1a21a7d0aae2c3286656bfcf4;hpb=da69faad6643af30b9a9ed839e437ee03b0b8b47;p=tt2015.git

diff --git a/a2/1cases.tex b/a2/1cases.tex
index da3a34b..e488ba3 100644
--- a/a2/1cases.tex
+++ b/a2/1cases.tex
@@ -89,13 +89,14 @@ a feasible test suite the tests are divided into equivalence partitions. Below
 these partitions are given.
 
 \begin{enumerate}
-	\item \emph{Number of packets} in request~\footnote{A request is considered
-		establishing a connection (handshake) and a number of payload packets}
+	\item \emph{Number of segments} in request~\footnote{A request is
+		considered establishing a connection (handshake) and a number of
+		payload segments}
 		\begin{enumerate}
-			\item 0 payload packets
-			\item 1 payload packet
-			\item n=small payload packets
-			\item n=big payload packets
+			\item 0 payload segments
+			\item 1 payload segments
+			\item n=small payload segments
+			\item n=big payload segments
 		\end{enumerate}
 	\item \emph{source port}
 		\begin{enumerate}
@@ -107,18 +108,18 @@ these partitions are given.
 			\item Correct
 			\item Incorrect
 		\end{enumerate}
-	\item Bits flipped in \emph{payload}
+	\item Bit errors in \emph{payload}
 		\begin{enumerate}
 			\item Correct payload
-			\item Payload with even number of bits flipped
-			\item Payload with odd number of bits flipped
+			\item Payload with bit flips that do not show in checksum
+			\item Payload with bit flips that do show in checksum
 		\end{enumerate}
 	\item \emph{checksum}
 		\begin{enumerate}
 			\item Correct
 			\item Incorrect
 		\end{enumerate}
-	\item Packet order
+	\item \emph{Packet order}
 		\begin{enumerate}
 			\item Correct
 			\item Out of order
@@ -126,8 +127,34 @@ these partitions are given.
 		\end{enumerate}
 \end{enumerate}
 
-\textbf{hier iets over waarom deze partities relevant zijn! Waarom odd en 
-even number of bits flipped bijv interessant?}
+These partitions were chosen since they correspond to key parts of the TCP
+specification. 
+
+TCP segments are send over a TCP connection from a \emph{source} to a \emph{destination port}. Therefore segments which are received that have a 
+source or destination port set to an incorrect value should not be regarded
+as segments belonging to the connection by the SUT. 
+
+TCP uses a \emph{checksum} to catch any error introduced in headers, when this
+checksum does not match the actual computed checksum the SUT should
+disregard the received segment.
+
+The TCP checksum is also an inherently weak one, as it is simply the 
+bitwise negation of the addition, in ones complement arithmetic, 
+of all 16 bit words in the header and data of the segment (excluding the
+checksum itself). Therefore any \emph{bit error} where the ones complement value
+of one word
+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.
+
+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
+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
 
 Partitions 2 to 6 are tested using pairwise testing to keep the number of test
@@ -136,6 +163,9 @@ to do so) tested with the different request sizes of partition 1.
 
 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|}
@@ -145,15 +175,15 @@ This is expressed in Table~\ref{table:testpairs}.
 		& \# & 4 & 5 & 3 & 6 & 2 & 1a & 1b & 1c & 1d\\
 		\hline\hline
 		\multirow{9}{*}{Instance} 
-		& 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 & \doTCC & \doTCC & \doTCC & \doTCC\\
+		& 8 & b & b & b & a & b & \doTCC & \doTCC & \doTCC & \doTCC\\
+		& 9 & a & b & b & b & a & \xmark & \xmark & \doTCC & \doTCC\\
 		\hline
 \end{tabular}
 \caption{Combinations of test cases}