1 Flow Control and Related Topics:

Notation

$L$ denotes the length of the frame
$R$ denotes the transmission rate
$d_{\text{trans}} = L/R$ denotes the frame transmission delay
$d_{\text{prop}}$ denotes the propagation delay
$RTT = 2 \cdot d_{\text{prop}}$ denotes the round-trip time (i.e., round-trip propagation delay)
$d_{\text{ack}}$ denotes the ACK transmission delay
$d_{\text{proc}}$ denotes the processing time
$d_{\text{total}} = d_{\text{trans}} + RTT + d_{\text{ack}} + 2 \cdot d_{\text{proc}}$
$U$ denotes the utilization rate (and is defined as $d_{\text{trans}}/d_{\text{total}}$)

Important Facts/Results

$U_\text{Stop-and-Wait} = \frac{1}{1 + \left(\frac{RTT}{d_{\text{trans}}}\right)}$

$U_\text{Fixed Window} = \frac{w}{w + \left(\frac{RTT}{d_{\text{trans}}}\right)}$

2 Graphs and Networks:

Notation

$V$ is a non-empty, finite set of vertices (or nodes)
$L$ is a finite set of unordered pairs of distinct elements of $V$ called links (or edges or arcs)
A simple graph, $G$, is an ordered pair $(V,L)$