\hypertarget{what-is-iot}{% \section{What is IoT}\label{what-is-iot}} \begin{frame}{What is IoT} \protect\hypertarget{what-is-iot-1}{} \begin{itemize} \tightlist \item Not “a computer connected to the internet” \begin{itemize} \tightlist \item Then it is really just another computer connected to the internet \end{itemize} \item Must be something else \begin{itemize} \tightlist \item It is simply devices that are resource constrained \begin{itemize} \tightlist \item Usually in more than one way \end{itemize} \end{itemize} \item Autonomous operation, the connection might not be permanent \end{itemize} \end{frame} \begin{frame}{IoT is just a concept} \protect\hypertarget{iot-is-just-a-concept}{} \begin{itemize} \tightlist \item \emph{The Internet of Things (IoT) is the network of physical devices, vehicles, home appliances and other items embedded with electronics, software, sensors, actuators, and connectivity which enables these objects to connect and exchange data.}\footnote<.->{Wikipedia “Internet of Things”} \end{itemize} \end{frame} \begin{frame}{What is an IoT Device?} \protect\hypertarget{what-is-an-iot-device}{} \begin{itemize} \tightlist \item Constrained in (one or more of): \begin{itemize} \tightlist \item Memory \item CPU \item Network bandwidth and/or latency \item Storage \end{itemize} \end{itemize} \note{What differentiates a computer from an IoT device?} \end{frame} \hypertarget{going-back-to-basics}{% \section{Going back to basics}\label{going-back-to-basics}} \begin{frame}{What is the internet again?} \protect\hypertarget{what-is-the-internet-again}{} \end{frame} \begin{frame}{OSI model} \protect\hypertarget{osi-model}{} \begin{enumerate} [1.] \tightlist \item Physical Layer \item Data Link Layer \item Network Layer \item Transport Layer \item Session Layer \item Presentation Layer \item Application Layer \end{enumerate} \begin{itemize} \tightlist \item \href{https://en.wikipedia.org/wiki/OSI_model}{Wikipedia: OSI model} \item \href{https://en.wikipedia.org/wiki/OSI_model\#Examples}{Wikipedia: OSI model\#Examples} \end{itemize} \note{Does not match the TCP/IP stack very closely.} \end{frame} \begin{frame}{Layer 1: Physical Layer} \protect\hypertarget{layer-1-physical-layer}{} \begin{itemize} \tightlist \item 10BASE5, 10BASE2 \item 10BASE-T / 100BASE-TX / 1000BASE-TX \item 802.11a/b/g/n PHY \item RS-232 \end{itemize} \note{Ethernet: Hubs and switches (that act on this level) is not on it’s own layer. It is more of a implementation detail in the architecture diagram. RS-232 signaling is used in \emph{all} MCUs, many have several ports available. It is extremely flexible, both used for implementing applications and debugging. Frequently an easy way to hack embedded devices. “USB dongles”, “USB TTL” all use RS-232 signaling. Note that this only applies to its logical signals, not voltage levels. The signaling does not specify any max data rate, very high rates (\textgreater{}= 1Mbps) is often supported.} \end{frame} \begin{frame}{Layer 2: Data Link Layer} \protect\hypertarget{layer-2-data-link-layer}{} \begin{itemize} \tightlist \item Ethernet \item WiFi \item Bluetooth \item Token Ring \end{itemize} \end{frame} \begin{frame}{Layer 3: Network Layer} \protect\hypertarget{layer-3-network-layer}{} \begin{itemize} \tightlist \item IP \item ICMP \item IPX \end{itemize} \end{frame} \begin{frame}{Layer 4: Transport Layer} \protect\hypertarget{layer-4-transport-layer}{} \begin{itemize} \tightlist \item TCP \item UDP \end{itemize} \end{frame} \begin{frame}{Layer 5: Session Layer} \protect\hypertarget{layer-5-session-layer}{} \begin{itemize} \tightlist \item “sockets” \item NetBIOS \end{itemize} \end{frame} \begin{frame}{Layer 6: Presentation Layer} \protect\hypertarget{layer-6-presentation-layer}{} \begin{itemize} \tightlist \item SSL \end{itemize} \note{This layer is not really much used in the IP stack} \end{frame} \begin{frame}{Layer 7: Application Layer} \protect\hypertarget{layer-7-application-layer}{} \begin{itemize} \tightlist \item HTTP \item MQTT \item DNS \item (everything else..) \end{itemize} \end{frame} \begin{frame}{Details: IP} \protect\hypertarget{details-ip}{} \includegraphics{images/ip-header.pdf} \note{Note that the “total length” field is 16 bits, 2 bytes, it’s maximum value is 64k, 65536.} \end{frame} \begin{frame}{Details: IP} \protect\hypertarget{details-ip-1}{} \includegraphics{images/IP-Header_eng.pdf} \end{frame} \hypertarget{notes}{% \section{Notes}\label{notes}} \begin{frame}{Assignments} \protect\hypertarget{assignments}{} \begin{itemize} \tightlist \item Measure round trip time/latency. Measure UDP, TCP. Measure when the packet size is greater than the MTU \end{itemize} \end{frame}