<p>Transport layer notes</p>
<p>Transport layer supports more of the</p>
<p>"Session layer" is mixed as "layer 5"</p>
<p>Transport and Session layer.</p>
<p>Conceptual.</p>
<p>Exist between two different layers.</p>
<h2>Problems with layer 3:</h2>
<ul>
<li>Communicate</li>
</ul>
<h2>Network connection</h2>
<p>IP cannot guarantee packet order
every packet is different unit of data
routed accross unit</p>
<p>What happens to one packet might happen different for another packet.</p>
<p>Think back to structure of ip packet.
Source and destination field.
They're all the same.
Cannot</p>
<h2>So far:</h2>
<h2>LAYER 4: TCP and UDP run on top of IP</h2>
<ul>
<li>Reliability, slower,</li>
<li>TCP is a connection oriented protocol. Connection between two devices. Bidirectional connection between devices</li>
<li>UDP is less reliable. Fast and less reliable</li>
<li>sequence number</li>
<li>acknowledgement</li>
</ul>
<h2>LAYER 3 NETWORK (IP PACKETs)</h2>
<ul>
<li>pieces of data routed from source to destination</li>
<li>[[networking-layer]]</li>
</ul>
<h2>LAYER 2: DATA Layer</h2>
<h2>LAYER 2: Physical Layer</h2>
<p>![[transport-layer 2024-12-26 15.49.35.excalidraw]]</p>
<p><img src="https://dl.dropboxusercontent.com/scl/fi/jywq5lgp6wvjrjssmz5h9/Obsidian_Do3cQh1KaN.png?rlkey=rp5ek2tykkykduvalqsqjjdau&#x26;dl=0" alt=""></p>
<p><img src="https://dl.dropboxusercontent.com/scl/fi/oht3hfc8flyerzlg5it3w/Obsidian_s6a10J1Wje.png?rlkey=84i1q1t1dpf9skzb5hp2umbgl&#x26;dl=0" alt=""></p>
<p>Segments dont have src and dst ip's. The packets provide device addressing.</p>
<p>![[transport-layer 2024-12-26 16.31.06.excalidraw]]</p>
<p><img src="https://dl.dropboxusercontent.com/scl/fi/yacoeema4rxsz3d745xpx/Obsidian_JJ07NVpgEW.png?rlkey=h11n07q8ivr3peu6rgcqh0duw&#x26;dl=0" alt=""></p>
