From d25c6ae914e128502daedfae9f611d5f75b314c9 Mon Sep 17 00:00:00 2001
From: Jet Hughes <jethughes0@gmail.com>
Date: Mon, 17 Oct 2022 11:43:05 +1300
Subject: [PATCH] vault backup: 2022-10-17 11:43:04

---
 content/notes/16-networks.md  | 32 +++++++++++++++++++++++++++++++-
 content/notes/17-app-layer.md |  9 +++++++++
 content/notes/cosc-203.md     |  2 +-
 3 files changed, 41 insertions(+), 2 deletions(-)
 create mode 100644 content/notes/17-app-layer.md

diff --git a/content/notes/16-networks.md b/content/notes/16-networks.md
index a18093121..48824f095 100644
--- a/content/notes/16-networks.md
+++ b/content/notes/16-networks.md
@@ -4,6 +4,9 @@ aliases:
 tags: 
 - cosc203
 - lecture
+sr-due: 2022-10-20
+sr-interval: 3
+sr-ease: 250
 ---
 
 # Types of devices
@@ -167,7 +170,34 @@ TCP/IP reference model
 - link
 	- transfers datagram from host to neighboring host using network layer services
 - physical
-	- 
+
+TCP/IP protocol suite
+- TCP - transmission control protocol
+- IP - internet protocol
+- ![](https://i.imgur.com/3BX3RRG.png)
+
+OSI model
+- two more layers
+	- presentation
+	- session
+- ![](https://i.imgur.com/jBhk7Ox.png)
 
 # network performance metrics
+- bandwidth - maximum rate (bits/second) a link or network can theoretically transmit
+- throughput - the actual reate a link or network is transmitting
+- ![](https://i.imgur.com/XajLKbf.png)
 
+- nodal delay - delay at a single router
+	- propagation delay - time to send data along a link
+	- transmission delay
+	- processing - time to find route within router
+	- queueing
+	- dnodal = dproc + dqueue + dtrans + dprop
+- end-to-end delay - total delay to send a packet from source to destination
+
+- packet loss
+	- queue (aka buffer) preceding link in buffer had finite capacity
+	- packet arriving to full queue dropped
+	- lost packet may be retransmitted by previous node, by source end system, or not at all
+	- also lost due to corupted packets
+	- 
diff --git a/content/notes/17-app-layer.md b/content/notes/17-app-layer.md
new file mode 100644
index 000000000..02e4c1456
--- /dev/null
+++ b/content/notes/17-app-layer.md
@@ -0,0 +1,9 @@
+---
+title: "17-app-layer"
+aliases: 
+tags: 
+- cosc203
+- lecture
+---
+
+
diff --git a/content/notes/cosc-203.md b/content/notes/cosc-203.md
index f5fb8d73d..0537fb664 100644
--- a/content/notes/cosc-203.md
+++ b/content/notes/cosc-203.md
@@ -45,7 +45,7 @@ tags:
 - [14-relational db]
 - [15-basic sql]
 - [16-networks](notes/16-networks)
-- [17-application layer]
+- [17-application layer](notes/17-app-layer)
 - [18-transport layer]
 - [19-network layer data plane]
 - [20-network layer control plane]