GitHub/quartz
1
0
Fork 2
mirror of https://github.com/jackyzha0/quartz.git synced 2025-12-27 14:54:05 -06:00
Code Issues Actions Packages Projects Releases Wiki Activity

vault backup: 2022-10-17 11:28:02

Browse Source
This commit is contained in:
Jet Hughes 2022-10-17 11:28:02 +13:00
parent 7baa8df118
commit 5722055f18
1 changed files with 57 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

60
content/notes/16-networks.md
View File

@ -108,12 +108,66 @@ Fibre-optic cable
packet switching packet switching
- host break application layer messages into packets - host break application layer messages into packets
- network fowards packets from one router to the next, across links on path from source to destination - network fowards packets from one router to the next, across links on path from source to destination
- store and foward: entire packet must arrive at trouter before it can be transmitted on next link
- packet queueing: occurs when work arrives faster than it can be serviced
store and fowards: entire packet must arrive at trouter before it can be transmitted on next link circuit switching
packet queueing: occurs when work arrives faster than it can be serviced - end-end resources allocated and reserved for "call" between source and destination
- one connection is set up - reserved resources are not shared.
- ![](https://i.imgur.com/HA7TWrq.png)
- circuit segment is idle if not used by call
- used for e.g., telephones
# network protocol # network protocol
current network structure
- ![](https://i.imgur.com/JNzSZXa.png)
- composed of multiple subnets
- a network of networks
- not owned by one entity
- you need to connect using an ISP e.g., spark vodaphone, 2degress
- have their own network
- provice access to users
- not isolated from each other
- connected using internet exchange point
- or peering link?
types of ISP
- ![](https://i.imgur.com/aGTYf13.png)
- tier 1
- potentially cover multiple countries
- content provider networks e.g., google have a private network
- often bypass tier-1, regional isps
network protocol
- a set of rules that dictate how to format, transmit and recieve data so that network devices can communicate
- like a common language for computers
- specifies a format
- what in withing the packet
- reciever can understand based on the format
- complex layered design
- explicit structure allows identification of systems pieces
- modularization eases the maintenance
- layer
- each implements a service
- via its on internal layer actions
- relying on services provided by layer below
TCP/IP reference model
- application
- exchanges message to implement a service using the services of transport layer
- transport
- transfers from one process to another using services of network layer
- encapsulates application layer message, M, with transport layer-layer header H1 to create a transport-layer segment
- Ht used by transport layer protocol to implement its service
- network
- transferse transport-layer segment from one host to another using link layer services
- link
- transfers datagram from host to neighboring host using network layer services
- physical
-
# network performance metrics # network performance metrics