Network
OSI Model
The OSI (Open System Interconnect) Model was developed in 1984 as an open standard to promote network interconnection and interoperability.
| Layer | Function | Examples |
|---|---|---|
| 7. Application | End User : Support for applications | HTTP, FTP, SMTP (email) |
| 6. Presentation | Syntax : Protocol conversion, structures data for the application | ASCII, JPEG, etc. |
| 5. Session | Sync & Ports : Establishes, manages and terminates sessions & connections | NFS, SQL |
| 4. Transport | End to End Connection : Is concerned with message integrity between source and destination | TCP, UDP |
| 3. Network | Packets : Combines messages into packets, adding routing information | IP, IPX |
| 2. Data Link | Frames : Handles flow control, sequencing, errors | MAC |
| 1. Physical | Cables : Provides electrical and mechanical connections to the network | cables and NIC |
MAC Addresses
Written in hexadecimal notation, composed of 12 digits, the first 6 correspond to the Organizational Uinque Identifier (OUI) and the last 6 are given by the manufacturer to each device. Every MAC address should be unique.
Large manufacturers may have many several OUI.
Fiber Optics
Glossary
- DOS : Disk Operating System
- The ancestor to Windows.
- HAL : Hardware Absraction Layer
- Used in virtualization technology.
- MAC : Media Access Control
- Unique identifier for any network device. See here.
- NAT : Network Address Translation
- Allows the translation of multiple local private addresses into a single public IP. Used in most home routers. More info
- NTFS : New Technology File System
- A file system used by Windows.
- OUI : Organizational Unique Identifier
- First part of the MAC address used to identify the manufacturer.
- SSID : Service Set Identifier
- Name used to identify it wireless networks from one another.
- WAN : Wide Area Network
- Large network not tied to a single location but spread across several locations. More info
Upcoming
- Define kernels
- Expand upond Topology (architectures)
- List IANA somewhere (assigns IP addresses to the network and ensures their unicity)
- Expand upon private IP addresses reserved (p. 50)
- Talk about firewalls and Stateful Packet Inspection
- Detail WAN/MAN/LAN
- Detail NIC & MAC
- Expand protocol / topology / deterministic
- Compare hub vs switches
- CSMA/CD
- Ethernet Frame
- Class of IP addresses
- wired vs wireless (cite 3 advantages of each)