Networking Concepts Overview

TCP/IP Classes:
- Class A: Network numbers range from 1 to 127.
- Class B: Network numbers range from 128 to 191.
- Class C: Network numbers range from 192 to 223.
ISDN (Integrated Services Digital Network):
- BRI (Basic Rate Interface): B-channel at 64Kbps, D-channel at 16Kbps.
- PRI (Primary Rate Interface): Both B- and D-channels are 64Kbps.
802.11 Wireless Standards:
- CSMA/CA: Carrier Sense Multiple Access with Collision Avoidance, the protocol used by 802.11.
- DSSS (Direct Sequence Spread Spectrum): Used by 802.11 and exclusively by 802.11b.
- FHSS (Frequency Hopping Spread Spectrum): Another spread spectrum technology that 802.11 can use.
Network Configuration Requirements:
- To connect to the internet, a computer needs:
  - IP Address
  - Default Gateway
  - Subnet Mask
Connecting LAN Segments:
- Bridges, Switches, and Routers are used to connect multiple LAN segments.
Fast Ethernet (100Base-TX):
- Speed: 100Mbps data transmission.
- Cabling: 1 pair Cat5 UTP.
- Maximum Segment Length: 100 meters (328 feet).
Subnet Masks:
- Class A: 255.0.0.0
- Class B: 255.255.0.0
- Class C: 255.255.255.0
- Unsubnetted Netmask: Shown as /24.
DMZ (Demilitarized Zone):
- Also known as a screened subnet, used for separating a network’s public-facing services from its internal network.
Protocols:
- FTP, RLOGIN, and TELNET use TCP rather than UDP.
Attenuation:
- A decrease in signal amplitude as it propagates along a transmission medium.
SSL (Secure Sockets Layer):
- Session Key Length: Ranges from 40-bit to 256-bit.
Network Devices:
- Bridges: Operate at the data link layer to connect multiple networks.
- Routers: Operate at the network layer to connect multiple networks.
Data Backups:
- Address availability, integrity, and recovery, but not confidentiality.
IP Headers:
- IPv4: 32-bit addresses.
- IPv6: 128-bit addresses.
- Ethernet LAN: Uses 48-bit addresses for attached devices.