Unit 4 Part 3 Flashcards
MAC vs. IP Addresses
MAC Address: Unique and permanent, used within a local network.
IP Address: Temporarily assigned and changes with different network connections.
Frame Check Sequence (FCS)
Purpose:
Used to detect errors in data transmission.
Extra bits/characters added to the end of frames.
Checked at the destination to ensure data integrity.
Common Algorithm:
CRC (Cyclic Redundancy Check):
Ensures that delivered data is correct.
VLAN Overview
A subnetwork grouping devices in a LAN into a new virtual LAN.
Purpose:
Enhances security by segmenting networks.
Improves performance by grouping frequently communicating devices.
Offers flexibility without needing major infrastructure changes.
VLAN Tag
A 4-byte field in an Ethernet frame.
Inserted between the source MAC address and the EtherType/length field.
Allows switches to distinguish between different VLANs.
Wireless LAN (WLAN)
Definition:
Equivalent of a wired LAN but without wires.
Can be independent or connected to existing cabled networks.
Uses:
Temporary connections, backup, and network extension.
Ideal for mobile devices, isolated areas, and places where cabling is challenging.
Wireless Access Point (WAP)
Function:
A fixed wireless transceiver broadcasting within a microcell.
Connects to a wired backbone, enabling wireless devices to access the network.
Common in public spaces like airports and hotels.
Hotspots
Definition:
Public sites offering Internet access over a WLAN.
Use Wi-Fi technology via a router or WAP connected to an ISP.
Wireless Bridge
Purpose:
Links two network segments wirelessly, avoiding the need for cables.
Usage Example:
Connecting two buildings separated by a public road.
Wi-Fi Router
Function:
Connects multiple devices to a network and the Internet.
Acts as a switch, router, and access point.
Allows both cabled and wireless devices to connect simultaneously.
Includes ports for additional connections.
Wireless Mesh Network (WMN)
Definition:
A network made up of multiple wireless nodes that communicate with each other.
Nodes spread across a large area, sharing the network connection wirelessly.
Communication:
Nodes use standard Wi-Fi protocols.
Each node acts like a router, both for devices and for other nodes.
Key Feature:
Only one node needs to be physically wired; it shares the connection wirelessly with other nodes.
Advantages of Mesh Topology
Reduced Cable Cost:
Only a few nodes need to be wired, lowering the cost of cabling.
Robustness:
If one node fails, the network can self-heal by routing through another node.
Easy to Extend:
Expanding the network is simple—just add more nodes.
Bounded vs. Unbounded Connections
Bounded (Ethernet):
Advantages:
Faster and more reliable.
Less susceptible to environmental interference.
Disadvantages:
Requires cabling, which can be less convenient.
Unbounded (Wi-Fi):
Advantages:
Easier to install and deploy.
No physical cables needed.
Disadvantages:
Susceptible to interference and higher latency.
Data must be encrypted for security.
