Network Topologies, Protocols, and Architectures

Network Topologies

Ring Topology

Connects hosts in a physical ring. The last host connects to the first.

Star Topology

Connects all cables to a central point.

Extended Star Topology

Connects individual stars using hubs or switches, extending network coverage.

Hierarchical Topology

Similar to extended star, but uses a computer to control traffic instead of hubs/switches.

Mesh Topology

Provides maximum protection by connecting each host to others, ensuring service continuity.

Network Communication Methods

Broadcast

Each host sends data to all others on the network. Access is first-come, first-served (e.g., Ethernet).

Transmission Tokens

Controls access via sequential token transmission. Hosts send data when they have the token (e.g., Token Ring, FDDI).

Network Protocols

Protocols enable communication between hosts. They define rules for format, timing, sequencing, and error control. Without protocols, computers cannot interpret data streams.

Protocols govern all aspects of data communication, including:

• Physical network structure
• Data formatting for transmission
• Error handling

Network Types

LAN (Local Area Network)

Designed for limited geographical areas, offering:

• High bandwidth, multi-access media
• Private monitoring with local administration
• Continuous connectivity to local services
• Connection of physically adjacent devices

WAN (Wide Area Network)

Designed for vast geographical areas, offering:

• Access through serial interfaces at lower speeds
• Partial continuous connectivity
• Connection of devices over long distances

MAN (Metropolitan Area Network)

Covers a metropolitan area (e.g., city or suburb), often connecting multiple LANs using private lines or optical services.

SAN (Storage Area Network)

A dedicated, high-performance network for moving data between servers and storage resources. It avoids traffic conflicts and offers:

• Performance: Concurrent high-speed access for multiple servers.
• Availability: Built-in disaster tolerance with data replication over distances.
• Scalability: Supports various technologies for easy data relocation, backup, and migration.