A packet-switched network is a communication network in which data is broken into smaller units called packets before being transmitted to its destination.
- Each packet is sent independently and may take different routes to reach the destination, where they are reassembled into the original message.
- Unlike dedicated circuits, packet-switched networks share network resources dynamically among users.
Basic Architecture of Packet-Switched Networks
Packet-switched networks are designed to send data in small packets over a shared communication medium.
- The basic architecture involves dividing the data into packets, which are independently routed through the network.
- The packets may take different paths and are reassembled into the original data at the receiving end.
Key Components of the Architecture:
- Source Node (Sender): The originator of the data, where packets are created.
- Switching Nodes (Routers/Switches): These are devices that forward the packets to the next node or destination based on the packet’s destination address.
- Destination Node (Receiver): The final recipient of the data, where packets are reassembled into the original message.
Types of Packet-Switched Services
1.) Frame Relay Services:
Frame Relay is a high-performance, wide-area network (WAN) protocol that operates at the data link layer (Layer 2) of the OSI model.
- It is designed to provide efficient, cost-effective, and high-speed data transmission across a WAN.
- Often used by businesses to connect remote offices, especially for less time-sensitive data.
Key Features:
- It uses virtual circuits to transmit data.
- The data is encapsulated in frames and sent across the network.
- Offers lower latency and higher throughput compared to older technologies like X.25.
- Provides reliable error detection, but error correction is left to the network layer.
2.) IP (Internet Protocol) Services:
IP is the principal protocol used for communication across the Internet that handles the routing and forwarding of data packets across networks, providing the necessary addressing to direct the packets to the correct destination.
- Essential for communication over the Internet and across large-scale private networks.
Key Features:
- Supports both IPv4 and IPv6 addressing.
- Involves a stateless communication model where each packet is treated independently.
- It uses hierarchical addressing (IP addresses) to route packets.
- IP works with other protocols like TCP for error detection and retransmission, enabling reliable data transfer.
3.) Ethernet Services:
Ethernet is a widely used protocol that operates at the data link layer of the OSI model for LAN communication.
- Ethernet services provide high-speed data transmission over local area networks (LANs) and can also be extended to wide area networks (WANs).
- Widely used in office environments, data centers, and campus networks for LAN connectivity.
Key Features:
- Provides connectionless communication using the CSMA/CD (Carrier Sense Multiple Access with Collision Detection) mechanism.
- Ethernet frames carry the data along with source and destination MAC (Media Access Control) addresses.
- Offers high-speed connections (1 Gbps, 10 Gbps, 100 Gbps, etc.).
- Ethernet can operate over various physical mediums, including twisted pair cables, fiber optics, and coaxial cables.