Types of Network Communication

Unicast

Definition: One device sends information directly to another device (one-to-one communication).
Examples: Connecting to a web server, performing a file transfer.
Usage: Common with both IPv4 and IPv6.
Limitation: Inefficient for communicating with multiple devices simultaneously (e.g., real-time streaming media).

Definition: One device sends one piece of information to all other devices on the network.
Characteristics:
- A single packet is transmitted to all devices.
- Efficient for the source device, but not scalable to the entire internet.
Scope: Limited to local IP subnet (broadcast domain).
Usage: Extensively used in IPv4 (e.g., ARP requests, routing protocol updates).
Issues: Excessive broadcasts can cause network performance problems.

Definition: Sending a single frame seen only by devices interested in receiving it (one-to-many communication).
Characteristics:
- More efficient than broadcast.
- Non-interested devices are not affected.
Usage: Common in both IPv4 and IPv6.
- IPv6 uses multicast extensively as it does not support broadcast.
- Applications include multimedia communication, stock ticker updates, and routing protocols.
Challenges: Requires careful engineering to scale in larger networks; not commonly used across the internet.

Definition: Communicate to a single device from a group of multiple devices (one-to-one-of-many communication).
Characteristics:
- Multiple devices share the same address but the closest one responds.
Usage: Common in both IPv4 and IPv6.
- Extensively used on the internet.
- Key use case is DNS (e.g., root DNS servers).
Benefit: Enables geographical distribution of servers, improving response times.

Unicast: One-to-one, inefficient for multiple recipients.
Broadcast: One-to-all, used in local networks, can cause performance issues.
Multicast: One-to-many, efficient for selective recipients, used in both IPv4 and IPv6.
Anycast: One-to-one-of-many, improves geographic distribution, commonly used in DNS.