- All communications are governed by protocols
- Protocols are rules that communications will follow
Network protocol requirements
Protocols must be in agreement and must include following requirements:
- Message encoding
- Message formatting and Encapsulation
- Message size
- Message delivery options (Unicast, Multicast, Broadcast, anycast)
- Message timing
Message timing includes the following -
- Flow control
- Response timeout
- Access method (deals with collisions)
Protocol suites
A group of inter-related protocols necessary to perform a communication function. The protocols are viewed in terms of layers:
- Higher layers
- Lower layers - concerned with moving data and provide services to upper layers
There are several protocol suites -
- Internet Protocol Suite (TCP/IP) - open standard
- Open Systems Interconnection (OSI)
- Apple Talk
- Novell Netware
While the OSI model is a conceptual framework for understanding network layers, TCP/IP is a specific implementation of the framework.
| OSI Layers | Protocol Suite | TCP/IP Layer |
|---|---|---|
| Application Presentation Session | HTTP, DNS, DHCP, FTP | Application |
| Transport layer | TCP, UDP | Transport layer |
| Network layer | IPv4, IPv6, ICMPv4, ICMPv6 | Internet |
| Data Link Layer Physical Layer | Ethernet, WLAN, SONET, SDH Wi-Fi | Network Access |