Connected: An Internet Encyclopedia
2.2.2 Networks
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2. INTERNET ARCHITECTURE
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2.2 Elements of the Architecture
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2.2.2 Networks
2.2.2 Networks
The constituent networks of the Internet system are required to
provide only packet (connectionless) transport. According to the IP
service specification, datagrams can be delivered out of order, be
lost or duplicated, and/or contain errors.
For reasonable performance of the protocols that use IP (e.g., TCP),
the loss rate of the network should be very low. In networks
providing connection-oriented service, the extra reliability provided
by virtual circuits enhances the end-end robustness of the system,
but is not necessary for Internet operation.
Constituent networks may generally be divided into two classes:
- Local-Area Networks (LANs)
LANs may have a variety of designs. LANs normally cover a small
geographical area (e.g., a single building or plant site) and
provide high bandwidth with low delays. LANs may be passive
(similar to Ethernet) or they may be active (such as ATM).
- Wide-Area Networks (WANs)
Geographically dispersed hosts and LANs are interconnected by
wide-area networks, also called long-haul networks. These
networks may have a complex internal structure of lines and
packet-switches, or they may be as simple as point-to-point
lines.
Next: 2.2.3 Routers
Connected: An Internet Encyclopedia
2.2.2 Networks