Physical media
Twisted pair: insulated metallic conductors
- Telephony and data
- Few kilometers (3-6) without repeaters/amplifiers
- Maximum data rate of < 1 MB/s
- T1: 24 channels + control channel
- Point-to-point and multi-drop with few drops
- Reasonable noise immunity at low cost
Coaxial cable: two conductors, insulated wire conductor within outer cylindrical conductor
- Common LANs, Cable TV (analog and digital)
- Few kilometers (1-5) without repeaters/amplifiers
- Data rate: from 1 MB/s to 100 MB/s
- Point-to-point or multi-point from tens to few hundred devices
- Better noise immunity at moderate cost