Legacy WAN Evolution
- Dial-up 56 kbps
- ISDN 128 Kbps
- T1 1.54 Mbps
- DSL 1 Gbps possible / 100 Mbps probable
Dial-up Networking
- Leverage existing copper phone line`
- Modem used to put on the wire
- Phone unavailable for voice
- Data connection can be interrupted
- Warcraft matches dropped because someone picked the phone in the house
- Speeds vary based on line conditions
Integrated Services Digital Network (ISDN)
- Digital Circuit
- 64 Kbps channels
- Basic Rate Interface (BRI) provide 2 circuits
- Primary Rate Interface provides 23 circuits
Digital Subscriber Line (DSL)
- Many implementations
- Asymmetric Digital Subscriber Line (ADSL) most common in US
- Not the same on both sides, it means you could be downloading very fast, but your uploads could be slow.
- Data is encoded using high frequencies over existing telephone lines
- Filters are used to block data frequencies from voice handsets
- Frequencies used will vary based on line conditions
- Speeds can exceed 1 Gbps