Telephone Network
Originally designed for human speech (analog communications) only
POTS (Plain Old Telephone Service)
- Enables voice communications between two telephones
- Human voice (sound waves) converted to electrical signals by the sending telephone
- Signals travel through POTS and converted back to sound waves
Sending digital data over POTS
- Use modems to convert digital data to an analog format
- One modem used by sender to produce analog data
- Another modem used by receiver to regenerate digital data