Simple modem log-on authentication
US5440617A · kind A · utility
3Cited by
6References
27Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 11, 1994 |
| Grant date | Aug 8, 1995 |
| Priority date | — |
| Expiry date | Apr 11, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M11/06
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
After receiving an answer tone from a receiver modem, a sender modem transmits a series of DTMF pulses of predetermined tone, duration, and spacing. If the receiver modem does not verify that the pulses have the correct tone, duration and spacing, it simply hangs up.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.