Technique for connecting fax machines with advanced capabilities over a network which is not adapted to handle certain protocols
US7639403B2 · kind B2 · utility
0Cited by
6References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 14, 2005 |
| Grant date | Dec 29, 2009 |
| Priority date | — |
| Expiry date | Nov 13, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/33338
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An improved method and system for connecting Super Group 3 fax machines over network gateways that operate using the un-enhanced T.38 protocol. With the present invention, the CM tone is suppressed. Thus a gateway that generates an AnsAm tone, will not receive a CM tone in response. The T.38 protocol does not specify what occurs if a CM tone is not received; however, it has been found that, in practice, existing fax machines fall back to V.21 mode if a CM tone is not received.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.