PSTN fallback using dial on demand routing scheme
US6542499B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 9, 2001 |
| Grant date | Apr 1, 2003 |
| Priority date | — |
| Expiry date | Jul 9, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04Q2213/13389
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A call fallback scheme is provided in a packet switched network. After receiving incoming calls, a Voice over IP (VoIP) link is established over a packet switched network with a destination endpoint. VoIP packets are generated from the incoming calls and sent over the VoIP link to the destination endpoint. When a low quality of service condition is detected on the VoIP link with the destination endpoint, a fallback call is established with the destination endpoint over a circuit switched network. The VoIP packets for the incoming calls are redirected from the VoIP link to the circuit switched data link. As opposed to simply hairpinning a TDM voice call back over the PSTN network 102, the same VoIP packets for the incoming calls originally destine for the destination endpoint over the packet switched network are rerouted through the fallback call. This simplifies synchronization with VoIP packets sent over the VoIP network. Because VoIP packets for more than one call can be sent over the fallback call, the cost of maintaining the fallback call is also substantially reduced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.