Exchanging synchronous data link control (SDLC) frames to adjust speed of data transfer between a client and server
US5938731A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 23, 1997 |
| Grant date | Aug 17, 1999 |
| Priority date | — |
| Expiry date | Jun 23, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L47/263
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method of automatically adjusting the line speed for communication between a client having data communications equipment (DCE) and a server having data terminal equipment (DTE). A first connection is established between the client and the server at a first speed, and the client sends a first synchronous data link control (SDLC) frame that identifies a requested speed. The server than sends a second SDLC frame in response to the first SDLC frame, identifying a second speed, wherein the second speed is the smaller of the requested speed and a predetermined (maximum) speed. If the client determines to communicate at the second speed, it drops the first connection, establishes a second connection at the second speed, and sends a third SDLC frame at the second speed; the server then sends a fourth SDLC frame in response to the third SDLC frame at the second speed, to confirm the connection, and data transmission follows. If either the client or the server does not receive an SDLC frame at the second speed within a predetermined time, it drops the second connection and establishes a third connection using the first speed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.