Efficient protocol for retransmit logic in reliable zero copy message transport
US6735620B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 18, 2000 |
| Grant date | May 11, 2004 |
| Priority date | — |
| Expiry date | Sep 23, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F15/17
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In a transmission protocol in which a user running an application in an address space in one data processing system wishes to transmit a data packet to another address space in another data processing system by means of direct memory access directly from a sending buffer to a receiving buffer with no copy, a mechanism is provided for minimizing the need for retransmission and for insuring proper entry into the target data processing system address space. In particular, when the first system does not receive an acknowledgment from the receiver, a special data packet with a retransmit flag bit set is sent to the second system. When this system receives the data packet with the retransmit flag bit set the second system responds either by sending a new acknowledgment or by sending a request for retransmission. No transmission back to the first system occurs, however before such a request is made and in fact the receiving system does not send this retransmission request without insuring that its receipt would be appropriate. In particular, the second system, before requesting retransmission, checks to assure that tag association is still valid so that an adapter at the second system is …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.