System and method for discovering path MTU of internet paths
US5959974A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 2, 1996 |
| Grant date | Sep 28, 1999 |
| Priority date | — |
| Expiry date | Dec 2, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M7/006
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A local system issues an ICMP echo request packet with a size based on an initial PMTU value corresponding to that of the local system's interface MTU. When an ICMP needfrag error packet is received by the local system, this signifies that the initial PMTU value was too large for packets of corresponding size to be transmitted through the Internet without fragmentation. The value is accordingly decreased by the local system and a next ICMP echo request packet transmitted through the Internet. The process iterates until an ICMP echo request packet is successfully transmitted through the Internet to a target system. In response thereto, the target system transmits an ICMP echo response packet back through the Internet to the local system, thereby indicating that the last-sent ICMP echo request packet from the local system had the correct PMTU value which is thereafter assumed to be the correct PMTU.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.