Determining and maintaining hop-count for switched networks
US6130889A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 1997 |
| Grant date | Oct 10, 2000 |
| Priority date | — |
| Expiry date | Sep 30, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02D30/50
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
This invention discloses a way to map IP or similar routing information onto a technology that uses label switching and swapping, such as ATM, without the need to change the network paradigm. This allows a network to continue to function and appear as a standard IP network, but with much higher performance. One of the requirements of IP networks is to decrement the IP packet Time-To-Live (TTL) field on each hop it traverses. Currently, switched packets within an ATM like network cannot decrement the TTL. This invention can decrement packet TTLs appropriately by maintaining a hop-count per each switched path. This hop-count maintains the total number of hops a packets would have traversed, had it been forwarded in the IP hop-by-hop model, rather than through the ATM like switched path. Before forwarding a packet on a switched path, an ingress ISR decrements the TTL by the hop-count. In this way, at the switched path exit point, the TTL is the same as if it had been forwarded by IP. If the decrement value is greater than or equal to the TTL of the packet, the packet may be forwarded hop-by-hop; in this situation, the packet will be discarded at the correct IP node, rather than being …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.