Transparent auto-discovery of network devices logically located between a client and server
US8725894B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 14, 2012 |
| Grant date | May 13, 2014 |
| Priority date | — |
| Expiry date | Sep 14, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L69/163
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Discovery of intermediate network devices is performed using a technique that piggybacks upon the existing standard TCP (Transport Control Protocol) “SACK” (Selective Acknowledgment) option in a SYN/ACK packet so that discovery information may be shared between pair-wise-deployed peer intermediate devices when a TCP/IP connection (Transport Control Protocol/Internet Protocol) is first established between network endpoints using a conventional three-way handshake. Use of the SACK option is combined with another technique which comprises modifying the original 16-bit value of the TCP receive window size to a special arbitrary value to mark a SYN packet as being generated by a first peer device. The marked SYN when received by the second peer device triggers that device's discovery information to be piggybacked in the SACK option of the SYN/ACK packet. The first device then piggybacks its discovery information in the SACK option of the ACK packet which completes the three-way handshake.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.