Method and apparatus for determining the landing zone of a TCP packet
US7453879B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 4, 2005 |
| Grant date | Nov 18, 2008 |
| Priority date | — |
| Expiry date | Jan 18, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L69/163
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for determining whether a TCP packet lands in-zone or out-of-zone of a TCP sequence space. An anchor representing the TCP sequence number of the last TCP data byte, plus one, is updated each time a TCP data packet is received. When a new TCP packet is received, the most significant bit, bit [31], is extracted from the anchor. A two-bit value is formed by adding 1 to the extracted bit. This two-bit value is pre-pended to bits [30:0] of the anchor, as bits [32:31], to produce a 33-bit test value. Then, the sequence number of the last TCP byte of the received packet is then compared to the anchor and the test value. If the sequence number is greater than or equal to the anchor, and less than the test value, the packet lands in-zone and may be processed normally.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.