The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 03, 2005
Filed:
Jul. 05, 2001
Andrew Reeve, Winchester, GB;
Andrew Reeve, Winchester, GB;
Roke Manor Research Limited, Romsey, GB;
Abstract
Described herein is a method for reassembling variable length packets from fixed length cells. When a variable length packet, for example, an Internet Protocol (IP) packet, is transmitted between routers over a link which transmits data as fixed length cells, for example, an asynchronous transfer mode (ATM) link, the packet must be segmented into compatible fixed length cells. The receiving router must reassemble the original packet from the cells as they arrive. A packet buffer free pool () is provided which is maintained as a linked list, known as a 'free list', and which comprises a plurality of buffer elements (). When a first cell for a given packet arrives, a buffer element () is taken from the head of the free list and allocated to that packet. The packet data from the first and subsequent cells is copied into the allocated buffer element and each time the buffer element is moved to the end of the free list. Upon the arrival of the last cell for the given packet, the complete packet is processed. Failed reassemblies are automatically abandoned as the buffer element is reused when it reaches the head of the free list. This technique is relevant to protection against 'denial of service' attacks upon computer networks.