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:
Jul. 11, 1995
Filed:
Sep. 30, 1993
John A Harper, Golfe Juan, FR;
Digital Equipment Corporation, Maynard, MA (US);
Abstract
A digital message routing network has at least some nodes at which messages are monitored for accounting purposes. Such a node contains means for generating and compressing accounting digests, each of which consists of a key K representing the nature and route of the message and a value V associated with the message. For each message, a digest is produced in register 30, and copied into a location in a first memory 22D at a location determined by hashing its key; further digests with the same key are compressed into the digest already in that location. A second memory 23D is operated as a cyclic buffer with head and tail counters HDCT 40 and TLCT 41. The address of the head of the buffer, ie the valid area of memory 23D, is included as an index I in each digest in the first memory 22D as that digest is created. Each time a digest is created or changed in the first memory 22D, it is copied into the second memory at the location in the second memory determined by its index. Digests are read out from the second memory in blocks; the corresponding digests in the first memory thereby become invalid, and have to be restarted by initializing their values and giving them new indexes.