Multiplex communications – Wide area network – Packet switching
Patent
1994-02-08
1995-07-04
Safourek, Benedict V.
Multiplex communications
Wide area network
Packet switching
379113, H04J 314
Patent
active
054307090
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a method and apparatus for monitoring communication connections established over a network and in particular, but not exclusively, to the generation of call records for connections conducted in accordance with the TCP/IP protocols.
BACKGROUND ART
Entities communicating with each other over a data communications network generally do so by the exchange of data packets in accordance with a predetermined protocol. Depending on the particular protocol used, the communication service provided between the entities will generally be either connectionless or connection-oriented. A connectionless service is one in which each packet is handled in isolation from any other packet, the service having no appreciation of whether or not the packet is one of a number of packets that together form a complete message. In contrast, a connection-oriented service will establish a virtual circuit between entities that wish to communicate, in order to provide a reliable stream transport service for the packets passed between the entities, the virtual circuit being closed when the entities have finished communicating with each other; such a communication path established between entities over a virtual circuit is generally referred to as a connection whilst the communication transaction carried out from the setting up to the taking down of a connection is often referred to as a call.
It is well known to provide network monitoring equipment both for the purpose of traffic monitoring and for the purpose of fault analysis. Such monitoring equipment is mostly concerned either with analyzing individual packets or with the aggregate effect of the monitored packets as a whole (for example, for traffic estimation and network planning). U.S. patent specification No. 5,101,402 discloses a somewhat more sophisticated approach that provides for the collection of statistics on sessions conducted across connections. However, a drawback of the method disclosed in U.S. Pat. No. 5,101,402 is that it must track session protocol interactions in order to ascertain when each session terminates; as a consequence, if the passage of the relevant protocol command terminating a session is missed for any reason (such as noise or packet re-routing), an error condition will result.
It is an object of the present invention to provide a method and apparatus for monitoring calls over a network that is resilient to packet loss.
DISCLOSURE OF THE INVENTION
According to one aspect of the present invention, there is provided a method of monitoring communication connections temporarily established over a network between respective pairs of entities for passing protocol data units therebetween, each protocol data unit passed over the network being provided by the sending entity with associated connection information identifying the connection to which it relates, the method involving the steps of monitoring the network to identify said protocol data units and the connection to which each such unit relates, and maintaining an active group of call records each representing a respective said connection considered to be currently active, said maintaining step involving:
adding a new call record to said active group each time a said protocol data unit is identified as relating to a connection unrepresented in said active group;
updating an existing call record in said active group in response to any further said protocol data units being identified as relevant to the connection represented by that record; and
removing an existing said call record from said active group when said connection is judged completed having regard to a continuing absence of further protocol data units relevant to said connection.
Generally, the call records removed from the active group are retained as a completed-call group of records thereby providing a historical record of calls made. Furthermore, each call record will normally record aggregated quantitative information (for example, number of data bytes transferred) for the protocol data u
REFERENCES:
patent: 4788721 (1988-11-01), Krishnan et al.
patent: 5042027 (1991-08-01), Takase et al.
patent: 5101402 (1992-03-01), Chiu et al.
patent: 5231593 (1993-07-01), Notess
"Methods for Internet Monitoring", 10th Conference on Local Computer Networks, IEEE, New York, Oct. 7, 1985, pp. 32-40.
Hewlett--Packard Company
Safourek Benedict V.
LandOfFree
Network monitoring method and apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Network monitoring method and apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Network monitoring method and apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-765889