Electrical computers and digital processing systems: multicomput – Computer-to-computer protocol implementing – Computer-to-computer data transfer regulating
Reexamination Certificate
1999-04-13
2002-05-14
Najjar, Saleh (Department: 2159)
Electrical computers and digital processing systems: multicomput
Computer-to-computer protocol implementing
Computer-to-computer data transfer regulating
C709S225000, C709S226000, C709S229000, C709S235000, C709S238000, C709S242000
Reexamination Certificate
active
06389475
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to content-based filtering of multicast information.
2. Related Art
In a network of devices in which information is to be distributed to a large number of devices, it is known to transmit “multicast” messages, that is, messages which have multiple recipients and which are recognized by routers and routing protocols as intended to be delivered to multiple destinations. When information is to be delivered to a large number of recipients, it may be advantageous to use multicast techniques to deliver that information without incurring substantial additional overhead for administrative delivery requirements. Applications are known which use multicast techniques to deliver the same information to multiple recipients on a network, or on a network of networks such as an internet or an intranet. One known protocol, IGMP (Internet Group Management Protocol), uses a multicast address to distinguish between sets of recipients for multicast packets in an internet.
However, a problem has arisen in the art in the case when it is desired to deliver differing information to multiple recipients on a network. Because the information to be delivered is different for each recipient, or for each set of recipients in a specified interest group, there is a need to distinguish information by its content or subject matter, so that recipients which are interested in particular subjects can receive only that information of interest. However, when information is distinguished by content, the number of differing sets of information to be delivered can rapidly over-whelm any number of multicast addresses which can reasonably be reserved for differing sets of recipients.
Accordingly, it would be advantageous to provide a method and system for distributing potentially large numbers of categories of differing information to potentially large numbers of recipients with differing interests. This advantage is achieved in an embodiment of the invention in which a set of content descriptors for information are associated with a set of multicast addresses by a mapping server, and in which a set of sources and recipients associate themselves with those multicast addresses and their multicast distribution trees, so as to distribute information of interest to recipients broadly without duplication of effort and without excess use of multicast addresses.
SUMMARY OF THE INVENTION
The invention provides a method and system for content-based filtering of multicast information. A set of sources (S) which desire to distribute potentially large numbers of categories of differing information each associates a content descriptor (CD) with messages containing information in those categories, so that a set of recipients (R) can receive information in at least some of those categories. A mapping server (M) associates a multicast address (MA) and a content mask (CM) with each content descriptor, so that network elements (N), such as routers, in the network can distribute only those messages which are of interest to recipients in multicast distribution trees for those multicast addresses.
In a preferred embodiment, each source generates content descriptors for each differentiable category in a tree structured hierarchy, and obtains a multicast address and a content mask for the broadest content descriptor it is capable of distributing. Each recipient obtains the associated source, multicast address, and content mask, for each content descriptor of interest, and uses that information to join the multicast distribution tree for that information. Each network element between the source and the recipient determines what messages it must forward for further distribution in response to content descriptors, content masks, multicast addresses, and multicast distribution trees.
REFERENCES:
patent: 4979118 (1990-12-01), Shaygan
patent: 5208811 (1993-05-01), Kashio et al.
patent: 5245656 (1993-09-01), Loeb et al.
patent: 5309437 (1994-05-01), Perlman et al.
patent: 5430729 (1995-07-01), Rahnema
patent: 5477541 (1995-12-01), White et al.
patent: 5490140 (1996-02-01), Abensour et al.
patent: 5519858 (1996-05-01), Walton et al.
patent: 5530703 (1996-06-01), Liu et al.
patent: 5539734 (1996-07-01), Burwell et al.
patent: 5539737 (1996-07-01), Lo et al.
patent: 5541911 (1996-07-01), Nilakantan et al.
patent: 5546370 (1996-08-01), Ishikawa
patent: 5570366 (1996-10-01), Baker et al.
patent: 5600798 (1997-02-01), Cherukuri et al.
patent: 5631908 (1997-05-01), Saxe
patent: 5680116 (1997-10-01), Hashimoto et al.
patent: 5687324 (1997-11-01), Green et al.
patent: 5696763 (1997-12-01), Gang
patent: 5724351 (1998-03-01), Chao et al.
patent: 5754547 (1998-05-01), Nakazawa
patent: 5790554 (1998-08-01), Pitcher et al.
patent: 5802054 (1998-09-01), Bellenger
patent: 5835710 (1998-11-01), Nagami et al.
patent: 5854903 (1998-12-01), Morrison et al.
patent: 5856981 (1999-01-01), Voelker
patent: 5867799 (1999-02-01), Lang et al.
patent: 5892924 (1999-04-01), Lyon et al.
patent: 5893091 (1999-04-01), Hunt et al.
patent: 5898686 (1999-04-01), Virgile
patent: 5903559 (1999-05-01), Acharya et al.
patent: 5946316 (1999-08-01), Chen et al.
patent: 5987606 (1999-11-01), Cirasole et al.
patent: 6018766 (2000-01-01), Samuel et al.
patent: 6032194 (2000-02-01), Gai et al.
patent: 6092101 (2000-07-01), Birrell et al.
patent: 6108706 (2000-08-01), Birdwell et al.
William Stallings, Data and Computer Communications, pp: 329-333, Prentice Hall, Upper Saddle River, New Jersey 07458.
Farinacci Dino
Lin Steven
Speakman Tony
Tweedly Alex G.
Beyer Weaver & Thomas LLP
Cisco Technology Inc.
Najjar Saleh
Wolf, Esq. Dean E.
LandOfFree
Content - based filtering of multicast information does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Content - based filtering of multicast information, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Content - based filtering of multicast information will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2888525