EP0156542A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Interconnection of communications networks
Assignee: Fujitsu Services Ltd
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Filing: 1985-03-04
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Granted: —
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Expires: 2005-03-04
Abstract
Abstract Communications networks (1,2) are interconnected by a bridge (7) which allows the stations (3,5) on each network to communicate with those on the other network. Each station has an identifying address unique in the system. Data is transmitted in the form of packets each containing a source address and a destination address. The bridge (7) includes a table (20) holding addresses of stations in the first network. Whenever the bridge receives a packet from the first network, it compares its destination address with the contents of the table, and if no match is found, transmits the packet on to the second network. The bridge also compares the source address of the packet with the contents of the table and if no match is found, enters that source address into the table. Thus, the contents of the table can be built up by the bridge by a learning process. The bridge handles transmission of packets in the opposite direction by a similar method, using a second table, holding the addresses of stations in the second network.
Inventors
- 👤 David Philip Hoare
- 👤 David John Warner
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 00:16
CPC Classifications
G; G06; G06F; G06F13/00; G06F13/38; G06F13/40; G06F13/4004; H; H04; H04L; H04L12/00; H04L12/28; H04L12/46; H04L12/4604; H04L12/462; H04L12/4625; H04L45/00; H04L45/74; H04L45/742
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
166 words
A method of transferring data from a first network (1) to a second network (2), each network comprising a plurality of stations (3,5) interconnected by transmission means (4,6), each station having an identifying address unique in the two networks, and data being transmitted in packets each defining a source address and a destination address, characterised in that the method comprises: (a) maintaining an address table (20) holding addresses exclusively of stations (3) in the first network (1), (b) comparing the destination addresses of packets transmitted over the first network with the contents of said table (20) and, if it is detected that the destination address of a packet is not held in said table, transmitting the packet on to the second network, and (c) comparing the source addresses of packets transmitted over the first network with the contents of said table and if it is detected that the source address of a packet is not held in said table, entering that source address into said table.
Claim 2
Independent Claim
166 words
A method of transferring data from a first network (1) to a second network (2), each network comprising a plurality of stations (3,5) interconnected by transmission means (4,6), each station having an identifying address unique in the two networks, and data being transmitted in packets each defining a source address and a destination address, characterised in that the method comprises: (a) maintaining an address table (20) holding addresses exclusively of stations (3) in the first network (1), (b) comparing the destination addresses of packets transmitted over the first network with the contents of said table (20) and, if it is detected that the destination address of a packet is not held in said table, transmitting the packet on to the second network, and (c) comparing the source addresses of packets transmitted over the first network with the contents of said table and if it is detected that the source address of a packet is not held in said table, entering that source address into said table.
Claim 3
Dependent Claim
131 words
Apparatus for inter- connecting first and second networks (1,2), the apparatus being arranged to receive data packets from the first network (1), each packet including a source address and a destination address, and to transfer selected ones of those packets to the second network (2), characterised by: (a) a table (20) for holding a plurality of addresses, (b) means (28) for comparing the destination address- of a packet received from the first network with the contents of said table (20) and, if no match is found, transferring that packet to the second network (2), and (c) means (27) for comparing the source address of a packet received from the first network with the contents of said table (20) and, if no match is found, entering that source address into said table.
Claim 4
Dependent Claim
131 words
Apparatus for inter- connecting first and second networks (1,2), the apparatus being arranged to receive data packets from the first network (1), each packet including a source address and a destination address, and to transfer selected ones of those packets to the second network (2), characterised by: (a) a table (20) for holding a plurality of addresses, (b) means (28) for comparing the destination address- of a packet received from the first network with the contents of said table (20) and, if no match is found, transferring that packet to the second network (2), and (c) means (27) for comparing the source address of a packet received from the first network with the contents of said table (20) and, if no match is found, entering that source address into said table.
Claim 5
Dependent Claim
20 words
Apparatus according to Claim 2 further including a buffer (22) for temporarily storing each packet received from the first network.
Claim 6
Dependent Claim
12 words
Apparatus according to Claim 3 wherein said buffer is a first-in-first-out buffer.
Claim 7
Dependent Claim
123 words
Apparatus according to any one of Claims 2-4, the apparatus also being arranged to receive data packets from the second network (2), each such packet also including a source address and a destination address, the apparatus further including: (a) a further table for holding a plurality of addresses, (b) means for comparing the destination address of a packet received from the second network (2) with the contents of said further table and, if no match is found, transferring that packet to the first network (1), and (c) means for comparing the source address of a packet received from the second network (2) with the contents of said further table and, if no match is found, entering that source address into said further table.
Claim 8
Dependent Claim
26 words
Apparatus according to Claim 5 wherein the means for comparing specified in that claim are operable simultaneously with the means for comparing specified in Claim 2.
Claim 9
Dependent Claim
54 words
Apparatus according to any one of claims 2-6 wherein each address comprises first and second portions, and wherein each said means for comparing is operative to compare the first portions of the specified addresses and to compare the second portions of the specified addresses only if the first portions are found to be equal.
Claim 10
Dependent Claim
47 words
A communications system comprising first and second networks (1,2) each network comprising a plurality of stations (3,5) interconnected by transmission means (4,6) and each station having an identifying address unique in the system, the networks being interconnected by apparatus (7) according to any one of claims 2-7.
Claim 11
Dependent Claim
48 words
A communications system comprising at least three networks (31,32,33) each network comprising as plurality of stations interconnected by transmission means and each station having an identifying address unique in the system, wherein each pair of networks is interconnected by apparatus (34,35,36) according to any one of claims 2-7.
References Cited (Backward Citations)
No citation records indexed.
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