EP0281785A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Bridge system for connecting networks
Assignee: Hughes Lan Systems Inc
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Filing: 1988-02-12
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Granted: —
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Expires: 2008-02-12
Abstract
Abstract A large number of local area networks (52, 58) are each connected to a backbone network (80) through a network interface module (NIM) (82-88). The NIM transmits messages from one local area network to another local area network across the backbone network by enveloping the local area network message inside the data field of a backbone network message. Each of the NIM constructs a table of addresses. The backbone network messages are each addressed to the particular destination NIM. The destination NIM receives the backbone network message and de-envelopes it for transmission over its own local area network.
Inventors
- 👤 Amatzia, (Nmi) Ben-Artzi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 12:08
CPC Classifications
H; H04; H04L; H04L12/00; H04L12/28; H04L12/46; H04L12/4604; H04L12/4616; H04L45/00; H04L45/74; H04L45/742; H04L2212/00
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
270 words
A network interface module (NIM) for connecting a local area network to a backbone network comprising: a first interface co-processor connected to a local area network for transmitting and receiving local area network messages to and from said local area network; a second interface co-processor connected to a backbone network for transmitting and receiving backbone network messages to and from said backbone network; a memory means connected to said first and second interface co-processor for storing a bridge identification address, a table of addresses, and for temporarily storing said local area network and backbone network messages; and a logic means connected to the first and second interface co-processors and the memory means for storing information from a source address in said local area network message in said table of addresses, comparing a destination address in said local area network with said table of addresses, and if the destination address is associated with the bridge identification address, then ignoring said local area network message, and if the destination address is associated with the bridge identification address of a second NIM, then enveloping said local area network message in a backbone network message addressed to said second NIM, and if the destination address is not associated with any of the addresses in said address table, then enveloping said local area network message in a backbone network message addressed to be multicast to all other NIMs on said backbone network, the logic means is further used for storing source address information in said backbone message in said table of addresses, and de-enveloping said backbone network message for transmission to said local area network.
Claim 2
Dependent Claim
270 words
A network interface module (NIM) for connecting a local area network to a backbone network comprising: a first interface co-processor connected to a local area network for transmitting and receiving local area network messages to and from said local area network; a second interface co-processor connected to a backbone network for transmitting and receiving backbone network messages to and from said backbone network; a memory means connected to said first and second interface co-processor for storing a bridge identification address, a table of addresses, and for temporarily storing said local area network and backbone network messages; and a logic means connected to the first and second interface co-processors and the memory means for storing information from a source address in said local area network message in said table of addresses, comparing a destination address in said local area network with said table of addresses, and if the destination address is associated with the bridge identification address, then ignoring said local area network message, and if the destination address is associated with the bridge identification address of a second NIM, then enveloping said local area network message in a backbone network message addressed to said second NIM, and if the destination address is not associated with any of the addresses in said address table, then enveloping said local area network message in a backbone network message addressed to be multicast to all other NIMs on said backbone network, the logic means is further used for storing source address information in said backbone message in said table of addresses, and de-enveloping said backbone network message for transmission to said local area network.
Claim 3
Dependent Claim
65 words
The device of claim 1 wherein, the logic means envelopes a local area network message into a backbone network message by putting the local area network message into the data field of a backbone message, adding a destination address comprised of either a NIM identification address or a multicast address, and adding a source address comprised of said NIM identification address of the particular NIM.
Claim 4
Dependent Claim
39 words
The device of claim 2 wherein, the logic means further envelopes a local area network message in a backbone network message by calculating a backbone frame check sequence and adding it after said data field of said backbone message.
Claim 5
Dependent Claim
63 words
The device of claim 3 wherein, the logic means de-envelopes a backbone message by using the backbone frame check sequence to verify the accuracy of said backbone message and if it is a valid message, then the logic means takes the entire data frame of the backbone message and passes it to the first interface co-processor for transmission to the local area network.
Claim 6
Dependent Claim
14 words
The device of claim 1 wherein, the local area network is an ethernet network.
Claim 7
Dependent Claim
14 words
The device of claim 1 wherein, the backbone network is a token bus network.
Claim 8
Dependent Claim
22 words
The device of claim 1 wherein, the memory means is comprised of a dynamic RAM, an identification EEPROM and a non-volatile RAM.
Claim 9
Dependent Claim
17 words
The device of claim 1 wherein, the logic means is comprised of a microprocessor and an EPROM.
Claim 10
Independent Claim
300 words
A method for connecting a local area network to a backbone network comprising the steps of: connecting a first interface co-processor to a local area network; connecting a second interface co-processor to a backbone network; connecting a memory means to said first and second interface co-processors, said memory means containing a NIM identification address and a table of addresses; connecting a logic means to said first and second interface co-processors and said memory means; receiving a local area network message in said first interface co-processor and temporarily storing said local area network message in said memory means; using the logic means to store information from a source address in said local area network message in said table of addresses; using said logic means to compare a destination address in said local area network message with said table addresses, and if the destination address is associated with the NIM identification address stored in said memory means, then ignoring said local area network message, and if the destination address is associated with the identification address of a second NIM, then enveloping said local area network message in a backbone network message addressed to said second NIM, and if the destination address is not associated with any of the addresses in said address table, then enveloping said local area network message in a backbone network message addressed to be multicast to all other NIM on said backbone network; receiving and evaluating a backbone network message at said second interface co-processor and temporarily storing said backbone network message in said memory means if said backbone network message is valid; using said logic means for storing source address information in said backbone message in said table of addresses; and using said logic means for de-enveloping said backbone message for transmission to said local area network.
Claim 11
Independent Claim
300 words
A method for connecting a local area network to a backbone network comprising the steps of: connecting a first interface co-processor to a local area network; connecting a second interface co-processor to a backbone network; connecting a memory means to said first and second interface co-processors, said memory means containing a NIM identification address and a table of addresses; connecting a logic means to said first and second interface co-processors and said memory means; receiving a local area network message in said first interface co-processor and temporarily storing said local area network message in said memory means; using the logic means to store information from a source address in said local area network message in said table of addresses; using said logic means to compare a destination address in said local area network message with said table addresses, and if the destination address is associated with the NIM identification address stored in said memory means, then ignoring said local area network message, and if the destination address is associated with the identification address of a second NIM, then enveloping said local area network message in a backbone network message addressed to said second NIM, and if the destination address is not associated with any of the addresses in said address table, then enveloping said local area network message in a backbone network message addressed to be multicast to all other NIM on said backbone network; receiving and evaluating a backbone network message at said second interface co-processor and temporarily storing said backbone network message in said memory means if said backbone network message is valid; using said logic means for storing source address information in said backbone message in said table of addresses; and using said logic means for de-enveloping said backbone message for transmission to said local area network.
References Cited (Backward Citations)
No citation records indexed.
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