Patent US4449796A successfully refreshed from Google Patents.
EP0222584A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
A bridge for and a method for routeing signals between local area networks
Assignee: Science and Engineering Research Council (SERC)
•
Filing: 1986-11-04
•
Granted: —
•
Expires: 2006-11-04
Abstract
Abstract A bridge for routing signals between local area networks comprises a list (5A,5B) of source addresses of signal packets arriving at respective sides of the bridge. Means are provided for comparing the destination addresses of the signal packets by a comparator (4A,4B) with addresses in the respective lists. If the comparator does not generate a match, the signal packet is routed through the bridge. Source addresses of received signal packets are added to the respective list, irrespective of the outcome of the previous comparison, and means are provided to remove the oldest entry from each list of source addresses when the list is filled to capacity.
Inventors
- 👤 Michael John Hampshire
- 👤 Edward Ball
- 👤 Nigel Linge
- 👤 Edward Charles Garnet Owen
- 👤 Paul Stephen Kummer
- 👤 Robin Tasker
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 14:49
CPC Classifications
H; H04; H04L; H04L45/00; H04L45/74; H04L45/742; H04L12/00; H04L12/28; H04L12/46; H04L12/4604; H04L12/462; H04L12/4625; H04L45/02; H04L45/04; H04L45/42
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
103 words
A bridge for bridging between local area networks comprising means for providing a list of source addresses of signal packets arriving on each side of the bridge, means for comparing the destination address of a received packet with the respective list of source addresses, means for routeing a packet through the bridge if the comparator means does not generate a match, means to add the source address of a received packet to the respective list of source addresses irrespective of the previous comparison and means to remove the oldest entry from a list of source addresses when the list is filled to capacity.
Claim 2
Dependent Claim
103 words
A bridge for bridging between local area networks comprising means for providing a list of source addresses of signal packets arriving on each side of the bridge, means for comparing the destination address of a received packet with the respective list of source addresses, means for routeing a packet through the bridge if the comparator means does not generate a match, means to add the source address of a received packet to the respective list of source addresses irrespective of the previous comparison and means to remove the oldest entry from a list of source addresses when the list is filled to capacity.
Claim 3
Dependent Claim
37 words
A bridge as claimed in claim l, comprising means for recording the age of each signal packet queuing for transmission and means to disable the transmission of the signal packet if its age exceeds a known limit.
Claim 4
Dependent Claim
79 words
A bridge as claimed in claim l or 2, comprising means to detect the presence of loops formed by bridges, means to generate a special bridge signal packet in the event that the bridge both transmits and receives the same bridge signal packet on the same side thereof, means to compare the priority of that special bridge signal packet and means to disable the means for routeing a signal packet through the bridge in dependence upon the priority detected.
Claim 5
Dependent Claim
55 words
A bridge as claimed in claim l,2 or 3, comprising means to determine if a bridge should transmit a further bridge signal packet at predetermined intervals, means to receive further bridge signal packets and means to enable the means for routeing a signal packet through the bridge if the absence of a loop is detected.
Claim 6
Dependent Claim
47 words
A bridge as claimed in any of claims l to 4,comprising means to detect the repeated arrival of a further bridge signal packet, and means to transmit a bridge signal packet in the event that the repeated arrival of the further bridge signal packet is not detected.
Claim 7
Dependent Claim
38 words
A bridge for bridging between local area networks comprising means to record for each signal packet queueing for transmission its age and means to disable the transmission of the signal packet if its age exceeds a known limit.
Claim 8
Dependent Claim
38 words
A bridge for bridging between local area networks comprising means to record for each signal packet queueing for transmission its age and means to disable the transmission of the signal packet if its age exceeds a known limit.
Claim 9
Dependent Claim
86 words
A bridge for bridging between local area networks comprising means to transmit and receive bridge signal packets, means to detect the presence of loops formed by bridges, means to generate a special bridge signal packet in the event that the bridge both transmits and receives the same bridge signal packet on the same side thereof, means to compare the priority of that special bridge signal packet and means to disable the means for routeing a signal packet through the bridge in dependence upon the priority detected.
Claim 10
Dependent Claim
86 words
A bridge for bridging between local area networks comprising means to transmit and receive bridge signal packets, means to detect the presence of loops formed by bridges, means to generate a special bridge signal packet in the event that the bridge both transmits and receives the same bridge signal packet on the same side thereof, means to compare the priority of that special bridge signal packet and means to disable the means for routeing a signal packet through the bridge in dependence upon the priority detected.
Claim 11
Independent Claim
100 words
A method of operating a bridge for bridging between local area networks including the steps of providing a list of source addresses of signal packets arriving on each side of the bridge, comparing the destination address of a received packet with the respective list of source addresses, routeing a packet through the bridge if the comparator means does not generate a match, adding the source address of a received packet to the respective list of source addresses irrespective of the previous comparison and removing the oldest entry from a list of source addresses when the list is filled to capacity.
Claim 12
Independent Claim
100 words
A method of operating a bridge for bridging between local area networks including the steps of providing a list of source addresses of signal packets arriving on each side of the bridge, comparing the destination address of a received packet with the respective list of source addresses, routeing a packet through the bridge if the comparator means does not generate a match, adding the source address of a received packet to the respective list of source addresses irrespective of the previous comparison and removing the oldest entry from a list of source addresses when the list is filled to capacity.
Claim 13
Dependent Claim
36 words
A method as claimed in claim 8, including the steps of recording for each signal packet queueing for transmission its age and disabling the transmission of the signal packet if its age exceeds a known limit.
Claim 14
Dependent Claim
80 words
l0. A method as claimed in claim 8 or 9, including the steps of transmitting and receiving bridge signal packets, detecting the presence of loops formed by bridges, generating a special bridge signal packet in the event that the bridge both transmits and receives the same bridge signal packet on the same side thereof, comparing the priority of that special bridge signal packet and disabling means for routeing a signal packet through the bridge in dependence upon the priority detected.
Claim 15
Dependent Claim
51 words
A method as claimed in claim 8, 9 or l0, including the steps of determining if a bridge should transmit a further bridge signal packet at predetermined intervals, receiving further bridge signal packets and enabling routeing of a signal packet through the bridge if the absence of a loop is detected.
Claim 16
Independent Claim
47 words
A method as claimed in any of claims 8 to ll, including the steps of detecting the repeated arrival of a further bridge signal packet, and transmitting a bridge signal packet, in the event that the repeated arrival of the further bridge signal packet is not detected.
Claim 17
Independent Claim
41 words
A method of operating a bridge for bridging between local area networks including the steps of recording for each signal packet queueing for transmission its age and disabling the transmission of the signal packet if its age exceeds a known limit.
Claim 18
Independent Claim
41 words
A method of operating a bridge for bridging between local area networks including the steps of recording for each signal packet queueing for transmission its age and disabling the transmission of the signal packet if its age exceeds a known limit.
Claim 19
Independent Claim
82 words
A method of operating a bridge for bridging between local area networks including the steps of transmitting and receiving bridge signal packets, detecting the presence of loops formed by bridges, generating a special bridge signal packet in the event that the bridge both transmits and receives the same bridge signal packet on the same side thereof, comparing the priority of that special bridge signal packet and disabling means for routeing a signal packet through the bridge in dependence upon the priority detected.
Claim 20
Independent Claim
82 words
A method of operating a bridge for bridging between local area networks including the steps of transmitting and receiving bridge signal packets, detecting the presence of loops formed by bridges, generating a special bridge signal packet in the event that the bridge both transmits and receives the same bridge signal packet on the same side thereof, comparing the priority of that special bridge signal packet and disabling means for routeing a signal packet through the bridge in dependence upon the priority detected.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.