Patent US4300274A successfully refreshed from Google Patents.
Patent US6061728A successfully refreshed from Google Patents.
US6061728A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Arrangement for controlling network proxy device traffic on a transparently-bridged local area network using a master proxy device
Assignee: Cisco Technology Inc
•
Filing: 1999-05-25
•
Granted: 2000-05-09
•
Expires: 2019-05-25
Abstract
Abstract A transparently-bridged wide area network connecting Ethernet/IEEE 802.3-based local area networks uses redundant proxy devices on each LAN for internetwork communications. The proxy devices on a given LAN, implemented as data link switching (DLSw) devices, identify amongst each other a master proxy device for mediating services to be provided to an end station on the local area network. Each proxy device connected to the local area network sends a request to the identified master proxy device in response to detecting a frame transmitted by an end station on the local area network, for permission to establish a circuit connection for transfer of the frame via a wide area network. The master proxy device, based on prescribed criteria, selects one of the proxy devices for transferring the frame, and sends a grant response to the selected proxy device. The master proxy device sends an "inuse" response as a denial response to the other proxy devices indicating the corresponding request has been denied, thereby avoiding contention for proxy services. Databases within the proxy devices track the request, grants, and denials to minimize generation of repeated requests. The inventory of granted requests may also be modified based on failures detected within the master proxy device, or any proxy device having received grants. Hence, redundant DLSw-type proxy devices may be implemented on a local area network while maintaining a stable and a robust communications system.
Inventors
- 👤 Andrew Joseph Mead
- 👤 Frank Gerard Bordonaro
- 👤 John Lautmann
- 👤 Scott Allen Bales
- 👤 Uwe Sellentin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:12
CPC Classifications
H; H04; H04L; H04L12/00; H04L12/28; H04L12/46; H04L12/4604; H04L12/462
Claims Analysis
Total Claims: 51
Claim 1
Independent Claim
170 words
A method of intercommunication between first and second local area networks via a wide area network, the method comprising: identifying a master proxy device from among at least two proxy devices coupled to the first local area network; receiving by the proxy devices a frame transmitted by a first end station onto the first local area network for transfer to the second local area network via the wide area network; sending a request to the master proxy device, by at least one of the other proxy devices on the first local area network, to transfer the frame to the second local area network; outputting a response by the master proxy device onto the first local area network to the at least one other proxy device indicating whether the corresponding request is granted; and determining whether a circuit connection may be initiated via the wide area network for transfer of the frame, by the at least one other proxy device, based on the corresponding response received from the master proxy device.
Claim 2
Independent Claim
170 words
A method of intercommunication between first and second local area networks via a wide area network, the method comprising: identifying a master proxy device from among at least two proxy devices coupled to the first local area network; receiving by the proxy devices a frame transmitted by a first end station onto the first local area network for transfer to the second local area network via the wide area network; sending a request to the master proxy device, by at least one of the other proxy devices on the first local area network, to transfer the frame to the second local area network; outputting a response by the master proxy device onto the first local area network to the at least one other proxy device indicating whether the corresponding request is granted; and determining whether a circuit connection may be initiated via the wide area network for transfer of the frame, by the at least one other proxy device, based on the corresponding response received from the master proxy device.
Claim 3
Dependent Claim
27 words
The method of claim 1, further comprising initiating the circuit connection by one of the proxy devices having received a grant response from the master proxy device.
Claim 4
Dependent Claim
27 words
The method of claim 2, wherein the receiving step includes receiving the frame from the first local area network according to an Ethernet IEEE 802.3 based protocol.
Claim 5
Dependent Claim
99 words
The method of claim 2, wherein the sending step includes sending a plurality of requests from the other proxy devices, respectively, the outputting step comprising: starting a timer in the master proxy device in response to reception of a first of the requests; in response to a prescribed time interval having elapsed in the timer, selecting from a group of the requests, received by the master proxy device within the prescribed time interval, one of the requests for granting initiation of the circuit connection; and generating the grant response for the one proxy device corresponding to the one request.
Claim 6
Dependent Claim
25 words
The method of claim 4, further comprising generating in-use responses to remaining ones of the proxy devices having not been sent the grant response, respectively.
Claim 7
Dependent Claim
55 words
The method of claim 5, further comprising storing, in each of the remaining ones of the proxy devices, the corresponding in-use response indicating denial of the corresponding request in a denial database, each proxy device selectively generating subsequent requests to the master proxy device based on the in-use response stored in the corresponding denial database.
Claim 8
Dependent Claim
48 words
The method of claim 2, further comprising storing a grant entry in a database in the master proxy device indicating generation of the grant response, the master proxy device selectively granting subsequent requests for respective initiation of subsequent circuit connections based on the grant stored in the database.
Claim 9
Dependent Claim
67 words
The method of claim 7, wherein the request includes a source address of the first end station and a destination address specifying a second end station on the second local area network, the step of storing the grant entry including storing an identity of the one proxy device having received the corresponding grant response, and the source and destination addresses of the frame corresponding to the request.
Claim 10
Dependent Claim
50 words
The method of claim 8, further comprising forwarding frames between the first and second end stations via the circuit connection on the wide area network by the one proxy device having received the corresponding grant response, without generating further requests to the master proxy device, based on the grant response.
Claim 11
Dependent Claim
69 words
The method of claim 9, further comprising: detecting a disconnect condition in the circuit connection by the one proxy device having received the corresponding grant response; sending a circuit release message by the one proxy device having received the corresponding grant response in response to the detected disconnect condition; and removing the grant entry by the master proxy device from the database in response to the circuit release message.
Claim 12
Dependent Claim
39 words
The method of claim 7, further comprising: detecting by the master proxy device a failure in the one proxy device having received the grant response; and deleting the grant entry from the database in response to the detected failure.
Claim 13
Dependent Claim
37 words
The method of claim 1, further comprising selecting by the master proxy device to initiate the circuit connection, the outputting step including outputting an in-use message as the response to the at least one other proxy device.
Claim 14
Dependent Claim
40 words
The method of claim 1, wherein the outputting step includes outputting in-use messages for all the requests based on a prescribed condition detected by the master proxy device, to prevent transfer of the frame to the second local area network.
Claim 15
Dependent Claim
25 words
The method of claim 1, further comprising transmitting one of a SABME frame and an XID frame as said frame by the first end station.
Claim 16
Dependent Claim
33 words
The method of claim 1, further comprising: detecting a failure in the master proxy device; and identifying a new master proxy device between the other proxy devices in response to the detected failure.
Claim 17
Dependent Claim
135 words
A local area network configured for internetwork communications via a wide area network, the local area network comprising: a first end station configured for outputting a frame onto the local area network; and proxy devices configured for establishing a circuit connection on the wide area network for transfer of the frame to another network, including: (1) a master proxy device configured for receiving requests for establishment of said circuit connection, the master proxy device selectively outputting a response indicating whether one of the requests is granted, and (2) at least one other proxy device for sending a corresponding one of the requests in response to reception of the frame, the at least one other proxy device determining whether the circuit connection may be initiated based on the corresponding response received from the master proxy device.
Claim 18
Dependent Claim
135 words
A local area network configured for internetwork communications via a wide area network, the local area network comprising: a first end station configured for outputting a frame onto the local area network; and proxy devices configured for establishing a circuit connection on the wide area network for transfer of the frame to another network, including: (1) a master proxy device configured for receiving requests for establishment of said circuit connection, the master proxy device selectively outputting a response indicating whether one of the requests is granted, and (2) at least one other proxy device for sending a corresponding one of the requests in response to reception of the frame, the at least one other proxy device determining whether the circuit connection may be initiated based on the corresponding response received from the master proxy device.
Claim 19
Dependent Claim
64 words
The network of claim 16, wherein the master proxy device generates a grant response to a selected one of the proxy devices in response to the requests, the master proxy device including a database for storing a grant entry identifying the grant response and the corresponding selected one proxy device, the master proxy device selectively granting subsequent requests based on the stored grant entry.
Claim 20
Dependent Claim
43 words
The network of claim 17, wherein each one of the proxy devices includes a database for storing the corresponding response received from the master proxy device, each proxy device selectively generating a corresponding one of the subsequent requests based on the stored response.
Claim 21
Dependent Claim
47 words
The network of claim 17, wherein the master proxy device, in response to detecting a failure in the selected one proxy device having received the grant response, deletes the grant entry in the database for reassignment of the circuit connection to another one of the proxy devices.
Claim 22
Dependent Claim
32 words
The network of claim 16, wherein the at least one other proxy device, in response to detecting a failure in the master proxy device, designates itself as a new master proxy device.
Claim 23
Independent Claim
151 words
A method in a proxy device coupled to a local area network and configured for establishing a circuit connection with another local area network via a wide area network, the method comprising: establishing a communication with at least a second proxy device coupled to the local area network; determining the proxy device to be a master proxy device for the local area network from among the proxy device and the at least second proxy device coupled to the local area network; receiving a request from the at least second proxy device for establishing the circuit connection to the another local area network; selecting whether one of the proxy device and the at least second proxy device should establish the circuit connection in response to the received request; and sending a response to the at least second proxy device, based on the selecting step, indicating whether the corresponding request has been granted.
Claim 24
Independent Claim
151 words
A method in a proxy device coupled to a local area network and configured for establishing a circuit connection with another local area network via a wide area network, the method comprising: establishing a communication with at least a second proxy device coupled to the local area network; determining the proxy device to be a master proxy device for the local area network from among the proxy device and the at least second proxy device coupled to the local area network; receiving a request from the at least second proxy device for establishing the circuit connection to the another local area network; selecting whether one of the proxy device and the at least second proxy device should establish the circuit connection in response to the received request; and sending a response to the at least second proxy device, based on the selecting step, indicating whether the corresponding request has been granted.
Claim 25
Dependent Claim
36 words
The method of claim 21, further comprising adding an entry to a denial database based on the selecting step, the denial database storing entries for each of the proxy devices having been denied the corresponding request.
Claim 26
Dependent Claim
47 words
The method of claim 22, wherein the request includes source and destination addresses, the adding step including adding a plurality of entries for the respective proxy devices indicating no circuit connection is to be established for the source and destination addresses in response to the corresponding request.
Claim 27
Dependent Claim
39 words
The method of claim 21, further comprising adding an entry to a grant database based on the selecting step, the master database storing entries identifying the one proxy device selected to establish the circuit connection and the corresponding request.
Claim 28
Dependent Claim
26 words
The method of claim 24, further comprising deleting the entry from the grant database in response to a circuit release message from the one proxy device.
Claim 29
Dependent Claim
33 words
The method of claim 24, further comprising deleting the entry from the grant database in response to a detected failure in the communication between the master proxy device and the one proxy device.
Claim 30
Independent Claim
129 words
A method in a proxy device coupled to a local area network and configured for establishing a circuit connection with another local area network via a wide area network, the method comprising: establishing a communication with at least a second proxy device coupled to the local area network; determining the second proxy device to be a master proxy device for the local area network; sending a request to the master proxy device, in response to reception of a frame transmitted by an end station on the local area network, for establishing the circuit connection to the another local area network for transfer of the frame; and selectively establishing the circuit connection based on a response, received from the master proxy device, indicating whether the corresponding request has been granted.
Claim 31
Independent Claim
129 words
A method in a proxy device coupled to a local area network and configured for establishing a circuit connection with another local area network via a wide area network, the method comprising: establishing a communication with at least a second proxy device coupled to the local area network; determining the second proxy device to be a master proxy device for the local area network; sending a request to the master proxy device, in response to reception of a frame transmitted by an end station on the local area network, for establishing the circuit connection to the another local area network for transfer of the frame; and selectively establishing the circuit connection based on a response, received from the master proxy device, indicating whether the corresponding request has been granted.
Claim 32
Dependent Claim
53 words
The method of claim 27, further comprising adding an entry to a denial database based on the response indicating the corresponding request has been denied, the proxy device selectively outputting another request to the master proxy device, in response to a corresponding subsequent frames from the end station, based on the added entry.
Claim 33
Dependent Claim
44 words
The method of claim 27, further comprising adding an entry to a grant database based on the response indicating the corresponding request has been granted, the proxy device forwarding subsequent frames between the circuit connection and the end station based on the added entry.
Claim 34
Dependent Claim
40 words
The method of claim 29, further comprising: detecting a circuit disconnect in the circuit connection; deleting the entry from the grant database; and outputting a circuit release message indicating the circuit connection has been disconnected to the master proxy device.
Claim 35
Dependent Claim
135 words
A proxy device configured for establishing a circuit connection between a local area network and another local area network via a wide area network, the proxy device including: a first network port for communication with a second proxy device via the local area network; a second network port for communication with the another local area network via the wide area network; a database for identifying one of the proxy device and the second proxy device as a master proxy device; and a control unit configured for one of (1) sending a request for establishment of the circuit connection for a received frame to the second proxy device, and (2) selecting whether one of the proxy device and the second proxy device should establish the circuit connection, based on the database identifying the master proxy device.
Claim 36
Dependent Claim
135 words
A proxy device configured for establishing a circuit connection between a local area network and another local area network via a wide area network, the proxy device including: a first network port for communication with a second proxy device via the local area network; a second network port for communication with the another local area network via the wide area network; a database for identifying one of the proxy device and the second proxy device as a master proxy device; and a control unit configured for one of (1) sending a request for establishment of the circuit connection for a received frame to the second proxy device, and (2) selecting whether one of the proxy device and the second proxy device should establish the circuit connection, based on the database identifying the master proxy device.
Claim 37
Dependent Claim
30 words
The proxy device of claim 31, further comprising a grant database for storing a grant entry indicating whether the proxy device has been granted permission to establish the circuit connection.
Claim 38
Dependent Claim
26 words
The proxy device of claim 32, wherein the control unit deletes the grant entry in response to a detected circuit disconnect by the second network port.
Claim 39
Dependent Claim
29 words
The proxy device of claim 31, further comprising a denial database for storing an entry indicating whether the proxy device has been denied permission to establish the circuit connection.
Claim 40
Dependent Claim
167 words
A computer readable medium having stored thereon sequences of instructions for selectively establishing, by a proxy device coupled to a first local area network, a circuit connection with another local area network via a wide area network, the sequences of instructions including instructions for performing the steps of: establishing a communication with at least a second proxy device coupled to the local area network; determining the proxy device to be a master proxy device for the local area network from among the proxy device and the at least second proxy device coupled to the local area network; receiving a request from the at least second proxy device for establishing the circuit connection to the another local area network; selecting whether one of the proxy device and the at least second proxy device should establish the circuit connection in response to the received request; and sending a response to the at least second proxy device, based on the selecting step, indicating whether the corresponding request has been granted.
Claim 41
Dependent Claim
167 words
A computer readable medium having stored thereon sequences of instructions for selectively establishing, by a proxy device coupled to a first local area network, a circuit connection with another local area network via a wide area network, the sequences of instructions including instructions for performing the steps of: establishing a communication with at least a second proxy device coupled to the local area network; determining the proxy device to be a master proxy device for the local area network from among the proxy device and the at least second proxy device coupled to the local area network; receiving a request from the at least second proxy device for establishing the circuit connection to the another local area network; selecting whether one of the proxy device and the at least second proxy device should establish the circuit connection in response to the received request; and sending a response to the at least second proxy device, based on the selecting step, indicating whether the corresponding request has been granted.
Claim 42
Dependent Claim
44 words
The computer readable medium of claim 35, further comprising instructions for performing the steps of adding an entry to a denial database based on the selecting step, the denial database storing entries for each of the proxy devices having been denied the corresponding request.
Claim 43
Dependent Claim
49 words
The computer readable medium of claim 36, wherein the request includes source and destination addresses, the adding step including adding a plurality of entries for the respective proxy devices indicating no circuit connection is to be established for the source and destination addresses in response to the corresponding request.
Claim 44
Dependent Claim
47 words
The computer readable medium of claim 35, further comprising instructions for performing the steps of adding an entry to a grant database based on the selecting step, the master database storing entries identifying the one proxy device selected to establish the circuit connection and the corresponding request.
Claim 45
Dependent Claim
34 words
The computer readable medium of claim 38, further comprising instructions for performing the steps of deleting the entry from the grant database in response to a circuit release message from the one proxy device.
Claim 46
Dependent Claim
41 words
The computer readable medium of claim 38, further comprising instructions for performing the steps of deleting the entry from the grant database in response to a detected failure in the communication between the master proxy device and the one proxy device.
Claim 47
Dependent Claim
145 words
A computer readable medium having stored thereon sequences of instructions for selectively establishing, by a proxy device coupled to a first local area network, a circuit connection with another local area network via a wide area network, the sequences of instructions including instructions for performing the steps of: establishing a communication with at least a second proxy device coupled to the local area network; determining the second proxy device to be a master proxy device for the local area network; sending a request to the master proxy device, in response to reception of a frame transmitted by an end station on the local area network, for establishing the circuit connection to the another local area network for transfer of the frame; and selectively establishing the circuit connection based on a response, received from the master proxy device, indicating whether the corresponding request has been granted.
Claim 48
Dependent Claim
145 words
A computer readable medium having stored thereon sequences of instructions for selectively establishing, by a proxy device coupled to a first local area network, a circuit connection with another local area network via a wide area network, the sequences of instructions including instructions for performing the steps of: establishing a communication with at least a second proxy device coupled to the local area network; determining the second proxy device to be a master proxy device for the local area network; sending a request to the master proxy device, in response to reception of a frame transmitted by an end station on the local area network, for establishing the circuit connection to the another local area network for transfer of the frame; and selectively establishing the circuit connection based on a response, received from the master proxy device, indicating whether the corresponding request has been granted.
Claim 49
Dependent Claim
61 words
The computer readable medium of claim 41, further comprising instructions for performing the steps of adding an entry to a denial database based on the response indicating the corresponding request has been denied, the proxy device selectively outputting another request to the master proxy device, in response to a corresponding subsequent frames from the end station, based on the added entry.
Claim 50
Dependent Claim
52 words
The computer readable medium of claim 41, further comprising instructions for performing the steps of adding an entry to a grant database based on the response indicating the corresponding request has been granted, the proxy device forwarding subsequent frames between the circuit connection and the end station based on the added entry.
Claim 51
Dependent Claim
48 words
The computer readable medium of claim 43, further comprising instructions for performing the steps of: detecting a circuit disconnect in the circuit connection; deleting the entry from the grant database; and outputting a circuit release message indicating the circuit connection has been disconnected to the master proxy device.
References Cited (Backward Citations)
US5461611A
Cited
US5561669A
Cited
US5600644A
Cited
US5805805A
Cited
US5949779A
Cited
US5946311A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-05-09 | 2003-11-08 | 2004-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-05-09 | 2007-11-08 | 2008-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-05-09 | 2011-11-08 | 2012-05-09 | $7700.00 | Window Closed / Lapsed |