EP0163577A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Local area network for digital data processing system
Assignee: Digital Equipment Corp
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Filing: 1985-05-24
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Granted: —
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Expires: 2005-05-24
Abstract
Abstract A local area network for interconnecting terminals and other users and data processing systems and other service providers over a communications link. The users and providers connect to the communications link by means of interface units each of which may connect to several users or providers. The interface units communicate over the communications link by means of messages. When a user requires the use of a service, the interface unit establishes a virtual circuit between it and the interface unit connected to the service provider and a service session which allows the user and the service provider to communicate over the virtual circuit. If several users connected to the one interface unit as the first user require services provided by providers which connected to the same interface unit as the first provider, they communicate in sessions over the same virtual circuits. The sessions messages are accumulated into single virtual circuit messages that are acknowledged in unison by the receiving interface unit. Each virtual circuit in the users' interface units includes a timer which reset when a message is transmitted over the virtual circuit and a data waiting flag set whenever data is present to be transmitted over the virtual circuit. The interface units are inhibited from transmitting over a virtual circuit unless the timer has timed out and the data waiting flag is set.
Inventors
- 👤 Bruce Mann
- 👤 Darrell Duffy
- 👤 Anthony Lauck
- 👤 William Strecker
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 10:29
CPC Classifications
H; H04; H04L; H04L69/00; H04L69/30; H04L69/32; H04L69/322; H04L69/326; H04L9/00; H04L9/40; H04L67/00; H04L67/01; H04L67/50; H04L67/51; H04L67/54; H04L69/18; H04L69/24; H04L69/28; H04L69/329
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
176 words
A local area network for interconnecting service users and service providers, including a plurality of device server units each of which connects to a service user and a plurality of nodes each connected to a service provider and a communications link to effect communications between the nodes and device server units to enable said service users and service providers to communicate, A. each node including means for transmitting a service advertising message over said communications link to identify the services provided by the service providers connected thereto, and B. each device server unit including: i. advertising message receiving means connected to said communications link for receiving said service advertising message; ii. service table means for establishing a service table including a plurality of entries each including a node field and a service field identifying a node and a service provided by the service providers connected to the node; and iii. selection means responsive to an operator requesting a service for using said service table to select the node and service provider to provide the requested service.
Claim 2
Dependent Claim
176 words
A local area network for interconnecting service users and service providers, including a plurality of device server units each of which connects to a service user and a plurality of nodes each connected to a service provider and a communications link to effect communications between the nodes and device server units to enable said service users and service providers to communicate, A. each node including means for transmitting a service advertising message over said communications link to identify the services provided by the service providers connected thereto, and B. each device server unit including: i. advertising message receiving means connected to said communications link for receiving said service advertising message; ii. service table means for establishing a service table including a plurality of entries each including a node field and a service field identifying a node and a service provided by the service providers connected to the node; and iii. selection means responsive to an operator requesting a service for using said service table to select the node and service provider to provide the requested service.
Claim 3
Dependent Claim
93 words
A node for connection in a local area network, the network interconnecting service users and service providers and including a plurality of device server units each of which connects to a service user and a plurality of nodes each connected to a service provider and a communications link to effect communications between the nodes and device server units to enable said service users and service providers to communicate the node including means for transmitting a service advertising message over said communications link to identify the services provided by the service providers connected thereto.
Claim 4
Dependent Claim
93 words
A node for connection in a local area network, the network interconnecting service users and service providers and including a plurality of device server units each of which connects to a service user and a plurality of nodes each connected to a service provider and a communications link to effect communications between the nodes and device server units to enable said service users and service providers to communicate the node including means for transmitting a service advertising message over said communications link to identify the services provided by the service providers connected thereto.
Claim 5
Independent Claim
182 words
A device server unit for connection in a local area network, the network interconnecting service users and service providers and including a plurality of device server units each of which connects to a service user and a plurality of nodes each connected to a service provider and a communications link to effect communications between the nodes and device server units to enable said service users and service providers to communicate, each node including means for transmitting a service advertising message over said communications link to identify the services provided by the service providers connected thereto, the device server unit including: A. advertising message receiving means connected to said communications link for receiving said service advertising message; B. service table means for establishing a service table including a plurality of entries each including a node field and a service field identifying a node and a service provided by the service providers connected to the node; and C. selection means responsive to an operator requesting a service for using said service table to select the node and service provider to provide the requested service.
Claim 6
Independent Claim
182 words
A device server unit for connection in a local area network, the network interconnecting service users and service providers and including a plurality of device server units each of which connects to a service user and a plurality of nodes each connected to a service provider and a communications link to effect communications between the nodes and device server units to enable said service users and service providers to communicate, each node including means for transmitting a service advertising message over said communications link to identify the services provided by the service providers connected thereto, the device server unit including: A. advertising message receiving means connected to said communications link for receiving said service advertising message; B. service table means for establishing a service table including a plurality of entries each including a node field and a service field identifying a node and a service provided by the service providers connected to the node; and C. selection means responsive to an operator requesting a service for using said service table to select the node and service provider to provide the requested service.
Claim 7
Dependent Claim
188 words
A local area network for interconnecting service users and service providers, including a plurality of device server units each of which connects to a service user and a plurality of nodes each connected to a service provider and a communications link to effect transfers of messages between the nodes and device server units to enable said service users and service providers to communicate, each said device server unit including: A. timing means for generating a timing signal at the end of a predetermined timing interval; B . data storage means for accumulating data from said service users for transmission to said service providers; C. data waiting flag means connected to said data storage means and having a set condition when data is stored in said data storage means and a reset condition; and D. message transmission means connected to said communications link, said timing means, said data storage means and said data waiting flag means for transferring data from said data storage means over said communications link in response to the data waiting flag means having a set condition if said timing means has generated the timing signal.
Claim 8
Dependent Claim
188 words
A local area network for interconnecting service users and service providers, including a plurality of device server units each of which connects to a service user and a plurality of nodes each connected to a service provider and a communications link to effect transfers of messages between the nodes and device server units to enable said service users and service providers to communicate, each said device server unit including: A. timing means for generating a timing signal at the end of a predetermined timing interval; B . data storage means for accumulating data from said service users for transmission to said service providers; C. data waiting flag means connected to said data storage means and having a set condition when data is stored in said data storage means and a reset condition; and D. message transmission means connected to said communications link, said timing means, said data storage means and said data waiting flag means for transferring data from said data storage means over said communications link in response to the data waiting flag means having a set condition if said timing means has generated the timing signal.
Claim 9
Dependent Claim
47 words
A local area network as defined in claim 4 wherein said node includes node message transmission means connected to said service providers and said communications link for transmitting messages to a device server unit in response to the receipt of a message from a device server unit.
Claim 10
Dependent Claim
65 words
A local area network as defined in claim 5 wherein each message originating at a node includes a response requested flag field having selected values, said device server unit further having message receiving means for receiving messages, said message receiving means including means for setting said data waiting flag means in response to the response requested flag field of a message having a predetermined value.
Claim 11
Dependent Claim
125 words
A local area network as defined in claim 6 wherein a message from said node to said device server unit includes a data field for transferring data from said node to said device server unit, said node transmitting a message having a response requested flag field having said predetermined value when said data field includes data and having the other predetermined value when said data field is empty, said node message transmission means thereafter being inhibited from sending another message when said response requested flag has said first predetermined value until the node receives a subsequent message from said communications link, said node message transmission means being enabled to send another message at any time when said response requested flag has said other predetermined value.
Claim 12
Independent Claim
196 words
A device server unit for connection in a local area network for interconnecting service users and service providers, the network including a plurality of device server units each of which connects to a service user and a plurality of nodes each connected to a service provider and a communications link to effect transfers of messages between the nodes and device server units to enable said service users and service providers to communicate, each said device server unit including: A. timing means for generating a timing signal at the end of a predetermined timing interval; B. data storage means for accumulating data from said service users for transmission to said service providers; C. data waiting flag means connected to said data storage means and having a set condition when data is stored in said data storage means and a reset condition; and D. message transmission means connected to said communications link, said timing means, said data storage means and said data waiting flag means for transferring data from said data storage means over said communications link in response to the data waiting flag means having a set condition if said timing means has generated the timing signal.
Claim 13
Independent Claim
196 words
A device server unit for connection in a local area network for interconnecting service users and service providers, the network including a plurality of device server units each of which connects to a service user and a plurality of nodes each connected to a service provider and a communications link to effect transfers of messages between the nodes and device server units to enable said service users and service providers to communicate, each said device server unit including: A. timing means for generating a timing signal at the end of a predetermined timing interval; B. data storage means for accumulating data from said service users for transmission to said service providers; C. data waiting flag means connected to said data storage means and having a set condition when data is stored in said data storage means and a reset condition; and D. message transmission means connected to said communications link, said timing means, said data storage means and said data waiting flag means for transferring data from said data storage means over said communications link in response to the data waiting flag means having a set condition if said timing means has generated the timing signal.
Claim 14
Dependent Claim
73 words
A device server unit as defined in claim 8 wherein a message from a node to said device server unit includes a response requested flag field having selected values, said device server unit further including message receiving means for receiving messages from said communications link, said message receiving means including means for setting said data waiting flag means in response to a response requested flag field having predetermined ones of said selected values.
Claim 15
Dependent Claim
160 words
A node for connection in a local area network for interconnecting service users and service providers, the network including a plurality of device server units each of which connects to a service user and a plurality of nodes each connected to a service provider and a communications link to effect transfers of messages between the nodes and device server units to enable said service users and service providers to communicate, each said device server unit including means for transmitting messages in response to the setting of a data waiting flag means normally indicating that it has data to send on the timing out of a timing means, said node including message receiving means for receiving messages from the communications link and message transmission means for transmitting a message including a data field and a response requested flag field having selected values, the values of said response requested flag field being established in response to whether the data field is empty.
Claim 16
Dependent Claim
160 words
A node for connection in a local area network for interconnecting service users and service providers, the network including a plurality of device server units each of which connects to a service user and a plurality of nodes each connected to a service provider and a communications link to effect transfers of messages between the nodes and device server units to enable said service users and service providers to communicate, each said device server unit including means for transmitting messages in response to the setting of a data waiting flag means normally indicating that it has data to send on the timing out of a timing means, said node including message receiving means for receiving messages from the communications link and message transmission means for transmitting a message including a data field and a response requested flag field having selected values, the values of said response requested flag field being established in response to whether the data field is empty.
Claim 17
Dependent Claim
80 words
A node as defined in claim 10 further comprising inhibiting means connected to said message transmission means and said message receiving means for inhibiting said message transmission means from transmitting a message until said message receiving unit has received a message, and enabling means responsive to the value of the last transmitted response requested flag field for disabling said inhibiting means when the value of said response requested flag field indicated that the data field of the message was empty.
References Cited (Backward Citations)
No citation records indexed.
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