Network resource reservation with admission and link control functions separated for expandability and high-speed operation

A network resource reservation system for a reconfigurable transmission network which comprises a plurality of parallel circuits each comprising a series of links interconnected by one or more interconnection switches, at least one of the links of one of said circuits being commonly assigned to multiple user networks, each of said user networks transmitting a reservation request indicating a circuit assigned to the user network, a network resource desired to be allocated from the resource of the assigned circuit, and start and end times of a reservation, comprising:

• an interface connected to said user networks for receiving said request;
• a first database;
• a second database for storing network resources respectively assigned to said user networks;
• a resource allocation table;
• an admission controller connected to the interface, the admission controller being responsive to a reservation request received by the interface for accessing said first and second databases and said resource allocation table, informing the requesting user network from which the request was transmitted that the request is denied if the network resource desired by the request is greater than an amount remaining in the resource assigned to the requesting user network and informing the requesting user network of grant of the request and storing the request into said first database and available network resource of the requesting user network into the resource allocation table if the desired network resource is equal to or smaller than said amount, said admission controller being responsive to the end time of the stored request for removing the stored request from said first database and updating the resource allocation table;
• and
• link control means connected to an associated one of said interconnection switches, the link control means being responsive to the start time of the stored request for operating the associated interconnection switch to establish the desired network resource, and responsive to the end time of the stored request for releasing the associated interconnection switch to clear the established network resource.

A network resource reservation system for a reconfigurable transmission network which comprises a plurality of parallel circuits each comprising a series of links interconnected by one or more interconnection switches, at least one of the links of one of said circuits being commonly assigned to multiple user networks, each of said user networks transmitting a reservation request indicating a circuit assigned to the user network, a network resource desired to be allocated from the resource of the assigned circuit, and start and end times of a reservation, comprising:

• a plurality of interfaces connected to said user networks for receiving said request;
• a plurality of first databases;
• a plurality of second databases for storing network resources respectively assigned to said user networks;
• a resource allocation table;
• a plurality of admission controllers connected respectively to the interfaces and further connected respectively to the first databases and to the second databases, each of the admission controllers being responsive to a reservation request received by the interfaces for accessing the associated first and second databases and said resource allocation table, informing the requesting user network from which the request was transmitted that the request is denied if the network resource desired by the request is greater than an amount remaining in the resource assigned to the requesting user network and informing the requesting user network of grant of the request and storing the request into the associated first database and available network resource of the requesting user network into the resource allocation table if the desired network resource is equal to or smaller than said amount, said admission controller being responsive to the end time of the stored request for removing the stored request from the associated first database and updating the resource allocation table;
• and
• link control means connected to an associated one of said interconnection switches, the link control means being responsive to the start time of the stored request for operating the associated interconnection switch to establish the desired network resource, and responsive to the end time of the stored request for releasing the associated interconnection switch to clear the established network resource.

A network resource reservation system for a reconfigurable transmission network which comprises a plurality of parallel circuits each comprising a series of links interconnected by a plurality of interconnection switches, at least one of the links of one of said circuits being commonly assigned to multiple user networks, each of said user networks transmitting a reservation request indicating a circuit assigned to the user network, a network resource desired to be allocated from the resource of the assigned circuit, and start and end times of a reservation, comprising:

• an interface connected to said user networks for receiving said request;
• a first database;
• a second database for storing resources respectively assigned to said user networks;
• an admission controller connected to the interface, the admission controller being responsive to a reservation request received by the interface for accessing said first and second databases, informing the requesting user network from which the request was transmitted that the request is denied if the network resource desired by the request is greater than an amount remaining in the resource assigned to the requesting user network and informing the requesting user network of grant of the request and storing the request into said first database if the desired network resource is equal to or smaller than said amount, the admission controller being responsive to the end time of a request stored in the first database for removing the request from said first database;
• and
• a plurality of link control means connected respectively to said interconnection switches, each of the link control means being responsive to the start time of a request stored in the first database for operating the associated interconnection switch to establish the desired network resource of the stored request, and responsive to the end time of the stored request for releasing the associated interconnection switch to clear the established network resource.

A method for making a reservation of network resource by transmitting a request from a user who desires to establish a network resource in a reconfigurable transmission network which comprises a plurality of parallel circuits each comprising a series of links interconnected by one or more interconnection switches, at least one of the links of one of said circuits being commonly assigned to multiple users, said request indicating a circuit assigned to the user, a network resource desired to be allocated from the resource of the assigned circuit, and start and end timing of a reservation of the desired network resource, comprising the steps of:

• a) determining, in response to a reservation request from a user, whether or not the network resource desired by the request is available in the circuit assigned to the user;
• b) if the desired network resource is determined to be not available, informing said user of denial of the request, and if the desired network resource is determined to be available, storing the request into a database and informing said user of grant of the requests;
• c) producing a link control signal from the stored request and storing the link control signal into a memory;
• d) operating an associated one of the interconnection switches according to the link control signal of said memory to establish the desired network resource when the start timing of the request is reached and removing said link control signal from said memory;
• and
• e) producing a link control signal again from the stored request and releasing the associated interconnection switch according to the link control signal to clear the established network resource when the end timing of the request is reached and removing the stored request from said database.

A method for making a reservation of network resource by transmitting a request from a user who desires to establish a network resource in a reconfigurable transmission network which comprises a plurality of parallel circuits each comprising a series of links interconnected by one or more interconnection switches, at least one of the links of one of said circuits being commonly assigned to multiple users, said request indicating a circuit assigned to the user, a network resource desired to be allocated from the resource of the assigned circuit, and start and end times of a reservation, one of said switches including a working unit and a spare unit and first and second memories, said working unit initially operating according to data contained in the first memory, comprising the steps of:

• a) determining, in response to a reservation request from a user, whether or not the network resource desired by the request is available in the circuit assigned to the user;
• b) if the desired network resource is determined to be not available, informing said user of denial of the request, and if the desired network resource is determined to be available, storing the request into a database and informing said user of grant of the request;
• c) producing a link control signal from the stored request and storing the link control signal into said second memory;
• d) operating said working unit to establish the desired network resource according to the link control signal of said second memory when the start time of the request is reached;
• and
• e) releasing said working unit according to the link control signal of said second memory to clear the established network resource when the end time of the request is reached.

A method for making a reservation of network resource by transmitting a request from a user who desires to establish a network resource in a reconfigurable transmission network which comprises a plurality of parallel circuits each comprising a series of links interconnected by one or more interconnection switches, at least one of the links of one of said circuits being commonly assigned to multiple users, said request indicating a circuit assigned to the user, a network resource desired to be allocated from the resource of the assigned circuit, and start and end times of a reservation, comprising the steps of:

• a) determining, in response to a reservation request from a user, whether or not the network resource desired by the request is available in the circuit assigned to the user;
• b) if the desired network resource is determined to be not available, informing said user of denial of the request and if the desired network resource is determined to be available, informing said user of grant of the request;
• c) operating an associated one of the interconnection switches to establish the desired network resource of the request when the start time of the request is reached:
• d) repeating the steps (a) to (c) to establish a plurality of desired network resources in response to a plurality of reservation requests of successive arrivals;
• e) operating the associated interconnection switch to clear the established network resource of a previous request when the end time of the previous request is reached;
• f) operating the associated interconnection switch to establish the desired network resource of a subsequent request when the start time of the subsequent request is reached simultaneously with the end time of the previous request;
• and
• g) releasing the associated interconnection switch to clear the established network resource of the subsequent request when the end time of the subsequent request is reached.