Resource reallocation for flow-enforced user traffic

• US 5,315,586 A
• Filed: 06/29/1992
• Issued: 05/24/1994
• Est. Priority Date: 06/28/1991
• Status: Expired due to Term

• Current Assignee: Ciena Corporation
• Original Assignee: NEC Corporation
• Inventors: Charvillat, Eric
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): MARCELO, MELVIN C
• Application Number:
  US07/905,794
• Time in Patent Office: 694 Days
• Field of Search: 370/17, 370/60, 370/60.1, 370/61, 370/79, 370/84, 370/85.6, 370/85.7, 370/94.1, 370/94.2, 370/94.3, 370/95.1, 370/110.1, 370/118
• US Class Current: 370/232
• CPC Class Codes: H04L 12/5602 Bandwidth control in ATM Networks, e.g. leaky bucket
• CPC Class Codes: H04L 2012/5614 User Network Interface
• CPC Class Codes: H04L 2012/5619 Network Node Interface, e.g. tandem connections, transit switching
• CPC Class Codes: H04L 2012/5632 Bandwidth allocation
• CPC Class Codes: H04L 2012/5634 In-call negotiation
• CPC Class Codes: H04L 2012/5636 Monitoring or policing, e.g. compliance with allocated rate, corrective actions
• CPC Class Codes: H04L 49/3081 ATM peripheral units, e.g. policing, insertion or extraction
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections

Abstract

In a packet (ATM) network, a source node at the entry of the network is responsive to a connection request from a user terminal for invoking a CAC (call admission control) algorithm to accept or reject the request depending on the amount of resource requested by the user, and allocates a portion of a free bandwidth resource exclusively to the user for the duration of the call according to established contract parameter values. Each node of the network responds to a reallocation request from the user for transmitting a copy of the request to a downstream node to elicit an acceptance message therefrom, and reserving a portion of a pool bandwidth resource and invoking the CAC algorithm to additionally reserve a portion of the free bandwidth resource. The node proceeds to allocate the reserved pool bandwidth to the user in response to the acceptance message indicating that the same amount of the reserved pool bandwidth is available in the downstream node. The allocation of the pool bandwidth is temporary. When a portion of the free bandwidth resource is reserved using the CAC algorithm, this portion is exclusively allocated to the user until the end of the call and the temporarily allocated pool bandwidth is returned to the pool resource for other users.

Claims

1. A network node for a packet network comprising:

call admission control means responsive to a connection request from a user terminal for accepting or rejecting the connection request depending on the amount of resource requested by the user terminal, establishing a contract parameter value, and allocating a resource to said user terminal according to the established contract parameter value;

flow enforcement means including a buffer for allowing cells from said user terminal to be transmitted toward a destination terminal when said contract parameter value is not violated and storing the cells in said buffer when said contract parameter value is violated; and

resource reallocation means responsive to receipt of a reallocation request from said user terminal when occupancy of said buffer is higher than a predefined value and allocating an additional resource to said user terminal.

2. A network node as claimed in claim 1, wherein said resource reallocation means includes means responsive to receipt of a deallocation indication from said user terminal when the occupancy of said buffer is lower than a predefined value for deallocating a portion of the allocated resources.

3. A network node as claimed in claim 2, wherein said user terminal includes a buffer replica in the form of a counter indicating the number of violating cells stored in the buffer of said node, and means for detecting when said number is higher than said predefined value and generating said reallocation request.

4. A network node as claimed in claim 3, wherein said user terminal includes means for generating said deallocation indication when the occupancy of the buffer replica is lower than a second predefined value.

5. A packet network including a plurality of network nodes interconnected by transmission links, a source node of the network located at an entry of the network comprising flow enforcement means including a buffer for allowing cells from a user terminal to be transmitted toward a destination terminal when a contract parameter value is not violated and storing the cells in said buffer when said contract parameter value is violated, each of said network nodes comprising:

resource allocation means responsive to a connection request from said user terminal for invoking a call admission control (CAC) algorithm to accept or reject the connection request depending on the amount of resource requested by the user terminal, establishing said contract parameter value, and allocating a portion of a free bandwidth resource to said user terminal according to the established contract parameter value; and

resource reallocation means, responsive to a reallocation request transmitted from said user terminal when occupancy of said buffer is higher than a predefined value, for transmitting a copy of the reallocation request to a downstream node to elicit an acceptance signal therefrom, reserving a portion of a pool bandwidth resource and invoking said CAC algorithm to reserve a portion of said free bandwidth resource,

said resource reallocation means of said source node temporarily allocating said reserved portion of the pool bandwidth resource to said user terminal in response to said acceptance signal from the downstream node indicating that same amount of the reserved portion of the pool bandwidth resource is available in said downstream node, and permanently allocating said reserved portion of the free bandwidth resource to said user terminal and restoring the temporarily allocated portion of the pool bandwidth resource.

6. A packet network as claimed in claim 5, wherein said resource reallocation means includes means responsive to receipt of a deallocation indication from said user terminal when the occupancy of said buffer is lower than a second predefined value for deallocating part of the allocated resource portions.

7. A packet network as claimed in claim 5 or 6, wherein said user terminal includes a buffer replica in the form of a counter indicating the number of violating cells stored in the buffer of said source node, and means for detecting when said number is higher than said predefined value and generating said reallocation request.

8. A packet network as claimed in claim 5, wherein said resource reallocation means includes means responsive to receipt of a deallocation indication from said user terminal when the occupancy of said buffer is lower than a second predefined value for deallocating part of the allocated resource portions, and wherein said user terminal includes a buffer replica in the form of a counter indicating the number of violating cells stored in the buffer of said source node, means for detecting when said number is higher than said predefined value and generating said reallocation request, and means for detecting when the occupancy of the buffer replica is lower than a second predefined value and generating said deallocation indication.

9. A packet network comprising at least first and second interconnected network nodes, each of said nodes comprising resource allocation means responsive to a connection request from a user terminal for invoking a call admission control (CAC) algorithm to accept or reject the connection request depending on the amount of resource requested by the user terminal, establishing a contract parameter value, and allocating a portion of a free bandwidth resource to said user terminal according to the established contract parameter value,

said first node including:

flow enforcement means including a buffer for allowing cells from said user terminal to be transmitted toward a destination terminal when said contract parameter value is not violated and storing the cells in said buffer when said contract parameter value is violated; and

first resource reallocation means responsive to a reallocation request transmitted from said user terminal when occupancy of said buffer is higher than a predefined value for transmitting a copy of the reallocation request to said second node to elicit an acceptance signal therefrom and reserving a portion of a pool bandwidth resource, invoking said CAC algorithm to reserve a portion of said free bandwidth resource, said first resource reallocation means temporarily allocating the reserved portion of the pool bandwidth resource to the user terminal in response to the acceptance signal from the second node, transmitting a confirmation signal to the second node, and permanently allocating the reserved portion of the free bandwidth resource to the user terminal and restoring the temporarily allocated portion of the pool bandwidth resource,

said second node including;

second resource reallocation means responsive to the reallocation request from said first node for reserving a portion of a pool bandwidth resource, invoking said CAC algorithm to reserve a portion of the free bandwidth resource of the second node, transmitting said acceptance signal to said first node, said second resource reallocation means permanently allocating the reserved portion of the free bandwidth resource of the second node to the user terminal in response to said confirmation signal, and restoring the reserved portion of the pool bandwidth resource of the second node.

10. In a packet network comprising a plurality of interconnected nodes, each of the nodes including call admission control means responsive to a connection request from a user terminal for accepting or rejecting the connection request depending on the amount of resource requested by the user terminal, establishing a contract parameter value, and allocating a resource to said user terminal according to the established contract parameter value, one of said nodes located at an entry of the network comprising flow enforcement means including a buffer for allowing cells from said call-originating user terminal to be transmitted toward a destination terminal when said contract parameter value is not violated and storing the cells in said buffer when said contract parameter value is violated, a method for controlling traffic of said user terminal, comprising the steps of:

a) transmitting a reallocation request from said user terminal when occupancy of said buffer is higher than a predefined value; and

b) receiving said reallocation request at said one network node and allocating an additional resource to said user terminal in response to receipt of said request.

11. A method as claimed in claim 10, further comprising the steps of:

transmitting a deallocation indication from the user terminal when the occupancy of said buffer is lower than a second predefined value; and

receiving said deallocation indication at said one node for deallocating portion of the allocated resources in response to receipt of the deallocation indication.

12. In a packet network including a plurality of network nodes interconnected by transmission links, a source node of the network located at an entry of the network comprising flow enforcement means including a buffer for allowing cells from a call-originating user terminal to be transmitted toward a destination terminal when a contract parameter value is not violated and storing the cells in said buffer when said contract parameter value is violated, and each of said nodes comprising call admission control means responsive to a connection request from said user terminal for invoking a call admission control (CAC) algorithm to allocate a portion of a free bandwidth resource to said user terminal and establish said contract parameter value, a method for controlling traffic of the user terminal, comprising the steps of:

a) transmitting a reallocation request from the user terminal when occupancy of said buffer is higher than a predefined value;

b) receiving said reallocation request at said source node, transmitting a copy of the reallocation request to a downstream node to elicit an acceptance signal therefrom and reserving a portion of a pool bandwidth resource;

c) invoking said CAC algorithm to reserve a portion of said free bandwidth resource;

d) receiving said acceptance signal at said source node indicating that same amount of the portion of the pool bandwidth resource reserved by the step (b) is available in said downstream node and temporarily allocating the reserved portion of the pool bandwidth resource to said user terminal; and

e) permanently allocating the portion of the free bandwidth resource reserved by the step (c) to the user terminal and restoring the temporarily allocated portion of the pool bandwidth resource.

13. A method as claimed in claim 12, further comprising the steps of:

transmitting a deallocation indication from the user terminal when the occupancy of said buffer is lower than a second predefined value; and

receiving said deallocation indication at said source node and deallocating portion of the allocated resource portions.

14. In a packet network comprising a first node located at an entry of the network and a second node, said first node comprising flow enforcement means including a buffer for allowing cells from a user terminal to be transmitted toward a destination terminal when a contract parameter value is not violated and storing the cells in said buffer when said contract parameter value is violated, and each of said first and second nodes comprising call admission control means responsive to a connection request from the user terminal for invoking a call admission control (CAC) algorithm to allocate a portion of a free bandwidth resource to said user terminal and establish said contract parameter value, a method for controlling traffic of said user terminal, comprising the steps of:

a) transmitting a reallocation request from the user terminal when occupancy of said buffer is higher than a predefined value;

b) receiving said reallocation request at said first node, transmitting a copy of the reallocation request from the first node to the second node to elicit an acceptance signal therefrom, and reserving a portion of a pool bandwidth resource of the first node;

c) invoking said CAC algorithm to reserve a portion of said free bandwidth resource of the first node;

d) receiving the copy of the reallocation request at said second node, reserving a portion of a pool bandwidth resource of the second node, transmitting said acceptance signal from the second node to said first node, and invoking said CAC algorithm to reserve a portion of said free bandwidth resource of the second node;

e) receiving said acceptance signal at said first node indicating that same amount of said portion reserved by the step (b) is available in said second node, temporarily allocating said portion reserved by the step (b) to said user terminal, and transmitting a confirmation signal from said first node to said second node;

f) permanently allocating the portion of the free bandwidth resource of the first node reserved by the step (c) to the user terminal and restoring the portion of the pool bandwidth resource of the first node temporarily allocated by the step (e); and

g) receiving said confirmation signal at said second node for permanently allocating the portion of the free bandwidth resource of the second node reserved by the step (d) to the user terminal and restoring the portion of the pool bandwidth of the second node reserved by the step(d).

15. A method as claimed in claim 14, further comprising the steps of:

transmitting a deallocation indication from the user terminal when the occupancy of said buffer is lower than a second predefined value;

receiving said deallocation indication at said first node and transmitting a copy of said deallocation indication from the first node to the second node to allow said second node to deallocate part of the allocated resource portions of the second node; and

deallocating part of the resource allocated to the user terminal by the first node.