Method for reserving capacity on a communication network link

1. A computer-implemented method for reserving capacity on a communication network link for at least a guaranteed bit rate traffic and a best effort traffic, the method comprising:

determining a dimensioned capacity DGBR for the guaranteed bit rate traffic based at least on an expected guaranteed bit rate traffic load and a grade of service;

determining a dimensioned capacity DTOT for the total traffic based at least on DGBR, an expected best effort traffic load, and the grade of service;

determining a reserved capacity RTOT for the total traffic by selecting a minimum amongst capacities available on the communication network link that exceed DTOT;

determining a reserved capacity RGBR for the guaranteed bit rate traffic based at least on DGBR, DTOT, and RTOT;

reserving RTOT as capacity for a higher-level pipe on the communication network link;

reserving RGBR as capacity for a first lower-level pipe for the guaranteed bit rate traffic within the higher-level pipe; and

reserving RTOT as capacity for a second lower-level pipe for the best effort traffic within the higher-level pipe.

2. The method of claim 1 wherein a label switched path is a sequence of routers configured for routing packets each including at least one label, a label of a packet is an identifier physically contiguous to the packet and identifying a forwarding equivalence class to which the packet belongs, and a forwarding equivalence class is a group of packets that are forwarded in the same manner, wherein:

the higher-level pipe is a higher-level label switched path;

the first lower-level pipe is a first lower-level label switched path for guaranteed bit rate traffic; and

the second lower-level pipe is a second lower-level label switched path for best effort traffic.

3. The method of claim 1 wherein:

the higher-level pipe is an aggregated Differentiated Services (DiffServ) pipe;

the first lower-level pipe is a DiffServ pipe for guaranteed bit rate traffic within the aggregated DiffServ pipe; and

the second lower-level pipe is a DiffServ pipe for best effort traffic within the aggregated DiffServ pipe.

4. The method of claim 1 wherein the determining RGBR includes computing RGBR based on the formula

RGBR=α·RTOT·DGBR/DTOT,

where α=IGBR/IBE, where IGBR is the expected increase of the guaranteed bit rate traffic over a given period and IBE is the expected increase of the best effort traffic over the given period.

5. The method of claim 1 further comprising:

setting up the higher-level pipe before the reserving RTOT as capacity for the higher-level pipe;

setting up the first lower-level pipe before the reserving RGBR as capacity for the first lower-level pipe;

setting up the second lower-level pipe before the reserving RTOT as capacity for the second lower-level pipe.

6. The method of claim 1 wherein the method is carried out for reserving capacity on the communication network link at one point in time.

7. The method of claim 1 wherein the method is carried out repeatedly for reserving capacity on the communication network link during a period of time.

8. The method of claim 1 wherein the grade of service includes a maximum blocking probability.

9. The method of claim 1 wherein the determining DGBR is further based on at least one quality-of-service parameter.

10. The method of claim 9 wherein the at least one quality-of-service parameter includes at least one of a maximum packet delay and a maximum loss requirement.

11. The method of claim 1 wherein the method is carried out for reserving capacity on the communication network link by reserving the capacity in a network node at one edge of the communication network link.

12. A computer program product stored in a non-transitory computer readable medium for controlling a computer so as to reserve capacity on a communication network link for at least a guaranteed bit rate traffic and a best effort traffic, the computer program product comprising software instructions which, when run on the computer, causes the computer to:

determine a dimensioned capacity (DGBR) for the guaranteed bit rate traffic based at least on an expected guaranteed bit rate traffic load and a grade of service;

determine a dimensioned capacity (DTOT) for the total traffic based at least on DGBR, an expected best effort traffic load, and the grade of service;

determine a reserved capacity (RIOT) for the total traffic by selecting a minimum amongst capacities available on the communication network link that exceed DTOT;

determine a reserved capacity (RGBR) for the guaranteed bit rate traffic based at least on DGBR, DTOT, and RIOT;

reserve RIOT as capacity for a higher-level pipe on the communication network link;

reserve RGBR as capacity for a first lower-level pipe for the guaranteed bit rate traffic within the higher-level pipe; and

reserve RTOT as capacity for a second lower-level pipe for the best effort traffic within the higher-level pipe.

13. A controller configured to reserve capacity on a communication network link for at least a guaranteed bit rate traffic and a best effort traffic, the controller comprising:

a first determiner configured to determine a dimensioned capacity DGBR for the guaranteed bit rate traffic based at least on an expected guaranteed bit rate traffic load and a grade of service;

a second determiner configured to determine a dimensioned capacity DTOT for the total traffic based at least on DGBR, an expected best effort traffic load, and the grade of service;

a third determiner configured to determine a reserved capacity RTOT for the total traffic by selecting a minimum amongst capacities available on the communication network link that exceed DTOT;

a fourth determiner configured to determine a reserved capacity RGBR for the guaranteed bit rate traffic based at least on DGBR, DTOT, and RTOT;

a first reserver configured to reserve RTOT as capacity for a higher-level pipe on the communication network link;

a second reserver configured to reserve RGBR as capacity for a first lower-level pipe for the guaranteed bit rate traffic within the higher-level pipe;

a third reserver configured to reserve RTOT as capacity for a second lower-level pipe for the best effort traffic within the higher-level pipe.

14. A network node configured to handle at least three label switched paths, wherein a label switched path is a sequence of routers configured for routing packets each including at least one label, a label of a packet is an identifier physically contiguous to the packet and identifying a forwarding equivalence class to which the packet belongs, and a forwarding equivalence class is a group of packets that are forwarded in the same manner:

wherein the at least three label switched paths comprise:

a higher-level label switched path with a reserved capacity of RTOT;

a first lower-level label switched path for guaranteed bit rate traffic within the higher-level label switched path with a reserved capacity of RGBR;

a second lower-level label switched path for best effort traffic within the higher-level label switched path with a reserved capacity of RIOT;

wherein:

reserved capacity RTOT is a minimum amongst capacities available on a communication network link that exceed a dimensioned capacity DTOT;

reserved capacity RGBR is based at least on a dimensioned capacity DGBR, dimensioned capacity DTOT, and reserved capacity RTOT;

dimensioned capacity DGBR is based at least on an expected guaranteed bit rate traffic load and a grade of service; and

dimensioned capacity DTOT is based at least on DGBR, an expected best effort traffic load, and the grade of service.

15. A network node configured to handle at least three Differentiated Services (DiffServ) pipes:

wherein the at least three DiffServ pipes comprise:

one higher-level pipe being an aggregated DiffServ pipe with a reserved capacity of RTOT;

one first lower-level pipe being a DiffServ pipe for guaranteed bit rate traffic within the aggregated DiffServ pipe with a reserved capacity of RGBR; and

one second lower-level pipe being a DiffServ pipe for best effort traffic within the aggregated DiffServ pipe with a reserved capacity of RIOT;

wherein:

reserved capacity RIOT is a minimum amongst capacities available on a communication network link that exceed a dimensioned capacity DTOT;

reserved capacity RGBR is based at least on a dimensioned capacity DGBR, dimensioned capacity DTOT and reserved capacity RTOT;

dimensioned capacity DGBR is based at least on an expected guaranteed bit rate traffic load, and a grade of service; and

dimensioned capacity DTOT is based at least on DGBR, an expected best effort traffic load, and the grade of service.