Dimensioning bandwidth and connection admission control for elastic traffic in high-speed communication networks

• US 6,266,322 B1
• Filed: 06/05/1998
• Issued: 07/24/2001
• Est. Priority Date: 02/12/1998
• Status: Expired due to Term

• Current Assignee: AT&T Corporation (AT&T, Inc.)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Kogan, Yaakov, Berger, Arthur W.
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): JONES, PRENELL P
• Application Number:
  US09/092,422
• Time in Patent Office: 1,145 Days
• Field of Search: 370/229, 370/230-234, 370/395, 370/235-238, 370/255, 370/407, 370/396, 370/252, 379/111-114, 379/220, 379/229
• US Class Current: 370/229
• CPC Class Codes: H04L 2012/5632 Bandwidth allocation
• CPC Class Codes: H04L 41/0896 Bandwidth or capacity management, i.e. automatically increasing or decreasing capacities flow or congestion control using dynamic resource allocation, e.g. in-call renegotiation, H04L47/76
• CPC Class Codes: H04L 47/15 in relation to multipoint traffic arrangements for broadcast or multicast in data networks H04L12/18
• CPC Class Codes: H04L 47/70 Admission control; Resource allocation
• CPC Class Codes: H04L 47/822 Collecting or measuring resource availability data
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections
• CPC Class Codes: H04Q 3/0066 Bandwidth allocation or management

Abstract

A method for dimensioning link bandwidth for elastic-data traffic for a link in a communications network, in which a number of connections N having elastic-data traffic flowing over a bottlenecked link in a communications network is determined. A transfer rate ?f for each connection is determined for the condition that the communications network is not a constraining resource for the connection. A per-connection bandwidth objective b is determined for elastic-data traffic flowing over the link. Lastly, a link bandwidth B for the link is dimensioned for the elastic-data traffic flowing over the link based on either a mean performance criterion or a tail performance criterion using the determined number of connections N, the determined transfer rate for each connection and the determined per-connection bandwidth objective b.

Claims

1. A method for dimensioning link bandwidth for elastic-data traffic for a link in a communications network, the method comprising the steps of:

determining a number of connections N having elastic-data traffic flowing over a link in a communications network;

determining a transfer rate u for each connection for the communications network not being a constraining resource for the connection;

determining a per-connection bandwidth objective b for elastic-data traffic flowing over the link; and

dimensioning a link bandwidth B for the link for the elastic-data traffic flowing over the link based on the determined number of connections N, the determined transfer rate u for each connection and the determined per-connection bandwidth objective b.

2. The method according to claim 1 wherein said link, once dimensioned, is heavily utilized.

3. The method according to claim 1, further comprising the step of determining a closed-queuing network model for the link, and

wherein the step of dimensioning the link bandwidth B for the link is based on the closed-queuing network model for the link.

4. The method according to claim 1, wherein the step of dimensioning the link bandwidth B is based on a mean performance criterion.

5. The method according to claim 1, wherein the step of dimensioning the bandwidth is defined by $B=h·$

N$\mathrm{wherein}$$h={\left(\frac{1}{b}+\frac{1}{u}\right)}^{-1}.$

6. The method according to claim 5, wherein b is between 10³ bits per second and 10⁷ bits per second, inclusive.

7. The method according to claim 5, further comprising the steps of:

determining a maximum number of connections N* allowed on the link based on the link bandwidth B; and

controlling connection admission to the link based on the determined maximum number of connections N*.

8. The method according to claim 1, further comprising the steps of:

determining a maximum number of connections N* allowed on the link based on the link bandwidth B; and

controlling connection admission to the link based on the determined maximum number of connections N*.

9. The method according to claim 8, wherein the step of determining the maximum number of connections N* is defined by:

$N^{*}=B/h,<br><br>\mathrm{where}$$h={\left(\frac{1}{b}+\frac{1}{u}\right)}^{-1}.$

10. The method according to claim 1, wherein the step of dimensioning the link bandwidth B is based on a tail performance criterion.

11. The method according to claim 10, wherein the step of dimensioning the link bandwidth is defined by $B=h·$

[N+γ

+2

γ



 



N+γ

2],

wherein$h={\left(\frac{1}{b}+\frac{1}{u}\right)}^{-1},<br><br>\mathrm{and}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{wherein}$$\mathrm{\gamma <br><br>}=\frac{1}{2}<br><br>q_{\mathrm{\alpha <br><br>}}^2<br><br>h/u=\frac{1}{2}<br><br>\text{\hspace{1em}<br><br>}<br><br>q_{\mathrm{\alpha <br><br>}}^2·<br><br>b/\left(b+u\right),<br><br>\mathrm{such}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{that},<br><br>\sqrt{N}<br><br>u/b><br><br>q_{\mathrm{\alpha <br><br>}},$

wherein q_α

is the (1−

α

)-quantile of the standard normal distribution with mean=0 and variance=1.

12. The method according to claim 11, wherein α

is between 0.01 and 0.1.

13. The method according to claim 11, wherein b is between 10³ bits per second and 10⁷ bits per second, inclusive.

14. The method according to claim 11, further comprising the steps of:

determining a maximum number of connections N* allowed on the link based on the link bandwidth B; and

controlling connection admission to the link based on the determined maximum number of connections N*.

15. The method according to claim 14, wherein the step of determining the maximum number of connections N* is defined by $N^{*}=\mathrm{integer}$

(B/h-qα



B/u),

wherein$h={\left(\frac{1}{b}+\frac{1}{u}\right)}^{-1},$

where the input parameters are such that $\sqrt{\mathrm{Bu}}/b><br><br>q_{\mathrm{\alpha <br><br>}},$

wherein q_α

is the (1−

α

)-quantile of the standard normal distribution with mean=0 and variance=1.

16. The method according to claim 1, wherein the communications network is an ATM network.

17. The method according to claim 16, wherein a connection uses an Available Bit Rate transfer capability.

18. The method according to claim 16, wherein a connection uses an Unspecified Bit Rate transfer capability.

19. The method according to claim 1, wherein the communications network uses a Transmission Control Protocol for sending the elastic-data traffic over the link.

20. The method according to claim 1, wherein the communications network uses a Transmission Control Protocol over an Internet Protocol for sending the elastic-data traffic over the link.

21. The method according to claim 1, wherein the communications network uses a Transmission Control Protocol over an Internet Protocol and the Internet Protocol is over an Asynchronous Transfer Mode protocol for sending the elastic-data traffic over the link.

22. A method for dimensioning link bandwidth for elastic-data traffic for a link in a communications network, the method comprising the steps of:

determining a closed-queuing network model for the communication network, the closed-queuing network model having a predetermined number N of connections, and

dimensioning the link bandwidth B for the link based on the closed-queuing network model.