System and method for providing traffic flow control in a communication network

1. A system for establishing a data transmission rate in a telephony communication network for data transmission from a distribution network in a central office (CO), said distribution network including a first communication module coupled to a remote network unit including a second communication module, said second communication module being connected to the distribution network by a high-capacity transmission link, and said second communication module comprising digital subscriber link (DSL) ports connected via at least one local loop to a plurality of user terminals, the system comprising:

a first storage device for storing a predetermined rate limit for transmission of data by the second communication module, the first storage device being associated with the first communication module;

a traffic shaping unit at the first communication module for establishing a first module data transmission rate in dependence upon the predetermined rate limit to enable the second communication module to transmit data therefrom within the predetermined rate limit;

a second storage device associated with the second communication module for storing the predetermined rate limit;

a communication submodule in the second communication module to extract the predetermined rate limit from the second storage device and transmit the predetermined rate limit to the first communication module,

wherein said predetermined rate limit for transmission of data by the second communication module, which is stored in the first storage device associated with the first communication module, is based on at least one of transmission rates of said DSL ports in said second communication module and transmission rates of said user terminals, and

wherein the predetermined rate limit is dependent upon factors including distances of the user terminals from the remote network unit, transmission rates of DSL devices in the user terminals, and levels of service subscribed to by users of the user terminals.

2. The system recited in claim 1 , wherein the first communication module is configured to receive from the distribution network data directed to the second communication module, and the first communication module includes, at an interface to the distribution network, a data buffer for buffering the data directed to the second communication module.

3. The system recited in claim 2 , wherein the predetermined rate limit is a rate at which the data directed to the second communication module is extracted from the data buffer by the traffic shaping unit.

4. The system recited in claim 2 , wherein the data buffer at the interface is a FIFO queue and the traffic shaping unit is configured to back pressure at the FIFO queue any flow of data directed to the second communication module which exceeds the predetermined rate limit established by the traffic shaping unit.

5. The system recited in claim 1 , wherein the predetermined rate limit comprises a train rate established for the DSL ports in said second communication module.

6. The system recited in claim 1 , wherein the predetermined rate limit comprises a train rate of a data port in one of said user terminals to which said data is being transmitted from the distribution network to said one of said user terminals via said first communication module, said high-capacity transmission link, said second communication module, and said at least one local loop.

7. A system for establishing a data transmission rate in a telephony communication network from a first communication module to a second communication module, said second communication module being connected to the first communication module by a first transmission link, said second communication module being connected via at least one local loop to a plurality of user terminals, and said first transmission link having a higher data transmission capacity than said at least one local loop, the system comprising:

a first storage device for storing a predetermined rate limit for transmission of data by the second communication module, the first storage device being associated with the first communication module;

a traffic shaping unit at the first communication module for establishing a first module data transmission rate in dependence upon the predetermined rate limit to enable the second communication module to transmit data therefrom within the predetermined rate limit;

a second storage device associated with the second communication module for storing the predetermined rate limit;

a communication submodule in the second communication module to extract the predetermined rate limit from the second storage device and transmit the predetermined rate limit to the first communication module,

wherein said predetermined rate limit for transmission of data by the second communication module, which is stored in the first storage device associated with the first communication module, is based on rates of data transmission between said second communication module and said user terminals, and

wherein the predetermined rate limit is dependent upon factors including distances of the user terminals from the remote network unit, transmission rates of DSL devices in the user terminals, and levels of service subscribed to by users of the user terminals.

8. The system recited in claim 7 , wherein the first communication module is configured to receive from a data distribution network data directed to the second communication module, and the first communication module includes, at an interface to the data distribution network, a data buffer for buffering the data directed to the second communication module.

9. The system recited in claim 8 , wherein the predetermined rate limit is a rate at which the data directed to the second communication module is extracted from the data buffer by the traffic shaping unit.

10. The system recited in claim 9 , wherein the data buffer at the interface is a FIFO queue and the traffic shaping unit is configured to back pressure at the FIFO queue any flow of data directed to the second communication module which exceeds the predetermined rate limit established by the traffic shaping unit.

11. The system recited in claim 9 , wherein the predetermined rate limit comprises a train rate established for DSL ports in said second communication module.