Method and system for enabling connection of a call

1. A method for connecting a call across an Asynchronous Transfer Mode-Multiprotocol Label Switching (ATM-MPLS) network of network elements as a communication path for the call is being set up, the call comprising an encapsulation mode parameter for which a particular value must be assigned for each MPLS segment of the communication path between adjacent network elements, at least one network element supporting multiple values for the encapsulation mode parameter, the method comprising:

receiving at a network element on the communication path an indicator that network elements along the communication path of the call are required to use a predetermined value for the encapsulation mode parameter when susceptibility to clipping is enabled for the call; and

establishing a connection to an adjacent network element on the communication path using the predetermined value for the encapsulation mode parameter, prior to setting up a next MPLS segment of the communication path.

2. The method of claim 1 , wherein establishing a connection is performed irrespective of confirmation that the adjacent network element supports the predetermined value for the parameter.

3. The method of claim 1 , further comprising:

detecting the indicator; and

in response to detecting the indicator, selecting the particular value for the parameter.

4. The method of claim 1 , further comprising:

conveying the indicator to a subsequent network element.

5. A network element configured to implement the method of claim 1 .

6. A computer readable medium having computer readable instructions stored thereon that when executed implement the method of claim 1 .

7. A method for connecting a call across an Asynchronous Transfer Mode-Multiprotocol Label Switching (ATM-MPLS) network of network elements as a path for the call is being set up, the call comprising an encapsulation mode parameter for which a value must be assigned for each MPLS segment of the path between adjacent network elements, at least one network element supporting multiple values for the encapsulation mode parameter, the method comprising:

determining that a particular value for the encapsulation mode parameter is to be used for the call; and

sending an indicator to a network element on the path, the indicator indicating that the particular value is to be used when susceptibility to clipping is enabled for the call, the network element configured to use the particular value for the encapsulation mode parameter in response receiving the indicator and to connect to an adjacent network element on the path, prior to setting up a next MPLS segment of the path.

8. The method of claim 7 , further comprising:

determining the particular value to be used.

9. The method of claim 8 , further comprising:

selecting a most efficient encapsulation mode for the call from a plurality of encapsulation modes available for the ATM-MPLS network.

10. The method of claim 7 , further comprising:

configuring the network element to use the particular value for the encapsulation mode parameter in response to detecting the indicator.

11. The method of claim 7 , further comprising:

selecting the particular value for the encapsulation mode from the group consisting of: 1:1 cell mode; N:1 cell mode; SDU frame mode; and PDU frame mode.

12. The method of claim 7 , wherein support of the particular value is mandatory for all of the network elements in the ATM-MPLS network.

13. A computer readable medium having computer readable instructions stored thereon that when executed implement the method of claim 7 .

14. A system for enabling connection of a call across an Asynchronous Transfer Mode-Multiprotocol Label Switching (ATM-MPLS) network of network elements as a path for the call is being set up, the call comprising an encapsulation mode parameter for which a value must be assigned for each MPLS segment of the path between adjacent network elements, at least one network element supporting multiple values for the encapsulation mode parameter, the system comprising:

a module for creating a setup message for the call, the setup message containing a indicator that a particular value for the encapsulation mode parameter is to be used when susceptibility to clipping is enabled for the call; and

an interface for sending the setup message to a network element on the path, the network element configured to use the particular value for the encapsulation mode parameter in response to detecting the indicator and to connect to an adjacent network element, prior to setting up a next MPLS segment of the path.

15. The system of claim 14 , further comprising:

a module for determining the particular value to be used.

16. The system of claim 15 , wherein the module for determining the particular value comprises:

a list of values that can be selected;

means for determining a most efficient value from the list; and

means for selecting the most efficient value.

17. The system of claim 14 , further comprising:

means for configuring at least one of the network elements to use the particular value if the at least one network element detects the indicator.