This Agreement may not be terminated, amended, supplemented, waived or modified, except by an instrument in writing signed by WEST and the Administrative Agent with notice to the Indenture Trustee and the Security Trustee;   provided that WEST may only terminate, amend, supplement, waive or modify this Agreement in accordance with Section 5.02(a) of the Indenture; provided further that no amendment, supplement, waiver or modification which affects the Indenture Trustee’s or Security Trustee’s rights, duties, indemnities or immunities hereunder may be made without the express written consent of the Indenture Trustee or Security Trustee, respectively.  No failure or delay of any party in exercising any power or right thereunder shall operate as a waiver thereof, nor shall any single or partial exercise of any such right or power, or any abandonment or discontinuance of steps to enforce such a right or power, preclude any other or further exercise thereof or the exercise of any other right or power.