The base station of the Gigaset CL660 is an analogue landline telephone, which means that it is compatible with an analogue telephone connection. The Connect Box 3 Fiber from Sunrise offers a telephone connection that usually works analogue or via VoIP (Voice over Internet Protocol). If the Connect Box offers an analogue connection, the base station of the Gigaset CL660 should be compatible. However, it is advisable to check the exact connection options of the Connect Box to ensure that it works with an analogue telephone.
