An Admission Control Node and a method performed thereby for enabling a measurement between a first and a second device in a communication network, and a first device and a method performed thereby for performing the measurement between the first device and the second device in a communication network are provided. The method in the Admission Control Node comprises receiving, from the first device, a request for performing the measurement between the first and the second device and, determining segments comprised in a path between the first and the second device. The method also comprises determining a current measurement situation for the segments, and deciding to allow or reject the request for performing the measurement based on the current measurement situation for the segments. The method further comprises informing the first device about the decision of allowing or rejecting the request for performing the measurement.