Method for assessing and monitoring the performance of one or more packet synchronization services in a packet data transmission network, (a) the packet data transmission network comprising (i) a transport network for receiving, from a central time information distribution node, a digital timing signal (S p) including a central time information for at least one of the timing parameters absolute time, relative time, frequency and phase, and (ii) at least one receiving network node for receiving the digital timing signal (S p) via the transport network, detecting the central time information included in the digital timing signal (S p) received and using the central time information in order to synchronize the at least one timing parameter at the receiving network node and the central time information distribution node; characterized by the steps of: (b) at a packet data transmission network probing point, (i) determining at least two synchronization quality describing or influencing parameters based on at least one of the digital timing signal (S p) received, the recovered time information for the at least one timing parameter and parameters having impact on the synchronization quality and describing or controlling properties of hardware components present at the receiving network node; (ii) determining, for a given time interval, values of at least three synchronization performance scores based on the at least two synchronization quality describing or influencing parameters; and (iii) collecting the values of the at least three synchronization performance scores for one or more given collection time intervals and storing and/or displaying these synchronization performance score values for monitoring purposes; (c) wherein the at least three synchronization performance scores comprise a clock recovery score and a phase recovery score and at least one of a network usability score in forward direction from the central time information distribution node to the network probing point and a network usability score in reverse direction from the network probing point to the central time information distribution node. (a) the packet data transmission network comprising (i) a transport network for receiving, from a central time information distribution node, a digital timing signal (S p) including a central time information for at least one of the timing parameters absolute time, relative time, frequency and phase, and (ii) at least one receiving network node for receiving the digital timing signal (S p) via the transport network, detecting the central time information included in the digital timing signal (S p) received and using the central time information in order to synchronize the at least one timing parameter at the receiving network node and the central time information distribution node; (i) a transport network for receiving, from a central time information distribution node, a digital timing signal (S p) including a central time information for at least one of the timing parameters absolute time, relative time, frequency and phase, and (ii) at least one receiving network node for receiving the digital timing signal (S p) via the transport network, detecting the central time information included in the digital timing signal (S p) received and using the central time information in order to synchronize the at least one timing parameter at the receiving network node and the central time information distribution node; (b) at a packet data transmission network probing point, (i) determining at least two synchronization quality describing or influencing parameters based on at least one of the digital timing signal (S p) received, the recovered time information for the at least one timing parameter and parameters having impact on the synchronization quality and describing or controlling properties of hardware components present at the receiving network node; (ii) determining, for a given time interval, values of at least three synchronization performance scores based on the at least two synchronization quality describing or influencing parameters; and (iii) collecting the values of the at least three synchronization performance scores for one or more given collection time intervals and storing and/or displaying these synchronization performance score values for monitoring purposes; (i) determining at least two synchronization quality describing or influencing parameters based on at least one of the digital timing signal (S p) received, the recovered time information for the at least one timing parameter and parameters having impact on the synchronization quality and describing or controlling properties of hardware components present at the receiving network node; (ii) determining, for a given time interval, values of at least three synchronization performance scores based on the at least two synchronization quality describing or influencing parameters; and (iii) collecting the values of the at least three synchronization performance scores for one or more given collection time intervals and storing and/or displaying these synchronization performance score values for monitoring purposes; (c) wherein the at least three synchronization performance scores comprise a clock recovery score and a phase recovery score and at least one of a network usability score in forward direction from the central time information distribution node to the network probing point and a network usability score in reverse direction from the network probing point to the central time information distribution node.