Method of ensuring that each node of a private telecommunication network is synchronized to the best available clock at all times

A method of synchronizing nodes of a private telecommunication network to best available clock signals at all times, wherein said private telecommunication network comprises a plurality of nodes which transmit at least synchronization information to each other via point-to-point digital transmission links, each node of said private telecommunication network comprising means for storing node characteristic data comprising information indicating available clock signals, respective quality levels of said available clock signals, and potential supply information indicating whether a node is adapted to supply clock signals, and means for selecting a best available clock signal based upon said node characteristic data and said synchronization information exchanged between nodes when a loss of previously received clock signals is detected, said nodes being synchronized by clock signals supplied by one of said point-to-point digital transmission links, said method comprising the steps of:

• preselecting, for each node directly connected to at least two point-to-point digital transmission links, at least two point-to-point digital transmission link ports, one being designated a master clock port and the other being designated a backup clock port, wherein nodes comprising said at least two point-to-point digital transmission link ports form a synchronization tree of said private telecommunication network;
• preselecting said nodes comprising said at least two point-to-point digital transmission link ports as potential supplier nodes for potentially supplying said clock signals to nodes which are directly connected to said potential supplier nodes via a point-to-point digital transmission link, wherein said nodes comprising said at least two point-to-point digital transmission link ports are assigned potential supply information;
• storing said potential supply information as one of said node characteristic data;
• detecting a loss of said previously received clock signals by at least one of said nodes;
• initiating an exchange of said synchronization information between said at least one of said nodes detecting said loss of said previously received clock signals and each node directly connected to said at least one of said nodes via a corresponding point-to-point digital transmission link, wherein each exchange of said synchronization information corresponds to a synchronization proposal which is one of:
• (a) from said at least one of said nodes having detected said loss of said previously received clock signals to one of said nodes directly connected to said at least one of said nodes, and (b) one node having received said synchronization proposal to another node with which said one node is directly connected via a point-to-point digital transmission link;
• and
• determining, for said at least one of said nodes detecting said loss of said previously received clock signals and for each of said nodes receiving said synchronization proposal, a best available clock signal for synchronization based upon said synchronization information transmitted and received during said exchange step.