Abstract: A clock tracing method includes: determining a shortest path to each source network element, and selecting a best source network element among all the source network elements; determining a shortest path to the best source network element according to the shortest path, using the shortest path to the best source network element as a clock tracing path if the shortest path to the best source network element is different from an old clock tracing path and a traceable message is received, and using the clock tracing path for tracing clocks; and using the old clock tracing path for tracing clocks if the shortest path to the best source network element is the same as the old clock tracing path or no traceable message is received. A clock tracing apparatus and a network element are also provided. The provided clock tracing method, apparatus and network element may ensure high-quality clock transmission, and the fast performance of automatic clock tracing.

Abstract: A method for implementing distribution of link state information in an optical network includes: determining information of each link protection attribute section included in a Traffic Engineering (TE) link; carrying the information of each link protection attribute section in a customized TLV, respectively; distributing the TLV in the optical network via Traffic Engineering Link State Advertisement (TE LSA). With this invention, all the link state information such as multiple kinds of protection types included in one TE link can be carried in the customized TLV to distribute. Therefore, in the implementation of this invention, one TE link corresponding to one optical fiber can be configured with multiple kinds of protection types.

Abstract: A method for establishing clock tracing relations and an apparatus for computing clock tracing relations are disclosed. The method includes: computing a Shortest Path Tree (SPT) from a clock source access node to other nodes in a network; selecting nodes governed by the clock source access node according to the SPT and the source information corresponding to the SPT; and establishing clock tracing relations from the clock source access node to the governed node consecutively along the SPT. The apparatus for computing clock tracing relations includes: a path computing unit, a source selecting unit, and a path issuing unit.

Abstract: A method for implementing distribution of link state information in an optical network includes: determining information of each link protection attribute section included in a Traffic Engineering (TE) link; carrying the information of each link protection attribute section in a customized TLV, respectively; distributing the TLV in the optical network via Traffic Engineering Link State Advertisement (TE LSA). With this invention, all the link state information such as multiple kinds of protection types included in one TE link can be carried in the customized TLV to distribute. Therefore, in the implementation of this invention, one TE link corresponding to one optical fiber can be configured with multiple kinds of protection types.

Abstract: A method for implementing distribution of link state information in an optical network includes: determining information of each link protection attribute section included in a Traffic Engineering (TE) link; carrying the information of each link protection attribute section in a customized TLV, respectively; distributing the TLV in the optical network via Traffic Engineering Link State Advertisement (TE LSA). With this invention, all the link state information such as multiple kinds of protection types included in one TE link can be carried in the customized TLV to distribute. Therefore, in the implementation of this invention, one TE link corresponding to one optical fiber can be configured with multiple kinds of protection types.

Abstract: A clock tracing method includes: determining a shortest path to each source network element, and selecting a best source network element among all the source network elements; determining a shortest path to the best source network element according to the shortest path, using the shortest path to the best source network element as a clock tracing path if the shortest path to the best source network element is different from an old clock tracing path and a traceable message is received, and using the clock tracing path for tracing clocks; and using the old clock tracing path for tracing clocks if the shortest path to the best source network element is the same as the old clock tracing path or no traceable message is received. A clock tracing apparatus and a network element are also provided. The provided clock tracing method, apparatus and network element may ensure high-quality clock transmission, and the fast performance of automatic clock tracing.

Abstract: A method for implementing distribution of link state information in an optical network includes: determining information of each link protection attribute section included in a Traffic Engineering (TE) link; carrying the information of each link protection attribute section in a customized TLV, respectively; distributing the TLV in the optical network via Traffic Engineering Link State Advertisement (TE LSA). With this invention, all the link state information such as multiple kinds of protection types included in one TE link can be carried in the customized TLV to distribute. Therefore, in the implementation of this invention, one TE link corresponding to one optical fiber can be configured with multiple kinds of protection types.