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EP-4599532-B1 - SYSTEM AND METHOD TO DISCOVER CANDIDATE PTP CLOCK SOURCE(S) OVER IP/MPLS NETWORK

EP4599532B1EP 4599532 B1EP4599532 B1EP 4599532B1EP-4599532-B1

Inventors

  • SRIVASTAVA, SHARAD KUMAR
  • GARG, VINEET KUMAR
  • SINGH, Krishan
  • CHAUHAN, Vijendra States

Dates

Publication Date
20260513
Application Date
20241121

Claims (13)

  1. A device, comprising: a processing system including a processor; a clock; and a memory that stores executable instructions that, when executed by the processing system, cause the processing system to perform operations comprising: advertising a capability as a precision timing protocol, PTP, master clock through an Internet Protocol, IP, network, wherein the advertising includes an IP address of the device, wherein the advertising is provided to a first area that includes a first group of nodes comprising the PTP client node and wherein the advertising is not provided to a second area that includes a second group of nodes that does not include the PTP client node; receiving a unicast signaling request from the PTP client node in the network; and sending clock messages to the PTP client node responsive to granting the unicast signaling request from the PTP client node.
  2. The device of claim 1, wherein the device further comprises a receiver configured to receive time information from a time source and wherein the operations further comprise synchronizing the clock to the time source.
  3. The device of claim 1, wherein the advertising is performed via an Interior Gateway Protocol, IGP.
  4. The device of claim 3, wherein the device operates as an area border router and locks to candidate master clock nodes in a particular area while advertising as a master clock node for an adjacent area being served.
  5. The device of claim 4, wherein the advertising uses a new link state protocol, LSP, data unit.
  6. The device of claim 3, wherein the IGP is an Open Shortest Path First.
  7. The device of claim 6, wherein the advertising uses an opaque Link State Advertisement, LSA.
  8. The device of claim 7, wherein the advertising stays within an Open Shortest Path First, OSPF area of the device.
  9. A method comprising: advertising, by a processing system including a processor of a device, a capability as a precision timing protocol, PTP, master clock through an Internet Protocol, IP, network, wherein the advertising includes an IP address of the device, wherein the advertising is provided to a first area that includes a first group of nodes comprising the PTP client node and wherein the advertising is not provided to a second area that includes a second group of nodes that does not include the PTP client node; receiving, by the processing system, a unicast signaling request from a PTP client node in the network; and sending, by the processing system, clock messages to the PTP client node responsive to granting the unicast signaling request from the PTP client node.
  10. The method of claim 9, comprising receiving time information from a time source and synchronizing the PTP master clock to the time source.
  11. The method of claim 9, wherein the advertising is performed via an Interior Gateway Protocol, IGP.
  12. The method of claim 11, wherein the device operates as an area border router and locks to candidate master clock nodes in a particular area while advertising as a master clock node for an adjacent area being served.
  13. The method of claim 12, wherein the advertising uses a new link state protocol, LSP, data unit.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S) The present application claims priority to U.S. Patent Application Serial No. 18/419,810, filed January 23, 2024, which claims priority under 35 U.S.C. §1.119 to Indian patent application no. 202311081663, filed on November 30, 2023. FIELD OF THE DISCLOSURE The subject disclosure relates to a system and method to discover candidate precision timing protocol (PTP) master clock sources over an Internet Protocol (IP)/multi-protocol label switching (MPLS) network. BACKGROUND PTP has become critical to deliver synchronization of radios in modern cellular networks, such as fifth generation (5G) networks. 5G networks have been rapidly evolving into a fully automated network. Today a network administrator needs to manually provision an IP address for a candidate master clock to enable PTP synchronization of node over IP. Furthermore, the administrator must manually provision such IP address(es) whenever a list of potential master clock changes. EP 2 782 290 A1 describes a method, system and apparatus for implementing hybrid networking of multiple clock synchronization technologies. US 2023/057463 A1 describes network timing topology discovery and visualization using interior gateway protocols. US 2012/069943 describes a SCAN-REQ/RSP message exchange process comprising a Master GPS Locked Advertisement Message and a Master Holdover Advertisement Message transmitted by a master. BRIEF DESCRIPTION OF THE DRAWINGS Reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein: FIG. 1 is a block diagram illustrating an exemplary, non-limiting embodiment of precision time protocol nodes in a network in accordance with various aspects described herein.FIG. 2 is a block diagram illustrating an exemplary, non-limiting embodiment of precision time protocol nodes in an OSPF network in accordance with various aspects described herein. Reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein: FIG. 1 is a block diagram illustrating an exemplary, non-limiting embodiment of precision time protocol nodes in a network in accordance with various aspects described herein.FIG. 2 is a block diagram illustrating an exemplary, non-limiting embodiment of precision time protocol nodes in an OSPF network in accordance with various aspects described herein.FIG. 3 depicts an illustrative embodiment of a method performed by a node in an IP network in accordance with various aspects described herein.FIG. 4 is a block diagram of an example, non-limiting embodiment of a computing environment in accordance with various aspects described herein. DETAILED DESCRIPTION The subject disclosure describes, among other things, illustrative embodiments for a precision time protocol master clock advertising its capabilities over Internet Protocol networks. Other embodiments are described in the subject disclosure. One embodiments includes a device according to appended clainm 1. One or more aspects of the subject disclosure, not part of the scope of the invention, include a device, having: a processing system including a processor; a clock; and a memory that stores executable instructions that, when executed by the processing system, facilitate performance of operations, the operations comprising: identifying a first precision timing protocol (PTP) master clock through a message received in an Internet Protocol (IP) network; registering as a PTP client node with the first PTP master clock through a unicast signaling mechanism; advertising a capability as a second PTP master clock through the IP network, wherein the advertising includes an IP address of the device; receiving a second unicast signaling mechanism from a second PTP client node in the IP network; and sending first clock messages to the PTP client node responsive to accepting the second PTP client node. One or more aspects of the subject disclosure, not part of the scope of the invention, include a non-transitory. machine-readable medium, comprising executable instructions that, when executed by a processing system including a processor, facilitate performance of operations, the operations including: identifying a first precision timing protocol (PTP) master clock from a message received in an Internet Protocol (IP) network; registering as a first PTP client node with the first PTP master clock; synchronizing a clock with first clock messages received from the first PTP master clock; advertising a capability as a second PTP master clock through the IP network; receiving a request from a second node in the IP network to become a second PTP client node; and sending second clock messages to the second PTP client node responsive to accepting the second PTP client node. ITU-T has defined two telecommunications standards, namely G.8265.1 and G.8275.2, for the frequency recovery and phase recovery, respectively, in IP networks. These standards propose a unicast di