Coordinated timing network configuration parameter update procedure

• US 7,899,894 B2
• Filed: 08/30/2006
• Issued: 03/01/2011
• Est. Priority Date: 08/30/2006
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Kurdt, Georgette, Whitney, David E., Elko, David A., Hack, Michel H. T., Dahlen, Dennis J., Crabtree, Donald, Sevigny, Denise M., Carlson, Scott M., Dhondy, Noshir R., Smith, Ronald M. Sr., Wierbowski, Judith A.
• Primary Examiner(s): Flynn; Nathan
• Assistant Examiner(s): PATEL, CHIRAG R
• Application Number:
  US11/468,352
• Publication Number:
  US 20080059655A1
• Time in Patent Office: 1,644 Days
• Field of Search: 714/12, 713/400, 713/375, 713/500, 713/503, 713/600, 713/401, 709/223
• US Class Current: 709/223
• CPC Class Codes: H04J 3/0667 Bidirectional timestamps, e.g. NTP or PTP for compensation of clock drift and for compensation of propagation delays arrangements for monitoring round trip delays in packet switching networks H04L43/0864
• CPC Class Codes: H04J 3/14 Monitoring arrangements for SDH/SONET rings H04J3/085

Abstract

In a networked data processing system, the updating of timing parameters is carried out via a process in which the detection of the loss of communications with the network is not immediately employed as an indication of parameter invalidity but rather the process employs a system specific delay which permits actions such as server or link recovery to occur without necessitating the declaration of timing parameter invalidity.

Claims

1. A computer program product for updating parameters in a coordinated timing network, the computer program product comprising:

a non-transitory computer readable medium readable by a processor and storing instructions for execution by the processor for performing a method comprising;

receiving by a server of a coordinated timing network identified by a coordinated timing network identifier an information response packet that includes at least one parameter to be changed at the server and specifies a time at which the at least one parameter is to be changed, the at least one parameter being associated with the coordinated timing network, the coordinated timing network comprising a plurality of servers that are time synchronized and receive timing information from a stratum-1 server of the coordinated timing network;

responsive to receiving the information response packet, determining at the server whether the server is in communication with a clock source;

in response to the determining producing a negative result, waiting for a predetermined time to address a temporary loss of communication with the clock source and then determining whether the server is in communication with the clock source, wherein in response to the determining still providing a negative result, declaring one or more parameters at the server to be invalid and not changing the at least one parameter at the specified time; and

responsive to the determining indicating that the server is in communication with the clock source, changing the at least one parameter at the time at which the at least one parameter is to be changed.

2. The computer program product of claim 1, wherein the at least one parameter comprises at least one of a coordinated timing network identifier, a leap seconds offset value, a time zone offset, primary reference time information, coordinated timing network configuration information, and a daylight savings time offset.

3. The computer program product of claim 2, wherein the information response packet is in one format of a plurality of formats depending on the at least one parameter to be updated, the plurality of formats including a first format used in response to an update of the leap seconds offset value or the primary reference time information, a second format used in response to an update of the coordinated timing network identifier or the coordinated timing network configuration information, and a third format used in response to an update of the time zone offset or the daylight savings time offset.

4. The computer program product of claim 1, wherein the declaration of invalidity with respect to the one or more parameters takes place throughout said network.

5. The computer program product of claim 1, wherein the method further includes using one or more current parameters upon condition that said determining produces a positive result.

6. The computer program product of claim 1, wherein, in response to declaring the one or more parameters invalid, the method further includes requesting updated values.

7. The computer program product of claim 1, wherein the predetermined time is the maximum freewheel interval for said server performing the determining, said maximum freewheel interval being based on a maximum skew rate.

8. The computer program product of claim 1, wherein the predetermined time is the maximum freewheel interval for any server in said network, said maximum freewheel interval being based on a maximum skew rate.

9. The computer program product of claim 1, wherein the server receiving the information response packet has a same coordinated timing network identifier as a transmitting server of the information response packet.

10. The computer program product of claim 1, wherein the information response packet is transmitted, in response to detecting the at least one parameter has changed at another server, wherein the detecting uses a parameter key field of an information response packet to determine the at least one parameter has changed.

11. A computer system for updating parameters in a coordinated timing network, the computer system comprising:

a memory; and

a processor in communications with the memory, wherein the computer system is configured to perform a method, the method comprising;

receiving by a server of a coordinated timing network identified by a coordinated timing network identifier an information response packet that includes at least one parameter to be changed at the server and specifies a time at which the at least one parameter is to be changed, the at least one parameter being associated with the coordinated timing network, the coordinated timing network comprising a plurality of servers that are time synchronized and receive timing information from a stratum-1 server of the coordinated timing network;

responsive to the receiving, determining at the server whether the server is in communication with a clock source;

in response to the determining producing a negative result, waiting for a predetermined time to address a temporary loss of communication with the clock source and then determining whether the server is in communication with the clock source, wherein in response to the determining still providing a negative result, declaring one or more parameters at the server to be invalid and not changing the at least one parameter at the specified time; and

responsive to the determining indicating that the server is in communication with the clock source, changing the at least one parameter at the time at which the at least one parameter is to be changed.

12. The computer system of claim 11, wherein the at least one parameter comprises at least one of a coordinated timing network identifier, a leap seconds offset value, a time zone offset, primary reference time information, coordinated timing network configuration information, and a daylight savings time offset.

13. The computer system of claim 12, wherein the information response packet is in one format of a plurality of formats depending on the at least one parameter to be updated, the plurality of formats including a first format used in response to an update of the leap seconds offset value or the primary reference time information, a second format used in response to an update of the coordinated timing network identifier or the coordinated timing network configuration information, and a third format used in response to an update of the time zone offset or the daylight savings time offset.

14. The computer system of claim 11, wherein the method further includes using one or more current parameters upon condition that said determining produces a positive result.

15. The computer system of claim 11, wherein the predetermined time is the maximum freewheel interval for a server in said network, said maximum freewheel interval being based on a maximum skew rate.

16. The computer system of claim 11, wherein the server receiving the information response packet has a same coordinated timing network identifier as a transmitting server of the information response packet.

17. The computer system of claim 11, wherein the information response packet is transmitted, in response to detecting the at least one parameter has changed at another server, wherein the detecting uses a parameter key field of an information response packet to determine the at least one parameter has changed.

18. A method for updating parameters in a coordinated timing network, the method comprising:

receiving by a server of a coordinated timing network identified by a coordinated timing network identifier an information response packet that includes at least one parameter to be changed at the server and specifies a time at which the at least one parameter is to be changed, the at least one parameter being associated with the coordinated timing network, the coordinated timing network comprises a plurality of servers that are time synchronized and receive timing information from stratum-1 server of the coordinated timing network;

responsive to the receiving, determining at the server whether the server is in communication with a clock source;

in response to the determining producing a negative result, waiting for a predetermined time to address a temporary loss of communication with the clock source and then determining whether the server is in communication with the clock source, wherein in response to the determining still providing a negative result, declaring one or more parameters at the server to be invalid and not changing the at least one parameter at the specified time; and

responsive to the determining indicating that the server is in communication with the clock source, changing the at least one parameter at the time at which the at least one parameter is to be changed.

19. The method of claim 18, wherein the server receiving the information response packet has a same coordinated timing network identifier as a transmitting server of the information response packet.

20. The method of claim 18, wherein the information response packet is transmitted, in response to detecting the at least one parameter has changed at another server, wherein the detecting uses a parameter key field of an information response packet to determine the at least one parameter has changed.