International Business Machines Corporation

Judith A Wierbowski

Scott M Carlson

Dennis J Dahlen

Donald Crabtree

Denise M Sevigny

Noshir R Dhondy

Ronald Morton Smith, Sr

Michel H T Hack

David Arlen Elko

David E Whitney

Stephen P Cherniak

Georgette L Kurdt

Thomas B Mathias

Richard Jeffrey Planutis

Michael Ht Hack

Michael H T Hack

A stratum-1 configuration for a timing network is defined. The stratum-1 configuration includes a single active stratum-1 server usable in ensuring that the servers in the network use the same primary reference time to synchronize their clocks. The servers in the network are synchronizing to the same root primary reference time and synchronization accuracy is not dependent on the quality of an external time source or of the existence of an external time source at the stratum-1 server.

Employing configuration information to determine the role of a server in a coordinated timing network

Server time protocol (STP) messages and methods of exchange thereof are provided for facilitating synchronization of processing units of a timing network. The STP messages include exchange time parameters (XTP) commands and responses, and STP control (STC) commands and responses. XTP message exchange processing includes: generating an XTP message command at a first processing unit including a command transmit timestamp field set by the first processing unit and a command receive timestamp field which is unset by the first processing unit; transmitting the XTP message command to a second processing unit; setting the command receive timestamp field in the XTP command with the time the XTP command is received at the second processing unit; and generating an XTP message response at the second processing unit, the message response including the command transmit timestamp set by the first processing unit and the command receive timestamp set by the second processing unit.

Server time protocol messages and methods

Communication and processing within a timing network that supports servers having different capabilities are facilitated. Individual servers of the network are dynamically updated without disrupting the operational characteristics of the timing network. New capabilities are not utilized between two servers until it is known that both servers are capable of supporting the new features. One server communicates to another server at an acceptable level of the another server.

Coordinated timing network having servers of different capabilities

A server of a network of servers determines that its power source is failing. In response, the server communicates to one or more other servers of this network that it is leaving the network. This communication is powered by another power source.

Backup power source used in indicating that server may leave network

A failsafe recovery capability for a Coordinated Timing Network. The recovery capability facilitates recovery when communication is lost between two servers of the coordinated timing network. The capability includes checking another system's status in order to determine what action is to be taken. The status includes the stratum level of the servers and a version number indicating the code level of the servers.

Failsafe recovery facility in a coordinated timing network

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.

Coordinated timing network configuration parameter update procedure

Server time protocol control messages and methods

A primary time server of a Coordinated Timing Network remains as current time server, even if time code information of the primary time server is unavailable. The primary time server receives the necessary or desired timing information from a secondary time server and uses that information to maintain time synchronization within the Coordinated Timing Network.

Maintaining a primary time server as the current time server in response to failure of time code receivers of the primary time server

A timing network is provided that includes a plurality of servers. The servers of the network obtain information used to maintain the servers in time synchronization, thus ensuring the integrity of the servers.

Definition of an active stratum-1 server in a coordinated timing network

Recovery is provided in a timing network. A configuration is defined for that network, and in that configuration, an active primary server is identified that provides a clock source for the network. Additionally, an alternate server is identified that can perform the role of the active primary server, should the active primary server fail. In response to a failure of the primary server, the alternate server detects the failure and performs takeover of the primary server.

Facilitating recovery in a coordinated timing network

Facilitating synchronization of servers in a coordinated timing network

A method and apparatus for automatically associating physical network addresses with logical identifiers in local area networks. The physical network address is transmitted to a central administrator of the local area network, where the association between such address and a logical identifier is made. In the case where a new device is being installed on the network, the logical identifier may be an arbitrary word, number, or combination thereof which is supplied by the operator at the central administrator. In the situation where a device is being replaced, the logical identifier is the same as the identifier of the replaced device, while the physical network address of the replacement device is substituted in the association for the address of the replaced device. A compilation of the associations is maintained at the central administrator, and the associations are transmitted back to the devices being installed or replaced, as well as other devices on the network. A removal procedure is also utilized, whereby a selected association(s) may be removed from the system.

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Owego, NY, United States of America

Judith A Wierbowski