Abstract: A first node provides a time function to a second node. The first node generates a time function protocol data unit required for supporting the time function and generates a plurality of preamble protocol data units. The plurality of preamble protocol data units are sent before the time function protocol data unit. The preamble protocol data units carry routing information to cause the preamble protocol data units to follow a same network path as the time function protocol data unit. At an intermediate node the plurality of preamble protocol data units, the time function protocol data unit and other data traffic are stored in queues of different priority level. The intermediate node controls a time order of forwarding based on priority levels of the queues.

Abstract: A first node provides a time function to a second node. The first node generates a time function protocol data unit required for supporting the time function and generates a plurality of preamble protocol data units. The plurality of preamble protocol data units are sent before the time function protocol data unit. The preamble protocol data units carry routing information to cause the preamble protocol data units to follow a same network path as the time function protocol data unit. At an intermediate node the plurality of preamble protocol data units, the time function protocol data unit and other data traffic are stored in queues of different priority level. The intermediate node controls a time order of forwarding based on priority levels of the queues.

Abstract: A pluggable transceiver module (200) comprising a line receiver (208) connected to a unit interface transmitter (202), a line transmitter (206) connected to a unit interface receiver (204) and a timestamp counter (210) adapted to generate counter values based on clock signals received from an external source and to send the counter values to the line transmitter (206) and to the line receiver (208). The line transmitter (206) and the line receiver (208) are adapted to associate timing packets in a stream of data packets transmitted and received by the pluggable transceiver module (200) with counter values output by the timestamp counter (210).

Abstract: A technique for facilitating clock recovery in a node of a packet-based network is disclosed. The node is synchronized with other nodes based on a master-slave clock mechanism. A list of backup master clock node is maintained for the node, which includes at least one backup master clock node for the node, and in response to occurrence of a synchronization related event, a master clock node of the node is switched from the current master clock node to a backup master clock node selected from the list. A master clock node reselection message is generated and transmitted to the switched backup master clock node for the switched backup master clock node to reselect its master clock node.

Abstract: A technique for facilitating clock recovery in a node of a packet-based network is disclosed. The node is synchronized with other nodes based on a master-slave clock mechanism. A list of backup master clock node is maintained for the node, which includes at least one backup master clock node for the node, and in response to occurrence of a synchronization related event, a master clock node of the node is switched from the current master clock node to a backup master clock node selected from the list. A master clock node reselection message is generated and transmitted to the switched backup master clock node for the switched backup master clock node to reselect its master clock node.

Abstract: A pluggable transceiver module (200) comprising a line receiver (208) connected to a unit interface transmitter (202), a line transmitter (206) connected to a unit interface receiver (204) and a timestamp counter (210) adapted to generate counter values based on clock signals received from an external source and to send the counter values to the line transmitter (206) and to the line receiver (208). The line transmitter (206) and the line receiver (208) are adapted to associate timing packets in a stream of data packets transmitted and received by the pluggable transceiver module (200) with counter values output by the timestamp counter (210).

Abstract: A protection system for an ATM network (30) having a primary node (11,21) and a secondary node (12,13,14, 22) interconnected through an ATM transport capable network (30) of any topology. For each ATM (VPC/VCC) connection between the primary (11,21) and the secondary node (12, 13,14,22) this interconnecting network (30) makes available two independent paths (16, 17) that form independent working and protection paths. The primary node (11,21) sends traffic cells over both working path (16 or 17) and protection path (17 or 16) and receives and merges the traffic cells from both the paths (16 and 17). The secondary node (12, 22) transmits and receives traffic cells either on the bi-directional working path (16 or 17) or on the bi-directional protection paths (17 or 16) and the continuity of the working and protection path is monitored through the creation of appropriate ATM test circuits, named Test Trails (19, 20), between the primary node (11,21) and the secondary node (12,13,14,22).