Abstract: In order to upgrade firmware at network elements in a communications network a network upgrade protocol agent is installed on each network element. These agents run an upgrade protocol which allows an upgrade to be loaded onto a first network element and then broadcast through the network. The protocol includes notification messages, which change the state of the network elements to which the upgrade relates, download messages which include the firmware upgrade, apply messages which instruct relevant network elements to apply the upgrade, and inventory messages which send an inventory of firmware stored at a network element to neighboring elements to enable a determination to be made of whether a network element has received all relevant firmware upgrades.

Abstract: In order to upgrade firmware at network elements in a communications network a network upgrade protocol agent is installed on each network element. These agents run an upgrade protocol which allows an upgrade to be loaded onto a first network element and then broadcast through the network. The protocol includes notification messages, which change the state of the network elements to which the upgrade relates, download messages which include the firmware upgrade, apply messages which instruct relevant network elements to apply the upgrade, and inventory messages which send an inventory of firmware stored at a network element to neighboring elements to enable a determination to be made of whether a network element has received all relevant firmware upgrades.

Abstract: To perform non-blocking cross connections in a high data rate switch operative for switching a synchronous data stream where the data is arranged in groups, the bits of the data groups are spread into subsets of one or more bits and the subsets switched individually across lower bit rate switches. At the destination the subsets are recombined. The bit spreader and recombiner may be arranged on the switch card or at the source and destination interfaces respectively. A protection switch can provide 1:N protection and an XOR function can be incorporated with the protection switch to provide 1:N protection without signalling from the destination interface to the source interface.