Abstract: A method for communication in a packet data network including at least first and second subnets interconnected by routers. The method includes defining at least first and second classes of link-layer traffic within the subnets, such that the link-layer traffic in the first class is transmitted among nodes in the network without loss of packets, while at least some of the packets in the second class are dropped in case of network congestion. The routers are configured by transmitting control traffic over the network in the packets of the second class. Data traffic is transmitted between the nodes in the first and second subnets via the configured routers in the packets of the first class.

Abstract: A system for serving N optical communication lines by a redundant set of modules in an optical network; where the set of modules comprises N>1 main modules and one backup module, N optical splitters, 2N fiber connections and a control means. In the system, each of the N optical splitters is connected to two different modules of the set by two respective fiber connections out of the 2N connections, while each of the N optical splitters is also coupled to one of the N optical communication lines. The arrangement is such that the control means selectively activates/inactivates any of the fiber connections for respectively enabling/blocking transfer of data there-along; the control means thus ensures that each specific line of the N optical communication lines is always served by either one or another of two different modules.

Abstract: A system for serving N optical communication lines by a redundant set of modules in an optical network; where the set of modules comprises N>1 main modules and one backup module, N optical splitters, 2N fiber connections and a control means. In the system, each of the N optical splitters is connected to two different modules of the set by two respective fiber connections out of the 2N connections, while each of the N optical splitters is also coupled to one of the N optical communication lines. The arrangement is such that the control means selectively activates/inactivates any of the fiber connections for respectively enabling/blocking transfer of data there-along; the control means thus ensures that each specific line of the N optical communication lines is always served by either one or another of two different modules.

Abstract: An inverse multiplexing method for transmitting data via multiple data links and a system for implementing same. Efficient utilization of links having disparate data rates is provided by apportioning data units to the links in proportion to their data rates. Rather than perform the apportioning algorithm in real time, the algorithm is executed off-line, and the results recorded as a mapping vector. The mapping vector is used by the transmitter to apportion data units to the links, and by the receiver to re-assemble the data units.

Abstract: An inverse multiplexing method for transmitting data via multiple data links by apportioning the symbols to be transmitted among the available communication links in proportion to the individual communication links' symbol transmission rates in a predictable manner, and a system, including a transmitter and a receiver, employing this method. Preferably, a table shared by the transmitter and receiver is used by the transmitter to apportion the symbols to the various communication links and by the receiver to reconstruct the original data. The method allows fine granularity in the division of symbols, which in turn allows for short messages to be transmitted at high speed, and with minimal latency, by using the full capacity of the communication links, with a minimum of overhead.