Abstract: Routing tables of OSI layer-3 network elements are modified in order to enable entry to a RPR subnet at different entry points. This enables virtual tunnels or routing paths to utilize all existing entry links to the RPR subnet and to minimize cost factors, such as the number of RPR spans required to traverse the RPR subnet from the entry point to a destination RPR node. The routing tables of RPR subnet elements are modified, such that traffic leaving different elements but destined for the same network location outside the RPR subnet may have individualized RPR exit nodes. The respective RPR exit points for the network elements are chosen to minimize cost factors, such as the number of RPR spans required to reach the exit node from each RPR node.

Abstract: A point-to-point protocol (PPP) proxy module enables subscribers to seamlessly establish multiple, simultaneous PPP connections with one or more telecommunications networks through different service providers offering various services. The PPP connections are established over an access network maintained by an access provider. The subscriber performs a service selection process over a PPP connection that serves as dedicated control link between the subscriber's customer premises equipment (CPE) and the PPP proxy module. When a subscriber performs the service selection process, the PPP proxy module references stored information about the selected telecommunications network, and establishes a PPP connection that serves as a transmission link for media or other content between the CPE and a telecommunications network having the selected service.

Abstract: A method of ring protection is provided. The method includes feeding traffic on two transmission rings at a head end node and summing all traffic received on the transmission rings at the head end node. When a facility failure is detected, by a remote node, on one of the two transmission rings, transmitting forward alarm signals on the one transmission ring and return alarm signals on the other transmission ring and globally selecting the one transmission ring to transmit traffic and the other transmission ring to receive traffic from the head end node. When a remote node receives a forward alarm signal, the remote node passes the forward alarm signal on the transmission ring on which the forward alarm signal was received and globally selects the transmission ring on which the forward alarm signal was received to transmit traffic and the other transmission ring to receive traffic from the head end node.

Abstract: An electronic digital signal cross-connect system (EDSX) is provided which includes a plurality of input terminals for respectively receiving bipolar 3-level input signals having a predetermined bit rate, and a plurality of output terminals for respectively providing bipolar 3-level output signals having the same predetermined bit rate. An interface circuit is provided which has an input section coupled to the input terminals to receive the bipolar 3-level input signals and an output section coupled to the output terminals to output the bipolar 3-level output signals. The input section of the interface circuit is constructed to include converting circuitry for converting the bipolar 3-level input signals into predetermined coded signals. Correspondingly, the output section of the interface circuit includes converting circuitry for decoding the predetermined coded signals into bipolar 3-level output signals.