Abstract: Embodiments of a method implemented in at least one fat tree network node for improved load distribution, wherein the node is one of a plurality of fat tree network nodes in a fat tree network each of which implement a tie-breaking process to produce minimum cost trees, is described. In some embodiments, a spanning tree computation for each root node of the fat tree network in order from a lowest ranked root node to a highest ranked node is performed, a filtering database for each root node of the fat tree network, wherein the filtering database includes a set of media access control (MAC) addresses of the leaf nodes of the fat tree network generated, and link utilization for each computed tree to use as a prefix to link identifiers used for at least one tie-breaking algorithm added.

Abstract: Nodes on a link state protocol controlled Ethernet network implement a link state routing protocol such as IS-IS. Nodes assign an IP address or I-SID value per VRF and then advertise the IP addresses or I-SID values in IS-IS LSAs. When a packet is to be forwarded on the VPN, the ingress node identifies the VRF for the packet and performs an IP lookup in customer address space in the VRF to determine the next hop and the IP address or I-SID value of the VRF on the egress node. The ingress node prepends an I-SID or IP header to identify the VRFs and then creates a MAC header to allow the packet to be forwarded to the egress node on the link state protocol controlled Ethernet network. When the packet is received at the egress node, the MAC header is stripped from the packet and the appended I-SID or IP header is used to identify the egress VRF.

Abstract: Embodiments of a method implemented in at least one fat tree network node for improved load distribution, wherein the node is one of a plurality of fat tree network nodes in a fat tree network each of which implement a tie-breaking process to produce minimum cost trees, is described. In some embodiments, a spanning tree computation for each root node of the fat tree network in order from a lowest ranked root node to a highest ranked node is performed, a filtering database for each root node of the fat tree network, wherein the filtering database includes a set of media access control (MAC) addresses of the leaf nodes of the fat tree network generated, and link utilization for each computed tree to use as a prefix to link identifiers used for at least one tie-breaking algorithm added.

Abstract: A resilient virtual Ethernet ring has nodes interconnected by working and protection paths. If a span fails, the two nodes immediately on either side of the failure are cross-connected to fold the ring. Working-path traffic is cross-connected onto the protection path at the first of the two nodes and is then cross-connected back onto the working path at the second of the two nodes so that traffic always ingresses and egresses the ring from the working path. A traffic originating node, upon determining that transmitted packets are being looped back due to a fault on a primary path, is adapted to switch transmission of data packets from the primary path to a secondary path.

Abstract: In a hybrid fiber-coax distribution network, communications between a central station and particular end stations are encrypted using a working key (WK) of a symmetric encryption scheme. The central station has a public and private key (PPK) of a PPK encryption scheme, and some of the end stations can also each have a respective PPK. To provide secure communications for each end station, if the end station has a PPK, then the respective WK is generated in the central station and communicated, encrypted using the end station's public key (PK), to the end station. Otherwise, the WK is generated in the end station and communicated, encrypted using the central station's PK, to the central station. An individual identifier for each end station, and a cryptographic signature at least for end stations not having a PPK, can be communicated to the central station for authentication of the end stations.

Abstract: A distribution network groups television program signals into service tiers. To provide these from unsynchronized MPEG streams without resynchronization, each stream, representing a single program signal is encapsulated into ATM cells with a virtual path (VP) identification of each ATM cell corresponding to the service tier and a virtual channel (VC) identification corresponding to the respective program signal. Payloads in cells having the same VP are scrambled using a scrambling key allocated to that VP and hence to the corresponding service tier, and are unscrambled by entitled subscribers using the scrambling key which is supplied to them individually using public/private encryption techniques.