Techniques employed in packet networks for transferring a packet across subnetworks with different namespaces. When a packet enters a given subnetwork and has a destination in a subnetwork with a different namespace, the given subnetwork encapsulates the packet by adding a header which specifies a decapsulator in the namespace. When the packet arrives at the decapsulator, the decapsulator strips the header and provides the packet to a subnetwork with a different namespace. A particular use of the technique is in a network used for broad-band interactive service. The network has two sub-networks. The first subnetwork is a TV channel which functions as a high-bandwidth forward channel and the second subnetwork is a packet network accessible via a public modem pool which functions as a lower-bandwidth return channel. The encapsulator establishes a connection with the public modem pool and receives an address in the second subnetwork which is temporarily associated with the connection. When the encapsulator receives a packet which is produced in response to a packet received from the TV channel and has a destination address in the sub-network of the TV channel, the encapsulator places a header on it which contains the temporary address and the address of the decapsulator. When the packet arrives at the decapsulator, the decapsulator removes the header and provides the packet to the second sub-network.
An apparatus and method for encapsulating and forwarding packets on a network are disclosed. The network can include a first subnetwork such as a virtual private network connected to a larger public network such as the Internet. An encapsulating header is attached to a packet to be transferred across the public network from a source node on the private network to a destination node on the private network, such that the packet can be transferred across the public network. The encapsulating header includes a value which is derived from the private header on the packet used to transfer the packet along the private network. The value is therefore associated with a source/destination pair within the private network. The value can be derived by performing a hash operation on the private network header. After the public network header containing the value derived from the private network header is attached to the packet, it can be forwarded across the public network. A logical operation such as a hash operation can be performed on the public network header to select one of a plurality of possible paths on the public network to forward the packet. As a result, each source/destination pair within the private network will be associated with a path within the public network. Traffic from the private network can therefore be distributed over multiple paths in the public network, thus reducing or eliminating traffic congestion and overload.
A computer system may include one or more hosts and a plurality of data storage devices for providing multihop system calls. The data storage devices are interconnected and also connected to the one or more hosts. The connections may be direct or indirect. Each data storage device classifies a data operation as a system call, a remote system call, or a multihop system call. If an operation is classified as a multihop system call by a first data storage device, a portion of the data associated with the multihop system call is removed and a second portion of the data is forwarded to a second data storage device as specified by a connection identifier included in the first portion. A recursive process of removing a first portion and forwarding a second portion of data associated with the multihop system call is performed by each data storage device forwarded a second portion of data until a data storage device receives a second portion that is interpreted as a system call or a remote system call.
An apparatus and method for encapsulating and forwarding packets on a network are disclosed. The network can include a first subnetwork such as a virtual private network connected to a larger public network such as the Internet. An encapsulating header is attached to a packet to be transferred across the public network from a source node on the private network to a destination node on the private network, such that the packet can be transferred across the public network. The encapsulating header includes a value which is derived from the private header on the packet used to transfer the packet along the private network. The value is therefore associated with a source/destination pair within the private network. The value can be derived by performing a hash operation on the private network header. After the public network header containing the value derived from the private network header is attached to the packet, it can be forwarded across the public network. A logical operation such as a hash operation can be performed on the public network header to select one of a plurality of possible paths on the public network to forward the packet. As a result, each source/destination pair within the private network will be associated with a path within the public network. Traffic from the private network can therefore be distributed over multiple paths in the public network, thus reducing or eliminating traffic congestion and overload.
An IP data transport method and system that makes efficient use of the subscriber television system bandwidth and uses the existing structure and equipment of the subscriber television system. The method allows several levels of IP data service within a subscriber television system. A subnet connection is established between an IP server in a headend and an external network. The existing communications paths within a subscriber television system are used to establish an IP communications route between the headend and a Home Communications Terminal (HCT). The data is communicated in an Motion Picture Experts Group (MPEG) format. Encapsulating the IP data into an MPEG format allows the existing systems to transport the IP data in the same packet streams it uses for video, audio, and control data.
