摘要:
Method and apparatus for extending lower-layer flow control end-to-end, transparent to network host systems, between network hosts attached to legacy networks without requiring any changes to the host networks or hosts themselves. In a first embodiment, a source host and a destination host, each residing on a respective LAN, communicate via an intermediate network supporting the lower-layer flow control. A higher-layer, end-to-end flow control protocol exists between the hosts. The lower-layer flow control protocol accounts for loss of bandwidth between each hop within the intermediate network. To extend the lower-layer flow control protocol to the hosts, an intelligent edge device of the intermediate network adjusts observed higher-layer flow control parameters based upon the state of the lower-layer flow control. No modifications to the legacy network or hosts is required, and the extension of flow control is transparent to the legacy networks.
摘要:
A method is disclosed for facilitating multicast operation in a network in which a data unit is multicast from a root node to a plurality of leaves via a plurality of branching point nodes in response to feedback processed at each branching point node. At least one cell forwarding technique is selected from a plurality of cell forwarding techniques at the respective branching point nodes. The cell forwarding techniques facilitate multicast operation by controlling forwarding and discard of multicast cells. The forwarding techniques are realized via use of a buffer ring in which cells are stored prior to forwarding. Manipulating head and tail pointers associated with the buffer ring allows for a plurality of desirable forwarding techniques.
摘要:
A flow control technique for wide area ATM networks is disclosed in which allocation of buffers in a receiver switch is controlled by a transmitter switch. The receiver switch periodically transmits feedback messages to the transmitter switch indicatative of the state of fullness of the receiver switch buffers. The transmitter switch calculates updated receiver buffer fullness based upon the feedback message and the number of cells transmitted from the transmitter switch to the receiver switch since the feedback message was sent. Transmission of cells from the transmitter switch to the receiver switch is then controlled in accordance with an allocation technique, thereby allocating buffers in the receiving switch. The technique may be a roll-off technique in which the number of buffers available to each flow in the transmitter switch is reduced geometrically as the updated receiver buffer state is calculated to be more full. The flow control technique may be applied on either a per link or a per flow basis.
摘要:
Permission based flow control is implemented in a computer network having at least a downstream, intermediate and upstream network device by receiving credits at the intermediate network device from the downstream network device and granting credits from the intermediate network device to the upstream network device based at least in part upon the credits received at the intermediate network device from the downstream network device. Credit chaining as described above is employed to permit the granting of the right to transmit downstream to be predicated upon buffer availability downstream of the next downstream network device. Via the use of credit chaining, high utilization of network resources is achieved with minimal loss of data traffic.
摘要:
The invention is directed to techniques for receiving the resource request in which the resource request contains a set of resource preference properties and in which the set of resource preference properties has a resource preference property. The data communications device compares the set of resource preference properties to a database of resource definitions to select a resource, the resource being most closely identified with the set of resource preference properties. The result is to provide a resource response from the selected resource.
摘要:
A content-aware flow switch intercepts a client content request in an IP network, and transparently directs the content request to a best-fit server. The best-fit server is chosen based on the type of content requested, the quality of service requirements implied by the content request, the degree of load on available servers, network congestion information, and the proximity of the client to available servers. The flow switch detects client-server flows based on the arrival of TCP SYNs and/or HTTP GETs from the client. The flow switch implicitly deduces the quality of service requirements of a flow based on the content of the flow. The flow switch also provides the functionality of multiple physical web servers on a single web server in a way that is transparent to the client, through the use of virtual web hosts and flow pipes.
摘要:
A content-aware flow switch intercepts a client content request in an IP network, and transparently directs the content request to a best-fit server. The best-fit server is chosen based on the type of content requested, the quality of service requirements implied by the content request, the degree of load on available servers, network congestion information, and the proximity of the client to available servers. The flow switch detects client-server flows based on the arrival of TCP SYNs and/or HTTP GETs from the client. The flow switch implicitly deduces the quality of service requirements of a flow based on the content of the flow. The flow switch also provides the functionality of multiple physical web servers on a single web server in a way that is transparent to the client, through the use of virtual web hosts and flow pipes.
摘要:
A content-aware flow switch intercepts a client content request in an IP network, and transparently directs the content request to a best-fit server. The best-fit server is chosen based on the type of content requested, the quality of service requirements implied by the content request, the degree of load on available servers, network congestion information, and the proximity of the client to available servers. The flow switch detects client-server flows based on the arrival of TCP SYNs and/or HTTP GETs from the client. The flow switch implicitly deduces the quality of service requirements of a flow based on the content of the flow. The flow switch also provides the functionality of multiple physical web servers on a single web server in a way that is transparent to the client, through the use of virtual web hosts and flow pipes.