437 results about "Ip layer" patented technology

The present invention relates to a switch for processing data units, such as IP data packets. The switch can be implemented as a router that includes a plurality of input ports, a plurality of output ports and a switch fabric capable of establishing logical pathways to interconnect a certain input port with a certain output port. A characterizing element of the router is its ability to control bandwidth usage on a basis of a logical pathway. This prevents congestion to occur in the switch fabric and also at the level of the output ports. For every active logical pathway the router sets-up a bandwidth control mechanism including at least one queue to hold data units received at an input port. The bandwidth control mechanism performs an accounting operation to determine the average bandwidth usage and if less than a threshold requests for releasing data units in the switch fabric are sent to the switch fabric controller. When the threshold is exceeded the bandwidth control mechanism stops sending requests for service to the switch fabric controller. The system also supports priorities. Instead of stopping the issuance of signals requesting release of data packets the priority level of the queue (reflected in a priority field in the signal requesting release of a data packet) changes from HI to LO. The switch fabric controller is designed to recognize priority requests and will accept LO priority requests only when there are no other HI priority requests pending. The present invention also provides a data transport device which includes a plurality of nodes interconnected by a physical link that establishes two ring-shaped paths on which data is transported on opposite directions. Each node is capable of sending a control message to the upstream node to advise the upstream node of the data carrying requirements of the node at which the message has originated. The upstream node can then throttle the introduction of data in the paths to preserve capacity that can be used by the downstream nodes.

The SCSI and iSCSI layers over the TCP / IP layers of the protocol stack in an IP network client and in an IP network-attached storage server are replaced with a thin network block services layer. The network block services layer 71 implements a network block services protocol having a very reduced set of commands transmitted between the client and the storage server. The network block services protocol is used in a configuration process in which logical volumes of the network-attached storage are exported to the client and become local pseudo-disk instances. The client's operating system and application programs access the local pseudo-disk instances with what appears to be a standard device driver for a local disk device. The device driver maintains a TCP connection to each open device, and responds to connection failure by re-connecting with an alternative server IP port.

Methods of transparent connection failover allowing a remote computer (i.e., a client), to continue to use a network connection to communicate with one of at least two or more other computers (i.e., the backup servers) over a network, when one of the other computers (i.e., the primary server) fails. With the mechanisms of this invention, there is no need for the client to establish a new connection to a backup server when the primary server fails. The failover is preferably executed within a bridge layer between the TCP layer and the IP layer of the server's TCP / IP stack. No modifications are required to the network infrastructure, the client's TCP / IP stack, the client application or the server application. The methods support active or semi-active replication of the server application, and do not require rollback of the application during failover. The invention also provides mechanisms for bringing up new backup servers.

The solution of the present invention provides systems and methods for encoding information into an Internet Protocol identification field (IPID) of an IP layer header of a network packet in a manner acceptable to many or all of the network devices that encounter the encoded packet. In one embodiment, the solution described herein encodes the IP identification field of the IPID header with information to be communicated between devices. Appliances may use the encoded IP field as a signal or a means for a low-bandwidth subcarrier of data between the appliances that is transparent to any intervening network equipment. For example, the encoded field may be used to announce or probe the presence of a device, a functionality or capability of device or to indicate a type or speed of a network connection of a port on a device.

A method and system for combining the bandwidth available to a user communications device from multiple access points by switching output requests and corresponding replies to such requests among a plurality of such access points. In the simplest implementation the switching can be on a round-robin basis, but the switching can be enhanced to prioritize and use quality of service requirements associated with each output request, and also to measure congestion at each access point and base switching upon the congestion level. The invention operates by generating subset ISO communication stacks for each available access point, preferably the subset from the IP layer to the data control link, and switching between these stacks.