International Business Machines Corporation

Chin Lee

Bruce H Ratcliff

Stephen R Valley

Paul M Gioquindo

Thomas Anthony Gregg

Joseph M Hoke

Albert Ing

In a mainframe class data processing system having multiple logical partitions and a port to a network, a host-network interface is established for reducing network overhead at the multiple partitions. The host-network interface includes, for example, a host channel connection coupling the multiple partitions of the host system to a communications adapter having a network device driver for each network coupled to the adapter. The adapter also includes an address resolution protocol (ARP) cache designed to hold predetermined media headers for the clients coupled to the network(s) for use in forwarding an internet protocol (IP) datagram across the network to one of the clients from a partition of the host system. Provision is also made for partition-to-partition communication of IP datagrams by storing IP addresses of the logical partitions as HOME addresses in the ARP cache of the adapter.

Communication between multiple partitions employing host-network interface

A method of multicasting messages in a computing network environment having at least one host and a plurality of clients connected and in processing communication with one another via a gateway device. Host(s) and client(s) requesting registration will be registered and their information will be entered in a routing table, one entry dedicated to each host or client. A connectivity platform controls all communication between the host and the client(s) by receiving all information packets. The Routing table is then searched and the packets are distributed accordingly to their owner once a matching entry is found. If a matching entry is not found the packet will be dropped.

IP multicast interface

A multicasting apparatus that broadcasts messages to at least some of the clients in a computing network environment having a plurality of clients and at least one host connected to these clients via a gateway device. A multicast routing table is created for registering any host and clients requesting registration. The table will include one entry per host/client and includes their relevant information. A connectivity platform is used for controlling all communications so that all information packets is first received by the platform. Upon the receipt of a packet, the table is searched and if an match is found the packet will be routed using the entry information; otherwise, the packet will be dropped.

A computer program product for use with a computer system having a host and a plurality of clients coupled to one another via a local area network (LAN), to provide a multicasting of messages using a special command set. First computer readable code means is generated for issuing a first special command to add a new IP multicast address providing a group multicast address and an IP multicast address. Then computer readable code means is created for entering said special control command in a multicast routing table, one entry per connection request received. Computer readable code means is then provided for a use count mechanism for keeping track of numbers of communication stacks which have registered with a certain IP multicast address. Also computer readable code means is generated for comparing all inbound IP packets destined for an IP multicast address with said entries in said table and routing all matches to their appropriate communication stacks.

In a mainframe class data processing system having multiple logical partitions and a port to a network, a host-network interface is established for reducing network overhead at the multiple partitions. The host-network interface includes, for example, a host channel connection coupling the multiple partitions of the host system to a communications adapter having a network device driver for each network coupled to the adapter. The adapter also includes an address resolution protocol (ARP) cache designed to hold predetermined media headers for the clients coupled to the network(s) for use in forwarding an internet protocol (IP) datagram across the network to one of the clients from a partition of the host system. If not predetermined, the adapter is provided with a capability to dynamically determine the needed media header for transmission of the IP datagram across the network to the client. In Ethernet format, this dynamically determining includes forwarding an Ethernet 802.3 ARP request and an Ethernet DIX ARP request from the IP datagram. Provision is also made for partition-to-partition communication of IP datagrams by storing IP addresses of the logical partitions as HOME addresses in the ARP cache of the adapter.

Article of manufacture for communications of multiple partitions employing host-network interface, and address resolution protocol for constructing data frame format according to client format

Method of using address resolution protocol for constructing data frame formats for multiple partitions host network interface communications

System for communications of multiple partitions employing host-network interface, and address resolution protocol for constructing data frame format according to client format

A method in a computing network environment for host partition computers to share a multicast communication adapter connected to a local area network. Each host partition sends information identifying the host application as well as a multicast addressing protocol to the shared multicast communication adapter. The communication adapter registers the information and directs inbound multicast packets from the LAN to the appropriate host partition application. In a preferred embodiment, the communication adapter registers the information according to the IP multicast address. In a preferred embodiment, a counter is employed in the communication adapter to maintain a count of the number of host applications that are registered. The invention further provides a method for un-registering a host partition application.

Method for shared multicast interface in a multi-partition environment

A system and method for asynchronously transmitting data across fibers in a serial manner. Frames are provided as a mechanism to transmit associated data serially and tie the data being transmitted to a particular buffer set. Each buffer set maintains a state that keeps track of the progress and sequence of received frames. When transmission errors occur in the frames, the errors may affect header bits in the frame that identify the buffer set and the frame type. In this case, the entire frame is lost and the operation usually results in a timeout of the operation. By using this state information some of these lost frames can be recovered avoiding the lengthier timeout recovery procedure.

Recovery of lost frames in a communication link

A system and method for asynchronously transmitting data across fibers in a serial manner. Frames are provided as a mechanism to transmit associated data serially and tie the data being transmitted to a particular buffer set. Each outstanding request for each buffer set is individually timed to detect lost frames, and each buffer set maintains a state that keeps track of the progress and sequence of received frames. When transmission errors occur in the frames, the errors may affect only the information field and there is enough information in the header to identify the frame. A request can then be sent back to the other end of the fibers to retransmit the frame. In some instances, the frame cannot be retransmitted because the content of the data may have been changed by other operations in the systems. To speed recovery in these situations, the requester of the retransmitted frame sets a much shorter timer while waiting for the response since the retransmitted frame will be sent quickly, if at all.

Shortened timeout period during frame retry in a communication link

A system and method for asynchronously transmitting data across fibers in a serial manner. Frames are provided as a mechanism to transmit associated data serially and tie the data being transmitted to a particular buffer set. Each buffer set maintains a state that keeps track of the progress and sequence of received frames. When transmission errors occur in the frames, the errors may affect only the information field and there is enough information in the header to identify the frame. A request can then be sent back to the other end of the fibers to retransmit the frame. Certain information in the frame header is not used to identify the frame, but is used to control the transfer of frames and identify lost frames. When a frame information field is damaged by transmission errors, this header information is retained by the receiver of the damaged frame. Retaining this information at the receiver of the damaged frame frees the sender for storing it during the transmission of each frame. Freeing the sender improves performance by removing steps for the normal error free transmission of frames.

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Poughkeepsie, NY, United States of America

Chin Lee