Abstract: A method, network receiver and TCP network that enables a receiver-side triggering of the fast retransmit mechanism when a TCP packet/segment is lost or received out-of sequencing order. The receiver is enhanced with a Fast Retransmit Support (FRS) utility that monitors when a next received packet is out-of-order and responds by transmitting a duplicate acknowledgment (ACK) response that includes therein the same window value as the previous ACK. By including the previous clock time, even when the current window value has advanced, the fast retransmit algorithm at the transmitter is triggering before the timeout period.

Abstract: A method, system, and program provide for efficient send socket call handling by a transport layer. A transport layer of a network protocol stack receives a send socket call for data of a specified length from an application layer. Responsive to detecting that there is insufficient memory for a single memory allocation to a buffer in the transport layer for at least the specified length, the transport layer blocks the send socket call. The transport layer only wakes the send socket call upon detection of sufficient memory for the single memory allocation within the buffer of the transport layer for at least the specified length, wherein waking the send socket call triggers a kernel to perform the single memory allocation in the buffer and to write the data to the single memory allocation in a single pass.

Abstract: A mechanism is provided for identifying a snooping device in a network environment. A snoop echo response extractor generates an echo request packet with a bogus MAC address that will only be received by a snooping device. The snoop echo response extractor also uses an IP address that will cause the snooping device to respond to the echo request.

Abstract: A method in a data processing system for reducing the learning curve of a transmission control protocol connection. A domain name system is queried for information. The information and a previously used transmission control protocol parameter for a transmission control protocol connection are received from the domain name system. The information and the previously used transmission control protocol parameter are used to configure a current transmission control protocol connection.

Abstract: An improved method in a data processing system for forwarding network file system requests and responses between network segments. A notice is received that data has arrived at a receive buffer for a socket. The receive buffer is connected for the socket and a send buffer for another socket to form a splice. Both the socket and the other socket are flagged as a spliced connection.

Abstract: A system and method of responding to a full TCP queue. After a server receives a TCP connection request from a client, the server places the request on an embryonic queue of TCP connection requests sorted by the amount of elapsed time since the server has respond to each respective TCP connection request. When the server attempts to place a new TCP connection request on a full embryonic queue, the host, via the TCP protocol, will remove the entry at the end of the embryonic queue. The last entry, due to the high timer value, is more likely to having performed unsuccessful attempts at completing a connection.

Abstract: A system and method of responding to a flood attack on a data processing system is disclosed. The present invention mitigates the affects of SYN attacks with false IP addresses by immediately removing the associated embryonic connection from the system upon receiving notification that the IP address in the original SYN request is false. Immediate removal of the connection request will mitigate the effects of the flood attack by not requiring the system to devote resources to servicing a connection request from a false IP address, which could result in denial of service for legitimate clients. Immediate removal of the connection request will mitigate the effects of the flood attack by not requiring the system to devote resources to servicing a connection request from a false IP address, which could result in denial of service for legitimate clients.

Abstract: A method, apparatus, and computer instructions code for sending data to a destination. A set of address resolution protocol entries is searched for an entry matching an Internet Protocol address for the destination and a particular interface in response to selecting the particular interface from a set of interfaces in the data processing system to send the data to the destination. The destination has a plurality of interfaces using the Internet Protocol address with each interface in the plurality of interfaces having a different media access control address. In response to a presence of the entry in the set of address resolution protocol entries, a media access control address in the entry is used to send the data to the destination.

Abstract: A method, apparatus, and computer instructions for transferring data in a network data processing system. Data is transferred to a destination in which an address resolution protocol entry is used to transfer this data to the destination. A determination is made as to whether the address resolution protocol entry will expire within a selected threshold while transferring data to the destination. If the address resolution protocol will expire within the selected threshold, the address resolution protocol entry is kept or retained to reduce the interruptions or delays in the transferring of the data.

Abstract: Methods, system, and products are disclosed for administering requests for data communications connections in a wide area network that include receiving, according to a data communications protocol, by a receiver from a sender, a request for a data communications connection, wherein the sender has a network address on a sender's network and the receiver has a network address on a receiver's network; characterizing the sender as local with respect to the receiver's network if the sender's network is the receiver's network; characterizing the sender as remote with respect to the receiver's network if the sender's network is not the receiver's network; and responding to the request in dependence upon a value of a location response flag and in dependence upon the characterization of the sender's network with respect to the receiver's network.

Abstract: Administering acknowledgment messages (‘ACKs’) in the Transmission Control Protocol (“TCP”) that include establishing a TCP connection between a sender and a receiver, receiving by the receiver one or more TCP messages from the sender, and transmitting an ACK from the receiver to the sender only when necessary. Administering ACKs in TCP according to embodiments of the present invention may include measuring by the sender a round trip time for transmission of TCP messages between the sender and the receiver and transmitting to the receiver a data-bearing TCP message once per round trip time. Establishing a TCP connection between a sender and a receiver may include measuring by the receiver a round trip time for transmission of TCP messages between the receiver and the sender. Transmitting an ACK only when necessary may include transmitting an ACK when no message from the sender arrives at the receiver for two round trip times.

Abstract: A method, apparatus, and computer instructions for reactivating an existing connection to a remote data processing system. A data packet is created using a previously acknowledged sequence number for the connection. The sequence number is used to uniquely number data bytes sent in a connection, such as a TCP connection. With this sequence number, devices and components, such as routers and fire walls will forward the packet to the destination. A special data sequence, such as a MAC address of the remote data processing system repeated a selected number of times, is placed in the data packet. This special data sequence causes the remote data processing system to wake up from a sleep mode when received by the remote data processing system. The data packet is sent to the remote data processing system using the existing connection. The use of a subnet directed broadcast is avoided. Thus, problems associated with routing wake up packets are avoided.

Abstract: A method, system and apparatus for reducing dataflow disruption when increases in path maximum transmission unit (PMTU) are being detected are provided. Conventionally, when increases in PMTU are being detected, an increased-in-size data packet is sent by a transmitting host. If an intermediate link is unable to process the data packet through, it drops the data packet and sends an error message to the transmitting host. The transmitting host has to reduce the size of the data packet and resend it. The procedure outlines in this disclosure obviates the need to resend the data packet. It does so by transmitting an old data packet that has been increased in size. Hence, there is no need to resend the data packet if it is dropped.

Abstract: The present invention provides a method, system, and computer program product for splicing proxied web requests with callback for subsequent requests. The method comprises: initiating by a proxy a Transmission Control Protocol (TCP) splice between first and second socket connections in order to service a request; and returning control of the first and second socket connections to the proxy in response to a completion event associated with the TCP splice.

Abstract: Determining availability of a destination for computer network communications that include providing on a caching device a destination availability cache comprising at least one cache entry representing availability of a destination and providing, from the caching device to a source, through computer network communications, information indicating the availability of the destination. In typical embodiments, the cache entry comprises a network address of a destination device and a time limitation for the cache entry.

Abstract: An apparatus and method for an improved bulk read socket call are provided. With the apparatus and method, a new field, so_rcvlen, is added to the socket structure that identifies the bulk read size requested by the user. The kernel of the prior art recv( ) function is also modified so that it sets the so_rcvlen to the size requested by the user prior to the recv( ) function going to sleep and waiting for the full data size requested by the user. A new flag, SP_MSGWAITALL, is also provided in the socket structure. In the TCP input processing, when data is received for a particular socket, the current setting of the SP_MSGWAITALL is checked. If the SP_MSGWAITALL flag is set, it is determined whether the amount of data stored in the socket receive buffer is less than the value of so_rcvlen. If not, the TCP input processing does not wake up the recv( ) thread. However, for every alternate segment, the TCP input processing sends back an acknowledgment (ACK).

Abstract: A TCP/IP retransmission frame contains multiple TCP segments containing non-contiguous missing packets from a data communication. A TCP option in the first segment in the frame indicates the presence of multiple TCP payloads in the frame. Each TCP payload has a corresponding prepended TCP header. An offset address specified in each TCP header within the frame identifies the location of the next TCP header in the frame. Network throughput performance is enhanced by permitting multiple non-contiguous packets to be retransmitted in a single IP packet.

Abstract: The reassembly timer in a TCP/IP receiver is dynamically set to avoid data corruption on fast networks caused by IP identification wrap-around. A sender generates IP packets with a special option specifying a reassembly time for fragments based on the subnet of the destination or on the calculated round-trip time of the connection. A receiver sets the reassembly timer to the reassembly time specified in the option. A sender can generate IP packets with an alternative option setting a time stamp for the generated packet. A receiver calculates a traversal time based on the difference between the arrival time of the fragment and this time stamp, and sets the reassembly timer based on this traversal time.

Abstract: The reassembly timer in a TCP/IP receiver is dynamically set to avoid data corruption on fast networks caused by IP identification wrap-around. A receiver independently sets the reassembly timer to a first reassembly time set by the user for fast networks or to a second reassembly timer set by the user for slow networks based on whether the receiver and sender are on the same subnet.

Abstract: An apparatus and method for an improved bulk read socket call are provided. With the apparatus and method, a new field, so_rcvlen, is added to the socket structure that identifies the bulk read size requested by the user. The kernel of the prior art recv( ) function is also modified so that it sets the so_rcvlen to the size requested by the user prior to the recv( ) function going to sleep and waiting for the full data size requested by the user. A new flag, SP_MSGWAITALL, is also provided in the socket structure. In the TCP input processing, when data is received for a particular socket, the current setting of the SP_MSGWAITALL is checked. If the SP_MSGWAITALL flag is set, it is determined whether the amount of data stored in the socket receive buffer is less than the value of so_rcvlen. If not, the TCP input processing does not wake up the recv( ) thread. However, for every alternate segment, the TCP input processing sends back an acknowledgment (ACK).