58 results about "Maximum segment size" patented technology

Disclosed are methods and apparatus for avoiding problems caused by converting between two different protocols, such as IPv4 and IPv6. These problems may include, but are not limited to, fragmentation of packets, dropping of packets, and retransmission of packets. Avoiding these problems will reduce the incidence of transmission delays, bandwidth degradation, and additional processing in the packet's transmission path due to such problems. In general terms, the present invention provides mechanisms for modifying a protocol parameter, such as a TCP or UDP parameter, to avoid problems associated with protocol translation, such as fragmentation. In one implementation, the protocol parameter limits the size of a particular portion of the a packet transmitted by a sending computer node or device. For example, a packet size indicator is communicated to the sending computer node so that the sending computer node sends packets limited by the packet size indicator to thereby avoid associated with the size of such packets. In specific TCP embodiments, the size indicator specifies a window size and/or a maximum segment size. For example, if packets transmitted by a sending node to a receiving node are converted from IPv4 to IPv6 and the window size indicated to the sending node (e.g., by the receiving node) is 512 bytes, the window size is adjusted to 500 bytes before reaching the sending node. The adjustment amount may be based on an estimated size increase resulting from converting from IPv4 to IPv6. In this example, the window size is decreased by 12 bytes since a conversion from IPv4 to IPv6 where one 4 byte IPv4 address is changed to a 16 byte Ipv6 address has an associated size difference of 12 bytes. In a specific embodiment, actual changes in packet size may tracked and the adjusted size indicator may be dynamically based on such tracked changes. In other embodiments, the changes in packet size are predicted, and the adjusted size is preemptively changed as needed.

A packet size control method allowing reduction in the period of time during which transmission is in a blocked state is disclosed. The size of a packet to be sent is determined depending on a measured round trip time (RTT), a current bandwidth of the data link layer, and a current congestion window size. First, a maximum segment size (MSS) is obtained based on the measured RTT and the current bandwidth of the data link layer using a table obtained by data transfer simulation. Thereafter, the obtained MSS is corrected using the current congestion window size. And the correct MSS is used to determine the final segment of data to be sent.

The present disclosure is directed generally to systems and methods for changing an application layer transaction timeout to prevent Denial of Service attacks. A device intermediary to a client and a server may receive, via a transport layer connection between the device and the client, a packet of an application layer transaction. The device may increment an attack counter for the transport layer connection by a first predetermined amount responsive to a size of the packet being less than a predetermined fraction of a maximum segment size for the transport layer connection. The device may increment the attack counter by a second predetermined amount responsive to an inter-packet-delay between the packet and a previous packet being more than a predetermined multiplier of a round trip time. The device may change a timeout for the application layer transaction responsive to comparing the attack counter to a predetermined threshold.

Provided are apparatuses and methods for transmitting or receiving data packets in a data block in a communication network with a transport protocol. In one example, a loss tolerant TCP protocol is used in which a maximum segment size (MSS) may be adapted to a minimum granularity of a congestion window. Also, proactive forward error correction (FEC) packets may be added to a window of the data block. The number of proactive FEC packets may be determined, for example, based on an estimate erasure rate. In addition, reactive FEC packets may be added to the data block. Also, a receiver may receive data packets in a data block and process a selective acknowledgment (SACK) responsive to the data packets received.

Methods and apparatus for secure network communication in a Secure Sockets Layer (SSL) by avoiding small Transmission Control Protocol (TCP) packets are provided. For some embodiments, these small packets may be avoided by adjusting a maximum segment size (MSS) used in transmissions between an encryption engine and a server to compensate for the amount of overhead added by the encryption process.

Systems and methods of propagating maximum segment size and path maximum transmission unit of network paths between an intermediary device of a cluster with a plurality of destinations are described. A first core of a node including multiple cores and intermediary to a client and a plurality of servers may receive a response to a packet transmitted to a destination indicating that the packet has a size greater than a MTU of a network path between the node and a destination. The first core identifies the MTU of the network path and determines that the identified MTU is different than an MTU used by the first core. The first core replaces the MTU stored in an entry corresponding to the destination in a PMTU table maintained with the identified MTU. The first core transmits, to other cores of the node, the identified MTU to update each core's PMTU table.

Provided are apparatuses and methods for transmitting or receiving data packets in a data block in a communication network with a transport protocol. In one example, a loss tolerant TCP protocol is used in which a maximum segment size (MSS) may be adapted to a minimum granularity of a congestion window. Also, proactive forward error correction (FEC) packets may be added to a window of the data block. The number of proactive FEC packets may be determined, for example, based on an estimate erasure rate. In addition, reactive FEC packets may be added to the data block. Also, a receiver may receive data packets in a data block and process a selective acknowledgment (SACK) responsive to the data packets received.

A storage processor is interposed between initiators and storage targets, such as storage appliances or storage devices in a storage network. The storage processor presents a target interface to the initiators and an initiator interface to the targets, and the storage processor transparently intercepts and processes commands, data and/or status information (such as iSCSI R2T and data PDUs) sent between the initiators and the targets. The storage processor presents a virtual device to the initiators and transparently implements the virtual device on the targets, such as a RAID-1. The storage processor negotiates acceptable operational parameters, such as maximum segment size, with the initiators and targets, such that the storage processor can pass data received from the initiators to the targets, without excessive data buffering. Consequently, when an initiator issues a write command, the storage processor is able to forward each segment of data received from the initiator to the appropriate target(s), without first buffering all segments of the write command.

Provided are apparatuses and methods for transmitting or receiving data packets in a data block in a communication network with a transport protocol. In one example, a loss tolerant TCP protocol is used in which a maximum segment size (MSS) may be adapted to a minimum granularity of a congestion window. Also, proactive forward error correction (FEC) packets may be added to a window of the data block. The number of proactive FEC packets may be determined, for example, based on an estimate erasure rate. In addition, reactive FEC packets may be added to the data block. Also, a receiver may receive data packets in a data block and process a selective acknowledgment (SACK) responsive to the data packets received.

One embodiment of the present invention provides a system that facilitates offloading message segmentation from a central processing unit onto a network interface card. The system operates by first receiving a TSO-send message at the network interface card, wherein the TSO-send message contains information about the message to be sent. Next, the system uses a header address from the TSO-send message to access a message header from memory using remote direct memory access. The system then uses a payload address from the TSO-send message to access a payload from memory that contains message data using remote direct memory access. Finally, the network interface card segments the payload into a set of maximum segment size (mss) segments and transmits the set of mss segments on the network.

A session relay device which can reliably send a data packet resent from a source to a destination without the need for reconfiguring and dividing a segment is supplied. Session relay device 110, adapted to be disposed between terminals for transmitting and receiving data as packets to which sequence numbers representative of the order of segments to be transmitted are assigned, includes session relay section 110-3 that relays data transmitted as packets between a first session opened between session relay device 110 and a terminal on a transmission side and a second session opened between session relay device 110 and a terminal on a reception side. Session relay section 110-3 receives the retransmitted segment from a terminal on the transmission side, updates a maximum segment size of the second session with the segment size of the retransmitted segment, and transmits the retransmitted segment to a terminal on the reception side.

A system, apparatus, and method selectively provides content compression to a client based, in part, on whether the network connection from the client is determined to be a high latency, low-bandwidth connection. The present invention gathers one or more network metrics associated with the connection from the client. In one embodiment, the metrics include estimated TCP metrics, including smoothed round trip time, maximum segment size (MSS), and bandwidth delay product (BWDP). These estimated network metrics are employed to make an application layer decision of whether the client connection is a high latency, low-bandwidth connection. If it is, then content may be selectively compressed virtually on the fly for transfer over the network connection. In one embodiment, the selective compression uses a content encoding compression feature of the HTTP protocol standard.

The virtual Server (vServer) of an intermediary device deployed between a plurality of clients and services supports parameters for setting maximum segment size (MSS) on a per vServer/service basis and for automatically learning the MSS among the back-end services. In case of vServer/service setting, all vServers will use the MSS value set through the parameter for the MSS value set in TCP SYN+ACK to clients. In the case of learning mode, the backend service MSS will be learnt through monitor probing. The vServer will monitor and learn the MSS that is being frequently used by the services. When the learning is active, the intermediary device may keep statistics of the MSS of backend services picked up during load balancing decisions and once an interval timer expires, the MSS value may be picked by a majority and set on the vServer. If there is no majority, then the highest MSS is picked up to be set on the vServer.

A method, system, and computer program product for negotiating a smart maximum segment size of a network connection for a data transfer. A client request to initiate a network connection, which includes a first maximum segment size, is received at a server. The server calculates a second maximum segment size, wherein at least one of the first maximum segment size or the second maximum segment size is a cache line size aligned Ethernet frame size, or smart maximum segment size. The server determines the smaller of the first and second maximum segment sizes and sends the second maximum segment size to the client. The client then selects the smaller of the first and second maximum segment sizes, and sends an acknowledgement to the server to complete the connection. The smaller of the first and second maximum segment sizes is used for the network connection and subsequent data transfer.

The embodiment of the invention provides a method and a device for determining the maximum capacity of a message, so as to prevent an NP (Network Processor) in a base station from performing fragmentation and reassembly on the message and increase the transmission efficiency of the base station. The method comprises the following steps that the message sent by a sending end is received; when the received message is determined as a transmission control protocol (TCP) message containing a maximum segment size (MSS) value, the MSS value of the message is compared with a preset capacity threshold; if the MSS value of the message is greater than the preset capacity threshold, the MSS value of the message is adjusted to the preset capacity threshold; and the TCP message carrying the adjusted MSS value is sent to a receiving end.

A method for performing Remote Direct Memory Access (RDMA), the method including creating Direct Data Placement (DDP) segments of data using a Maximum Segment Size (MSS), called the original MSS, using the DDP segments as a payload for TCP (Transport Control Protocol) segments, TCP transmitting data including the TCP segments, and if the original MSS has changed to a new MSS, temporarily halting DDP segmentation until outstanding data has been acknowledged.

The invention provides a method and a device for path maximum transmission unit (PMTU) learning. In a transmission control protocol (TCP) connection establishment process, forwarding equipment modifies a value of a maximum segment size (MSS) option in a Syn message, so that the value of the MSS option in the Syn message finally can be modified into the minimum of maximum transmission unit (MTU) values of all forwarding equipment in a transmission path; moreover, a final value of the MSS option in the Syn message is also carried by a Syn+Ack message and an Ack message, so that communication equipment can learn a PMTU by utilizing the value of the MSS option in the TCP connection establishment process, and is not required to learn the PMTU hop by hop in a communication process after the establishment of TCP connection; and therefore, PMTU learning speed can be increased, and a network bandwidth occupied by the PMTU learning can be saved. A change in the MTU value of the forwarding equipment also can be adapted by modifying a value of an MSS option in the Syn+Ack message by the forwarding equipment.

A packet transfer apparatus includes an MSS option rewrite unit and packet fragmentation unit. The MSS option rewrite unit determines a first maximum segment size used in a transport layer between a transmitting hosts and the packet transfer apparatus on the basis of path information between the transmitting hosts and the packet transfer apparatus, and notifies the transmitting hosts of the first maximum segment size. The MSS option rewrite unit determines a second maximum segment size used in a transport layer between a receiving hosts and the packet transfer apparatus on the basis of path information between the receiving hosts and the packet transfer apparatus, and notifies the receiving hosts of the second maximum segment size.

There is provided a solution in which a wireless node is caused to configure a plurality of transport layer protocol streams for a communication with another node via at least one communication path, wherein each transport layer protocol stream has a different maximum segment size; monitor at least one performance parameter of each communication path between the wireless node and the other node; and select at least one transport layer protocol stream for the communication on the basis of the monitoring.

The invention provides a synchronize message transmitting method, a synchronize message transmitting device and network equipment. The synchronize message transmitting method comprises the following steps of: transmitting a synchronize confirmation message to a client after the synchronize message transmitting device receives a first synchronize message transmitted by the client; receiving a first confirmation message transmitted by the client aiming at the synchronize confirmation message; generating a second synchronize message if the first confirmation message is determined to be a legal message, and setting a value of a maximum segment size (MSS) option of the second synchronize message according to a confirmation number of the first confirmation message; and transmitting the second synchronize message with the set value to a server. Therefore, the MSS of the message transmitted by the server to the client is set to be a value of the MSS option of the second synchronize message through the server, and the problem that SYNCOOKIE cannot save the value of the MSS option of the SYN message, so that length of the message transmitted by the server to the client exceeds a maximum transmission unit (MTU) allowed by a virtual private network (VPN) channel so as to be discarded by a VPN gateway is solved.

The invention provides a TCP (Transmission Control Protocol) bypass blocking method and device. The method comprises the steps of obtaining a negotiation maximum segment size MSS value based on an obtained TCP handshake message transmitted between a client and a server; constructing reset RST messages according to a suspicious message and the negotiation MSS value when the suspicious message is monitored; and sending the reset RST messages to the client and the server, thereby blocking the suspicious message, wherein when the suspicious message is the message sent by the client, the RST messages sent to the client comprise multiple RST messages of which SEQ values are successively increased by at least one negotiation MSS value, and when the suspicious message is the message sent by the server, the RST messages sent to the client comprise multiple RST messages of which SEQ values successively is increased by at least one negotiation MSS value. According to the method and the device, the multiple RST messages can be sent to the client and the server, and therefore, the problem that in the prior art, the blocking success rate is low can be solved.

The embodiment of the invention discloses a flow statistical method which comprises the following steps of: acquiring an MSS (Maximum Segment Size) value contained in uplink data stream; calculating an MSS value of downlink data stream corresponding to the uplink data stream according to the MSS value of the uplink data stream; and calculating the network flow of the downlink data stream according to the MSS value of the downlink data stream. The embodiment of the invention correspondingly provides flow statistical equipment. The method and the equipment provided by the embodiment of the invention can be used for realizing that flow analysis equipment used for analyzing uplink data stream under an asymmetric route scene can perform statistics on the network flow of the downlink data stream.