Kdd Corporation

Kddi Corporation

Ddi Corp.

Toshihiko Kato

Toru Hasegawa

Akira Idoue

Teruyuki Hasegawa

Akio Ishikawa

Tomohiko Ogishi

Kouhei Yoshiizumi

Osamu Maeshima

Yutaka Miyake

A WAP (Wireless Application Protocol) analyzer located on a transmission line between communication apparatuses using WAP. A WAP packet includes at least one WTP-PDU (Wireless Transaction Protocol&#x2014;Protocol Data Unit). The WAP analyzer comprising, database () for storing state-transition specification data that define a state-transition with a cause-and-effect relationship between WTP-PDUs, states of a WTP layer, primitives between the WTP layer and WSP (Wireless Session Protocol) layer, and states of the WSP layer, based on WAP specification, means () for extracting the WTP-PDUs from the WAP packets, and means () for estimating the state-transition of the WTP layer and the WSP layer, to the apparatus that received one of the WTP-PDUs and subsequently sent other of the WTP-PDUs, for each pair of a sender and a receiver.

WAP analyzer

As shown in FIG., when the SYN segment is detected, the amount of transmitted segment from the side which sent the detected SYN segment is obtained by counting the continuously detected DATA segments for collecting the traffic in a certain direction where it is impossible to directly capture the traffic. Further, the amount [ini_sdt] of the transmitted bytes from the side which sent the detected SYN segment is obtained by calculating the equation [ini_sdt]=[SEQn+LENn]&#x2212;[SEQ. Wherein, [SEQis the sequence number of the first detected DATA segment, [SEQn] is the sequence number of the last detected DATA segment and [LENn] is the user data length of the last detected DATA segment.

Method for collecting statistical traffic data

The apparatus is set on the line between the first and second computers which respectively communicates by a protocol, such as TCP, having a flow control. The delay between the first computer and a position, at which the apparatus is set, is less than the delay between the position and the second computer . The apparatus sends and receives a packet to/from the computers . The apparatus transfers to the second computer , a data packet sent from the first computer and being larger than a maximum data amount notified by the second computer . The apparatus transfers, to the first computer , a data packet sent from the second computer , but does not transfer, to the first computer , an ACK packet sent from the second computer . The apparatus generates, instead of the second computer , an ACK packet for a data packet sent from the first computer and then sends the ACK packet to the first computer . Therefore, in a case that a large delay section having exists in the line between the computers and , it is possible to perform a high speed communication on one way by only setting one apparatus

Apparatus for high speed communication on asymmetric line

A TCP gateway terminates TCP flow control and retransmission control of TCP packets which are input from a transmitter side terminal, in place of a receiver side terminal. Also, the TCP gateway transfers the packet to the TCP gateway which is located on the opposite side, by using selective retransmission procedures in a data link layer using SSCOP and by using peculiar flow control procedures. In addition, the TCP gateway provides the process of transferring the packet to the receiver side terminal in accordance with the TCP process procedures in place of the transmitter side terminal, to a plurality of TCP connections simultaneously.

TCP communication speed improving system

Growing community of inventors

Saitama, Japan

Toshihiko Kato