Nippon Telegraph and Telephone Corporation

Yokogawa Electric Corporation

Hiroshi Shimizu

Daisuke Hayashi

Shinji Iio

Morio Wada

Masayuki Suehiro

Hirotoshi Kodaka

Yasukazu Akasaka

Shun Sugimoto

Akira Miura

Akira Toyama

Tsuyoshi Yakihara

Chie Sato

Katsuya Ikezawa

Tadashige Fujita

Toshimasa Umezawa

Kanji Tatsumi

Toshiyasu Izawa

When an SIP server receives a call signal addressed to a callee side terminal, the SIP server transmits a warning signal to the callee side terminal before transmitting the call signal to the callee side terminal when an international call identifier indicating that the call signal passes through a foreign country is set in the call signal. In addition, when the SIP server receives the call signal addressed to the callee side terminal, the SIP server includes a warning that the caller number is disguised in a warning signal when an international call identifier indicating that the call signal passes through a foreign country is set in the call signal and the caller number of the call signal is a number from a country in which the callee side terminal is located.

Call alert device, call alert system, call alert method, and call alert program

The present invention suppresses the number of connections from another network, and reduces the load on call processing apparatuses in a local network. An ENUM serverincludes: a congestion detection unitthat collects traffic information regarding calls that include call destination numbers from call processing apparatuses in the local network, calculates a call amount per unit time for each call destination number, and stores the call amounts per unit time as calculated call amount information, and also extracts a call destination number included in an ENUM query received from the other network, references the calculated call amount information, and determines that calls to the call destination number are in a congested state if the call amount regarding the call destination number exceeds a predetermined threshold value; a limit processing unitthat, if it was determined that the call destination number included in the ENUM query is in the congested state, determine whether or not the ENUM query is to be a limit target based on predetermined limit processing; and a signal response unitthat, if it was determined that the ENUM query is a limit target, generates an ENUM answer that indicates connection unavailability, and transmits the ENUM answer to the other network.

ENUM server and congestion control method

Disclosed is a repeater including: a recognizing unit to recognize a destination address of an optical packet from the optical packet which includes the destination address assigned in unit of bit and a bit indicating whether or not a plurality of destination addresses are assigned; an optical splitting unit to split the optical packet into a plurality of optical packets; and selecting units to select transmission channels for the split optical packets on the basis of recognition results by the recognizing units, respectively.

Repeater and optical communication system

There is provided a PD-TIA module that can be used for recognition of an address of an optical packet signal in a system having variation in mark rate all the time, such as an optical packet communication system. An optical communication module comprises a photoelectric converter for converting an optical signal into a current signal, a current/voltage conversion means connected to the photoelectric converter, for converting the current signal into a voltage signal, and a limiting amplifier for receiving and amplifying an electric signal subjected to voltage conversion by the current/voltage conversion means while comparing the electric signal as amplified with a predetermined threshold value, thereby outputting a signal for '0' or '1'.

Optical packet communication device with an applied negative voltage for canceling an offset voltage

Growing community of inventors

Musashino, Japan

Hiroshi Shimizu