Nippon Telegraph and Telephone Corporation

Takashi Kurimoto

Takashi Shimizu

Nobuaki Matsuura

Shigeo Urushidani

Michihiro Aoki

Takashi Miyamura

Keisuke Kabashima

Hisashi Kojima

Ichiro Inoue

Ikuo Yamasaki

Tomonori Takeda

Masahiro Goshima

An optical network has: sections for establishing optical paths; a plurality of optical edge routers for connecting external IP networks to the optical network (); and a plurality of optical cross connects, for connecting the optical edge routers by the optical paths, having switching sections with respect to an optical pulse unit. In the optical network, each of the optical edge routers has both of: (1) an optical network control instance (INSp) for maintaining topology information in the optical network and switching/signaling the optical paths; and (2) an IP network instance (INSi) for maintaining a routing table in each of the external IP networks and activating routing protocols between the external IP networks and the IP network instance. By doing this, it is possible to realize a multi-layer cooperative function and provide highly safe optical networks, etc.

Optical network, optical edge router, program thereof, cut through method, and edge router

A data transfer apparatus and a data transfer system are provided that can reduce the cost of installing communication equipment compatible with each of several dissimilar communication protocols in one exchange office and can reduce the cost of constructing the network. The data transfer apparatus includes a data reception device () that receives packets that comply with dissimilar communication protocols from upstream data transfer apparatuses (and); a content data extraction device () that extracts content data included in the packets; a line selection information storage device () that stores the line selection information for selecting communication lines that comply with dissimilar communication protocols; a line selection device () that selects the communication line compatible with content data based on the line selection information; and a data transfer device () that transfers data to downstream data transfer apparatuses (and) that are connected to the communication line that has been selected by the line selection device.

Data transfer apparatus and data transfer system

The purpose of the present invention is to provide a datagram transfer network that can operate stably by avoiding a state of congestion collapse by utilizing information derived from evaluating the impact of datagrams on the operation of the network. To achieve this objective, the results of evaluation is expressed as a preference value related to datagrams, and are inserted in the header in each datagram so that the datagrams are processed by an approach other than the methods based on arrival sequence of datagrams, when derived to the destination indicated in the header. In this approach, datagrams are protocol is controlled by priority order derived from the preference value which reflects traffic information obtained by a traffic monitoring equipment.

Traffic monitoring equipment and system and method for datagram transfer

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Tokyo, Japan

Takashi Kurimoto