Nippon Telegraph and Telephone Corporation

Semiconductor Technology Academic Research Center

Katsuya Minami

Tatsuya Fukui

Satoshi Ikeda

Satoshi Narikawa

Takashi Watanabe

Yuki Sakaue

Shunsuke Saruwatari

Kazuhiko Kinoshita

Ryota Shiina

Hiroyuki Furukawa

Kunio Hato

Muneyoshi Suzuki

Takahito Kirihara

Masahiro Maruyoshi

Koso Murakami

Hideki Tode

An object is to provide a network management system and the like capable of being introduced into an existing network to ascertain an instantaneous traffic variation in the network. The scheme of the present invention uses a shaping function included by each edge apparatus. The shaping function controls packet transmission in a millisecond order. The network management apparatus according to the present invention adds up the amount of transmitted packets for each control period reported by each edge apparatus and estimates this as an instantaneous traffic amount in the network. In the scheme, it is only necessary to add one network management apparatus to an existing network and to cause each edge apparatus to report the amount of transmitted packet to the network management apparatus.

Network management systems, edge devices, network management devices, and programs

An object is to provide a communication system in which there are no restrictions on a communicable area and it is not necessary to install communication software on a wireless device. A communication system according to the present invention is configured so that the functions of a wireless access point are separated into a front-end unit on a wireless terminal side and a back-end side on the Internet side, radio signal processing functions supporting a wireless scheme of the wireless terminal are deployed only on the back end, and only relatively simple processing functions such as E/O conversion are deployed on the front end near the wireless terminal

Communication system

An object is to provide a communication apparatus, a communication method, and a program capable of avoiding an increase in network load when input traffic continues to be large and a communication delay when input traffic is very small. A communication apparatus according to the present invention prepares three token buckets and can transfer, discard, or hold a packet in accordance with the amount of tokens in each token bucket. This enables the communication apparatus to operate so as not to exceed a set maximum bandwidth when large traffic is received for the delay guarantee shaping. Further, When the maximum bandwidth is exceeded, the communication apparatus can select whether to discard a packet to prioritize a delay guarantee or to hold a packet to prioritize no loss of packets. Furthermore, the communication apparatus can immediately transmit a packet without increasing a communication delay when input traffic is very small.

Communication apparatus having delay guarantee shaping function

The present disclosure aims to make it possible to simultaneously establish communication between many freely-selected radio terminals without using a complex relay network or a plurality of radio relays. The present disclosure is a communication network system including: a plurality of optical-radio converters-to-that convert a radio signal and an optical fiber radio signal into each other; and a path controller that is connected to the plurality of optical-radio converters-to-through optical fiber transmission lines-to-, receives input of an optical fiber radio signal transmitted from any optical-radio converter of the plurality of optical-radio converters-to-from the optical fiber transmission line connected to the optical-radio converter, and outputs the optical fiber radio signal to the optical fiber transmission line connected to a set optical-radio converter of the plurality of optical-radio converters-to-

Communication network system

In a ring redundant communication path control method, each of transfer apparatuses periodically transmits an inspection frame for inspecting a communication path, detects a failure of the communication path when the inspection frame is not received for a fixed time, transmits a non-arrival notification frame for notifying that the inspection frame has not arrived yet, and detects a failure of the communication path when the non-arrival notification frame is received. Each of the transfer apparatuses closes, when a failure is detection, a port in which the failure is detected, transmits an open command frame for commanding to open a normally closed port from the other port other than the closed port, transfers an open command frame when the open command frame is received, and opens the normally closed port when the other port other than the closed port in which the failure is detected, the port in which the open command frame is detected, or the other port configuring a ring redundant communication path same as that of the port is the normally closed port.

Ring-shaped redundant communication path control method

An output port circuit is provided for a router apparatus which routes and transmits a received packet. Each flow is constituted by continuous packets and belongs to a bandwidth-guaranteed class or a best-effort class. A controller controls storage and reading of a packet into and from a storage unit. Upon allocating a basic volume that is a criterion of a memory size stored in the storage unit to each flow to which the packet to be transmitted belongs, the controller manages the basic volume of each flow of the packet belonging to the bandwidth-guaranteed class by individually allocating the basic volume by the memory size required by each flow, and manages the basic volume of each flow of the packets belonging to the best-effort class by collectively allocating the memory size obtained by subtracting a sum of respective basic volumes allocated to the bandwidth-guaranteed class from an entire memory size.

Router apparatus provided with output port circuit including storage unit, and method of controlling output port circuit of router apparatus

Growing community of inventors

Chiba-ken, Japan

Katsuya Minami