Nippon Telegraph and Telephone Corporation

Ntt Corporation

Masashi Kaneko

Kei Fujimoto

Takeshi Fukumoto

Provided is a server delay control device for a server in which an OS having a kernel is deployed. The OS includes: a ring buffer managed by the kernel; and a poll list in which information on a net device of a hardware interrupt from an NIC is registered. The server delay control device is deployed in the server and configured to receive a timer interrupt at predetermined specified intervals and monitors a packet arrival and includes: a packet arrival monitoring part configured to check the presence or absence of a packet in the poll list upon being triggered by the timer interrupt to monitor the poll list; and a packet dequeuer configured to, when a packet has arrived, reference the packet held in the ring buffer, and perform dequeuing to remove the corresponding queue entry from the ring buffer.

Server delay control device, server delay control method, and program

In a time synchronization system, a network controller sets transmission distance information on a transmission distance through which an optical signal is transmitted between transmission and receiving servers via a queueless network to a receiving server, based on network topology information. The transmitting server transmits a transmitting side current time synchronized with a reference time to the receiving servervia the queueless network. The receiving server calculates a transmission delay time between the transmission and receiving servers by dividing the transmission distance, which is based on the set transmission distance information, by light speed in the queueless network. A receiving side current time is calculated by adding the transmission delay time to the transmitting side current time.

Growing community of inventors

Musashino, Japan

Masashi Kaneko