Communication device and control method for frame transfer

Patent metadata

Field	Value
Publication number	US-10715445-B2
Application number	US-201815919521-A
Country	US
Kind code	B2
Filing date	Mar 13, 2018
Priority date	Sep 14, 2015
Publication date	Jul 14, 2020
Grant date	Jul 14, 2020

Abstract

In a communication device, a frame received via a port on the reception side is transmitted via a port on the transmission side. A first detector detects linkup of a port on the transmission side. When linkup is detected, a second detector detects a state closer to an overflow of a transmission buffer that accumulates a frame to be transmitted via the port on the transmission side. When a state closer to an overflow is detected, a control unit executes flow control via a port on the reception side when no transmission failure is detected in the port on the transmission side, and the control unit determines non-execution of flow control via the port on the reception side when a transmission failure is detected in the port on the transmission side.

First claim

What is claimed is:

1. A communication device in which a frame received via a first interface is transmitted via a second interface, the communication device comprising:
a memory storing a program that, in response to execution, causes a Central Processing Unit (CPU) to implement a configuration including:
a first detector that detects linkup of the second interface;
a second detector that detects, in response to the first detector detecting the linkup, a state closer to an overflow of a buffer that accumulates a frame to be transmitted via the second interface; and
a control unit that executes flow control via the first interface in response to the second detector detecting the state closer to the overflow and in response to a difference between a value of a reception counter in the first interface and a value of a transmission counter in the second interface being smaller than a threshold and, accordingly no transmission failure is detected in the second interface,
wherein, in response to the second detector detecting the state closer to the overflow and in response to the difference between the value of the reception counter in the first interface and the value of the transmission counter in the second interface being greater than or equal to the threshold or the difference being consecutively a threshold value or greater and, accordingly, a transmission failure being detected in the second interface, the control unit determines non-execution of flow control via the first interface, and
wherein the reception counter and the transmission counter count a number of frames received or transmitted for a same period of time.

2. The communication device of claim 1 , wherein, in response to the control unit determining non-execution of flow control via the first interface, the control unit continues the non-execution of the flow control until the communication device is restarted.

3. A control method for a communication device in which a frame received via a first interface is transmitted via a second interface, the control method comprising:
detecting linkup of the second interface;
detecting, in response to the linkup being detected, a state closer to an overflow of a buffer that accumulates a frame to be transmitted via the second interface;
executing flow control via the first interface in response to the state closer to the overflow being detected and in response to a difference between a value of a reception counter in the first interface and a value of a transmission counter in the second interface being smaller than a threshold and, accordingly, no transmission failure is detected in the second interface; and
determining non-execution of flow control via the first interface in response to the state closer to the overflow being detected and in response to the difference between the value of the reception counter in the first interface and the value of the transmission counter in the second interface is greater than or equal to the threshold or the difference being consecutively a threshold value or greater and, accordingly, a transmission failure being detected in the second interface,
wherein the reception counter and the transmission counter count a number of frames received or transmitted for a same period of time.

Assignees

• Jvc Kenwood Corp

Inventors

• Owada Yasujiro
• Ohtani Kiyoharu

Classifications

• H04L47/32 Primary

  by discarding or delaying data units, e.g. packets or frames · CPC title

• H04L2012/445

  with switching in a hub, e.g. ETHERNET switch · CPC title

• H04L47/30

  in combination with information about buffer occupancy at either end or at transit nodes · CPC title

• H04L47/122 Primary

  by diverting traffic away from congested entities · CPC title