Patent ID: 9184933
Filing Date: 2015-11-10
Classification: H04L

Abstract:
1. A communication management apparatus that manages transmission of data in a network in which the communication management apparatus and one or more communication apparatuses are connected by an Ethernet cable, the communication management apparatus comprising: a token-circulation-order storing unit that stores token circulation order for circulating a token frame in the network; a token-frame receiving unit that receives the token frame and determines whether transmission right acquiring apparatus information for acquiring a transmission right next in the received token frame indicates the communication management apparatus; a token-frame transmitting unit that transmits the token frame in which: a first transmission right acquisition determination information indicating sequence numbers of the one or more communication apparatuses that can acquire the transmission right in the token circulation order is set, a second transmission right acquisition determination information indicating a specific number of frames that can be transmitted while the token frame circulates once from the communication management apparatus is set, wherein the specific number is variable based on a calculation, and the transmission right acquiring apparatus information that indicates a next transmission destination of the token frame, after the communication management apparatus, acquired from the token circulation order is set; and a data-frame-communication processing unit that performs reception processing for data frames from other communication nodes and, when the transmission right is acquired, converts data stored in the communication management apparatus into a first set of data frames in frame unit and transmits one or more of the data frames in the first set of data frames, wherein: the first transmission right acquisition determination information comprises: wherein: in the received token frame, when the second transmission right acquisition determination information is “0” and the number of transmittable frames “0” setting station information, which indicates a communication apparatus that sets the second transmission right acquisition determination information to “0”, is set: setting station information in the transmission permitted station value of the token frame, and wherein the communication management apparatus further comprises a number-of-transmittable-frames “0” setting-station storing unit, wherein a third sequence number of a communication apparatus to which the transmission right is preferentially given when the second transmission right acquisition determination information is “0” is stored in a changed-destination-information-during-priority-processing storing unit, the token-frame-receiving unit stores, when the token-frame receiving unit receives a token frame in which the transmission right acquiring apparatus information indicates the communication management apparatus and the second transmission right acquisition determination information is “0”, contents of the number-of-transmittable-frames “0” setting station information in the number-of-transmittable-frames “0” setting-station storing unit, and the token-frame transmitting unit sets, in the transmission permitted station value, the third sequence number stored in the changed-destination-information-during-priority-processing storing unit.