| 摘要 |
<p>PURPOSE:To prevent the waste of resources by adding a hand-over number to the call set request telegraphic message and by subtracting this number in a repeating node equipment and by detecting failure of call set on the basis of the subtraction result. CONSTITUTION:In case that terminal alpha of unit A performs call set for terminal beta of unit E in the data communication network constituted by node units A-E, the call set telegraphic message where hand-over number HON5 is added to call set request indication Rp, channel number (a), destination node address E, and issuance source node address A is generated from unit A and is sent to adjacent node unit B. When the destination address is not its own address, adjacent node unit B changes the channel number and subtracts 1 from HON and sends the message to next adjacent node units successively. In the node unit where HON becomes 0, failure of call set dependent upon loop phenomena of the call set request telegraphic message is detected to abandon this message, and a call set reject telegraphic message with call set reject indication Cp and the channel number added is generated and is transmitted successively through the route reverse to the request telegraphic message, and set lines are released.</p> |
