What is jam? - Definition from Whatis.com

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jam

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jam

In an Ethernet network, a jam is a signal from one device to all other devices that a collision has occurred. Specifically, the device was trying to send a frame while another device was also trying to put a frame on the line). The jam signal results in additional collisions in any other frames in process of being put on the line and warns non-transmitting devices to wait. Effectively, a jam provides a way to force all devices to restart any bids to get control of the line.

Related glossary terms: 10-high-day busy period (10HD busy period), maximum transmission unit (MTU), CRC-4 (Cyclic Redundancy Check 4), TCP/IP (Transmission Control Protocol/Internet Protocol), OpenNMS (Open Network Management System), maximum segment size (MSS), network operations center (NOC) , ACK, loopback test, running disparity (RD)

This was last updated in August 2006

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