The inactivity timer. An enabled inactivity timer (Ti) periodically tests the viability of the network media. The timer setting applies to all the clients on the target LAN, not to individual clients. The timer interval indicates how quickly a failure of the network media can be detected when the connection is quiescent. If the Ti timer times out, a supervisory poll frame is sent over the connection. The T1 response, or reply, timer clocks the supervisory poll. If the T1 timer times out, the supervisory poll is retransmitted. OSA can retransmit a supervisory poll up to 8 times. If no response is received after the last retransmission, the link is declared inoperative, and the S/390 program issues a message. The value is represented in ticks. The value will either be zero, or in the range of 2 to 750. Each tick equals .12 of a second.