explain persistence timer to deal with the

Question

Explain Persistence timer?

• To deal with the zero-size windows
• What if a receiver advertises that the window size is 0 (by sending ACK) and this ACK is lost?

- ACK are not acknowledged in TCP

• Start persistence timer

- When this goes off send a probe (1 byte of data)

- It is set to the retransmission time & doubled every time a response is not received (until 60 s, then sent every 60 s)