COMPUTER NETWORKS-I × TCP

TCP RTT

Posted by AJ × 05:10

• Jacobson algorithm

• Another smoothed value D deviation it is the difference between the expected

and observed value |RTT-M|

• D= α D+(1- α )|RTT-M|

• Timeout interval =RTT+4*D

• The problem with retransmission answered by Karn’s algorithm

• RTT not updated for retransmitted segment timeout is doubled on each failure till

the segment gets through first time

• There is another timer called the persistence timer- it is used when the sender is made to wait due to lack of buffer space at the receiver. Once this timer goes off the sender sends the probe to find about the receiver buffer space otherwise a deadlock occurs so this timer is used to resolve the same

• The third timer is the keepalive timer- it is used for the connections which are idle for a long time suppose this timer goes off then the connection is closed