EL ENG 122 Midterm: ee122-sp2001-mt2-Walrand-soln
Document Summary
Tcp (5 out of 20) file:///c|/documents%20and%20settings/jason%20raft0-%20spring%202001%20-%20walrand%20-%20mid%202. htm (1 of 4)1/27/2007 4:25:20 pm. Consider the situation shown in the figure below. Host a sends 1500-byte packets to host b using tcp. We assume that the hosts are very fast and have huge memories. Explain your answer carefully. (note: neglect the packet processing times; the propagation speed corresponds to 5 s/km. ) The router should be able to store (t is the propagation time) K := 2t 100 mbps = 2 1000 km 5 s/km 100 mbps = 1 mbits. To see this, assume that the buffer can store b bits. When the window size of tcp increases beyond b, say at time t, the router drops a packet and the source learns about it at time rtt, when the window size has reached approximately b + k bits. The source then divides its window size by a factor of 2 to about (b + k)/2.
