A mobile host (MH) is connected to a WLAN access network that uses MIP for mobility support. Consider that the RTTs between MH and HA are 0.3s while RTTs within a L2 subnet are 80ms.. A CN and the MH establish a bi-directional VoIP session (via UDP/IP) with voice-data rate of 16kb/sec transmitted in 40 packets per second. Consider for simplicity that the MH as well as the CN always send voice-data (no silence periods).

a) What are the (downstream) hand-over delays (min, max, average) when the MH changes IP address due to mobility? Assume thereby that no Layer 2 triggers are used and the periodic interval for agent advertisements is set to 3 seconds. The WLAN Layer-2 handover by itself should be assumed to take 500ms.

b) How much do the hand-over delays improve when Layer-2 triggers (Agent Solicitations) are used?

c) Compute the number of lost packets of the down-stream VoIP stream during these two hand-over scenarios.

d) The user of the mobile node becomes very nervous and walks quickly from one room to the other and back, changing rooms every 30 seconds. Compute the average downstream packet loss ratio.