Question

Calculate the latency (from first bit sent to last bit received) for the following:

(a) 100-Mbps Ethernet with a single store-and-forward switch in the path and a packet size of 12,000 bits. Assume that each link introduces a propagation delay of 10 µs and that the switch begins retransmitting immediately after it has finished receiving the packet.
(b) Same as (a) but with three switches.
(c) Same as (a), but assume the switch implements "cutthrough" switching; it is able to begin retransmitting the packet after the first 200 bits have been received.

Answer 1

260us, 520us and 166us

Step-by-step explanation:

a) Given,

Transmission time

= 12000bits/100MBPS

= 12000/100×10 raised to power 6

= 120us

Packet reaches at switch

=120+10

=130us

Then from switch to destination =130

Therefore, total latency,

= 130+ 130

= 260us

Please kindly go to attachment for the step by step solution of b and c.