Unit $1$ Assignment

Suppose the length of each packet is L bits. Also, assume the path from a server to a client includes $N$ links each of rate $R($i$.$e$.,$ there are $N-1$ routers between the server and the client$).$

a$.$ With store$-$and$-$forward packet switching, what is the end$-$to$-$end delay to transmit one packet over the $N$ links $($ignoring propagation, processing, and queueing delays$)?$

b$.$ What is the delay if the server sends $P$ such packets back$-$to$-$back over the $N$ links?

A packet switch receives a packet and determines the outbound link to which the packet should be forwarded. When the packet arrives, suppose one other packet is halfway done being transmitted on this outbound link and three other packets are waiting to be transmitted. Packets are transmitted in order of arrival. If all packets are $2,000$ bytes and the link rate is $20Mbps,$ what is the queueing delay for the packet?

Perform a Traceroute between a source $($your computer$)$ and a destination on the same continent. $($The Traceroute diagnostic tool may have a different name on your computer, such as tracert on Windows machines.$)$

Do it twice, at different times of the day $($or different days$).$ Also, perform a Traceroute from your computer to a destination on a different continent. Again, do it twice, at different times of the day $($or different days$).$

Submit a copy $($e$.$g$.,$ screenshot$)$ of the four Traceroute outputs. Comment briefly: How many routers are there in the paths? Did the paths change between the measurements? Where do the largest delays occur?