Problem $2$

Consider the WAN formed by the interconnection of three $4-$port switches as shown below. The switch ports are connected with bidirectional ainks shown by the single lines. Date Terminal Equipment $($DTE$)$ are attached to the switches as shown.

PDUs coming in on a port are examined and forwarded based on the PDU VCI and the port on which the PDU entered the switch. The network switches are programmed with routing tables with entries as shown below.

$($a$)$ DTE $1$ sends a PDU wich VCI $=1$ to switch $1.$ Trace the path this PDU takes through the network by drawing a solia line in che diagram above, and Indicating the VCI the PDU acquires as it traverses the network to the destination.

$($b$)$ Repeat $($a$)$ for the case where DTE $1$ sends a PDU with VCI $=2$ to swicch $1.$ Use a dashed Jine for this case.