Question

P2. Suppose two packets arrive to two different input ports of a router at exactly the same time. Also suppose there are no other packets anywhere in the router. a. Suppose the two packets are to be forwarded to two different output ports. Is it possible to forward the two packets through the switch fabric at the same time when the fabric uses a shared bus? b. Suppose the two packets are to be forwarded to two different output ports. Is it possible to forward the two packets through the switch fabric at the same time when the fabric uses switching via memory? c. Suppose the two packets are to be forwarded to the same output port. Is it possible to forward the two packets through the switch fabric at the same time when the fabric uses a crossbar? sr2jr

Answer 1

Answer

a: No, it is not possible to send both packet at a time.

Explanation:

In bus topology network, only one packet can be sent at a time. Therefore in it is not possible to forward two packets at the same time.

b. No, It is not possible to read/write two or more different memory locations at the same time.

Explanation:

As the system has shared bus topology, therefore it is not possible to read/ write on multiple locations of memory locations.

c. No, it is not possible to send two data packets at the same time on same output port.

Explanation:

Crossbar is device used to send multiple packets at the same time at different locations although it cannot send multiple packet at same location at the same time.