In the example in 3.4 Virtual Circuits, give the VCI table for switch S5.

BEGINNING OF QUESTION FROM BOOK:

A to F: A4S16S24S48S55F; this path goes from S1 to S4 via S2

A to E: A5S16S33S48E; this path goes, for no particular reason, from S1 to S4 via S3, the opposite corner of the square

A to C: A6S17S33C

B to D: B4S38S17S28D

A to F: A7S18S25S49S52F

One may verify that on any one link no two different paths use the same VCI.

We now construct the actual VCI,port tables for the switches S1-S4, from the above; the table for S5 is left as an exercise. Note that either the VCI_in,port_in or the VCI_out,port_out can be used as the key; we cannot have the same pair in both the in columns and the out columns. It may help to display the port numbers for each switch, as in the upper numbers in following diagram of the above red connection from A to F (lower numbers are the VCIs):

These are the other tables:

Switch S1:

VCIin	portin	VCIout	portout	connection
4	0	6	2	AF #1
5	0	6	1	AE
6	0	7	1	AC
8	1	7	2	BD
7	0	8	2	AF #2

Switch S2:

VCIin	portin	VCIout	portout	connection
6	0	4	1	AF #1
7	0	8	2	BD
8	0	5	1	AF #2

Switch S3:

VCIin	portin	VCIout	portout	connection
6	3	3	2	AE
7	3	3	1	AC
4	0	8	3	BD

Switch S4:

VCIin	portin	VCIout	portout	connection
4	3	8	2	AF #1
3	0	8	1	AE
5	3	9	2	AF #2