Chapter 14 Switching Circuit Switching Packet Switching Message

Chapter 14 Switching • Circuit Switching • Packet Switching • Message Switching WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Figure 14 -1 WCB/Mc. Graw-Hill Switched Network The Mc. Graw-Hill Companies, Inc. , 1998

Figure 14 -2 WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Figure 14 -3 Circuit-Switched Network WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Figure 14 -4 Switch WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Figure 14 -5 WCB/Mc. Graw-Hill Folded Switch The Mc. Graw-Hill Companies, Inc. , 1998

Figure 14 -6 WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Figure 14 -7 Crossbar Switch WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

• How many crosspoints are needed in a single-stage switch with 40 inputs and 50 outputs? a. b. c. d. 40 50 90 2000

Figure 14 -8 Multistage Switch WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Figure 14 -9 Switching Path WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Figure 14 -9 -continued Switching Path WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Comparison • 15 -by-15 single stage crossbar – Needs ? crosspoints • 15 -by-15 multistage crossbar – Needs ? crosspoints

Comparison • 15 -by-15 single stage crossbar – Needs 225 crosspoints • 15 -by-15 multistage crossbar – Needs 78 crosspoints (30+18+30). • Three first stage switches, each with 10 crosspoints(5*2), for a total of 30 crosspoints. • Two second stage switches, each with 9 crosspoints(3*3), for a total of 18 crosspoints. • Three third stage switches, each with 10 crosspoints(5*2), for a total of 30 crosspoints.

Figure 14 -10 TDM without TSI (Time slot Interchange WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Figure 14 -10 -continued TDM with TSI WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Figure 14 -11 WCB/Mc. Graw-Hill Time-Slot Interchange The Mc. Graw-Hill Companies, Inc. , 1998

SPACE-AND TIME-DIVISION SWITCHING COMBINATIONS

Figure 14 -12 WCB/Mc. Graw-Hill TST Switch The Mc. Graw-Hill Companies, Inc. , 1998

Figure 14 -13 WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Figure 14 -14 Datagram Approach WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Figure 14 -15 Datagram Approach, Multiple Channels WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

VIRTUAL CIRCUIT APPROACH

VIRTUAL CIRCUIT APPROACH 1. SWITCHED VIRTUAL CIRCUIT 2. PERMANENT VIRTUAL CIRCUIT

Figure 14 -16 Switched Virtual Circuit WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Figure 14 -16 -continued Switched Virtual Circuit WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Figure 14 -16 -continued Switched Virtual Circuit WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Permanent virtual circuits Permanent connection for the duration of the lease

Figure 14 -17 Message Switching WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998