IP SWITCHES. 1. Receive INFLOWS DATA IN

Transcription

1 IP SWITCHES 1. Receive INFLOWS

2 IP SWITCHES 1. Receive INFLOWS 2. BUFFER & Route

3 IP SWITCHES 1. Receive INFLOWS 2. BUFFER & Route 3. Transmit OUTFLOWS

4 IP SWITCHES 1. Receive INFLOWS 2. BUFFER & Route 3. Transmit OUTFLOWS TRAFFIC SHAPING AFFECTS HOW MUCH BUFFER AN IP SWITCH NEEDS

5 THE PRINCIPLE IS ANALOGOUS TO WATER FLOWING IN & OUT OF A BUCKET WATER IN ANALOGY WATER OUT

6 THE PRINCIPLE IS ANALOGOUS TO WATER FLOWING IN & OUT OF A BUCKET 1. Both have INFLOWS WATER IN WATER OUT

7 THE PRINCIPLE IS ANALOGOUS TO WATER FLOWING IN & OUT OF A BUCKET 1. Both have INFLOWS WATER IN 2. Both BUFFER WATER OUT

8 THE PRINCIPLE IS ANALOGOUS TO WATER FLOWING IN & OUT OF A BUCKET 1. Both have INFLOWS WATER IN 2. Both BUFFER 3. Both have OUTFLOWS WATER OUT

9 IN THIS ANALOGY UNIFORM PACKET SPACING (NARROW TRAFFIC SHAPE) Δt 1 EQUATES TO UNIFORM WATER FLOW PACKETS Δt 2 Δt 3 Δt 4 Δt 1 Δt 2 Δt 3 Δt 4

10 WITH THE WATER/BUCKET ANALOGY IF THE WATER FLOW IS UNIFORM UNIFORM WATER FLOW

11 WITH THE WATER/BUCKET ANALOGY IF THE WATER FLOW IS UNIFORM UNIFORM WATER FLOW AND WATER ENTERING = WATER EXITING

12 WITH THE WATER/BUCKET ANALOGY IF THE WATER FLOW IS UNIFORM UNIFORM WATER FLOW AND WATER ENTERING = WATER EXITING THE BUCKET NEVER OVERFLOWS

13 WITH AN IP SWITCH IF PACKET SPACING IS UNIFORM (TRAFFIC PROFILE IS VERY NARROW)

14 WITH AN IP SWITCH IF PACKET SPACING IS UNIFORM (TRAFFIC PROFILE IS VERY NARROW) AND DATA ENTERING = DATA EXITING

15 WITH AN IP SWITCH IF PACKET SPACING IS UNIFORM (TRAFFIC PROFILE IS VERY NARROW) AND DATA ENTERING = DATA EXITING SWITCH MEMORY NEVER OVERFLOWS

16 WITH THE WATER/BUCKET ANALOGY IF THE WATER FLOW IS BURSTY NON-UNIFORM WATER FLOW

17 WITH THE WATER/BUCKET ANALOGY IF THE WATER FLOW IS BURSTY AND NON-UNIFORM WATER FLOW AVERAGE WATER ENTERING = AVERAGE WATER EXITING

18 WITH THE WATER/BUCKET ANALOGY IF THE WATER FLOW IS BURSTY AND NON-UNIFORM WATER FLOW AVERAGE WATER ENTERING = AVERAGE WATER EXITING THEN WATER LEVEL VARIES AND IF THE BUCKET ISN T BIG ENOUGH

19 WITH THE WATER/BUCKET ANALOGY IF THE WATER FLOW IS BURSTY AND NON-UNIFORM WATER FLOW AVERAGE WATER ENTERING = AVERAGE WATER EXITING THEN WATER LEVEL VARIES AND IF THE BUCKET ISN T BIG ENOUGH THE BUCKET OVERFLOWS

20 WITH AN IP SWITCH IF PACKET FLOW IS BURSTY (TRAFFIC PROFILE IS WIDE)

21 WITH AN IP SWITCH IF PACKET FLOW IS BURSTY (TRAFFIC PROFILE IS WIDE) AVERAGE DATA ENTERING AND = AVERAGE DATA EXITING

22 WITH AN IP SWITCH IF PACKET FLOW IS BURSTY (TRAFFIC PROFILE IS WIDE) AVERAGE DATA ENTERING AND = AVERAGE DATA EXITING THEN BUFFER LEVEL VARIES AND IF THE SWITCH BUFFER ISN T BIG ENOUGH

23 WITH AN IP SWITCH DROPPED PACKETS IF PACKET FLOW IS BURSTY (TRAFFIC PROFILE IS WIDE) AVERAGE DATA ENTERING AND = AVERAGE DATA EXITING THEN BUFFER LEVEL VARIES AND IF THE SWITCH BUFFER ISN T BIG ENOUGH THE BUFFER OVERFLOWS

24 AS NON-UNIFORM WATER FLOWS REQUIRE A BIG ENOUGH BUCKET TO ACCOUNT FOR WATER LEVEL VARIATION CONCLUSION

25 CONCLUSION AS NON-UNIFORM WATER FLOWS REQUIRE A BIG ENOUGH BUCKET TO ACCOUNT FOR WATER LEVEL VARIATION NON-UNIFORM DATA FLOWS (WIDE TRAFFIC SHAPES) REQUIRE ENOUGH IP SWITCH BUFFER MEMORY TO ACCOUNT FOR DATA LEVEL VARIATION WITHIN THE SWITCH

26 CONCLUSION TAKEAWAYS SUCH DEEP BUFFER MEMORY SWITCHES ARE AVAILABLE AND CAN BE SPECIFIED WHEN USING SMPTE ST WIDE TRAFFIC SHAPING USING SMPTE ST NARROW TRAFFIC SHAPING MINIMIZES SWITCH MEMORY REQUIRED NON-UNIFORM DATA FLOWS (WIDE TRAFFIC SHAPES) REQUIRE ENOUGH IP SWITCH BUFFER MEMORY TO ACCOUNT FOR DATA LEVEL VARIATION WITHIN THE SWITCH