1. On The Break-even Point Between Cloud-Assisted and Legacy Routing
Prasun Kanti Dey
Dr. Murat Yuksel
5th IEEE International Conference on Cloud Networking
3-5 OCTOBER 2016 // PISA, ITALY

2. 1. Introduction SDN for centralization better management
Unaddressed challenges of SDN/ Traditional routers
Scalability
Cost of the router
Cisco ASR 1013 Router costs almost $30,000 ~ $50,000

3. Forwarding Task (for delegated pkts)
Evolution of Router Architectures
Forwarding Task (for delegated pkts)
OpenFlow switches already does the statistics and send them to Controller.

4. By leveraging the cloud’s memory and computation resources, can we actually remedy the routing scalability and economics issues?

5. 2. Comparative Cost Models
Let,
F = FIB size (in bits)
l = % of entire FIB in local router
d = $/bit cost of storage for DRAM
c = $/bit cloud storage cost
z = $/bit transit cost for delegated packets
𝜌(𝑙) = Traffic delegated to cloud ($/bit)
PRX
FULL FIB, F (in bits)
Storage cost, c ($/bit)
Increasing
<10% covers >90% of pkts
Increase/ decrease
Exponential decay
Decreasing function of l
Delegated Traffic
Transit cost,
z ($/bit)
Partial FIB,
l (% of entire FIB) RX
Storage cost, d ($/bit)
Traffic
FULL FIB, F (in bits) RX
Storage cost, d ($/bit)
Traffic
Traditional routing cost,
<local DRAM storage>
𝐶=𝑑𝐹
CAR cost,
<local DRAM storage> + <cloud storage> + <transit to cloud>
𝐶 =𝑑𝐹𝑙+𝑐𝐹+𝑧𝜌 𝑙

6. But, it is pretty unpredictable.
DRAM Price (d)
Exponential decrease in the overall DRAM price trend – following Moore’s Law
But, it is pretty unpredictable.
𝑑 𝑡 =1,333, 𝑒 −0.05𝑡
Source:

7. Consistent exponential decay
Cloud Price Trends
Consistent exponential decay
Source:

8. Cloud Storage Price (c)
Source:

9. Quite steady exponential decay
Transit Price (z)
Quite steady exponential decay
z 𝑡 =2,203.6 𝑒 −0.456𝑡
Source: 1.
2. Dynamic behavior of differential pricing and Quality of Service options for the Internet By P. C. Fishburn and A. M. Odlyzko.

10. 3. Cloud vs. DRAM Price
CAR may be beneficial
Break-even

11. Max local FIB size so that CAR can be economically viable.
Break-even after 96 months
Max local FIB size so that CAR can be economically viable.

12. 4. Conclusion & Future work
Presented Price trends, Proposed cost model and break-even
<70% of local FIB means, CAR is cheaper then Traditional.
Redis based cloud economics.
Cloud Service, Local Router Management cost has to be included
Must follow Net Neutrality

13. Thank you! ?