Keynote - SDN for the cloud

SDN for the Cloud - Albert Greenberg

The importance of SDNs has gradually improved in recent years. The demand for increased flexibility and room for innovation in route control and traffic engineering has led to rise of centralized control network management to meet overall network wide goals. As a result of such innovations, the emergence of cloud has led to the rise of software-defined data center networking (where each customer can gain control of entire virtual networks).

Some work in this area has led to VL2 (SIGCOMM 2009). Cloud has the right scenarios such as huge leverage, huge degree of control to make changes in the right places and high scale fault tolerant distributed systems and data management.

At Azure, the team started from scratch as they updated the hardware from optics to host to NIC to physical fabric to WAN to Edge/CDN to ExpressRoute. 

Most of the concepts presented in the papers have been put into practice in Microsoft cloud infrastructures. As a result of these improvements, modern Azure services can carry up to 1,400,000 SQL databases. Moreover, a typical Azure event hub sees as high as 1 trillion events per month. This clearly shows the level of scalability an Azure service can handle as a result of the ideas that have successfully been transferred from their research work.

He then discussed the following agenda:

**Cloud Design Principles

• Scale-out N-Active data plane
• Embrace and isolate failures
• Centralized control plane: drive network to target state

**Hyperscale Physical Networks

• VL2 -> Azure close fabrics with 40G NICS
• Outcome of > 10 years of history, with major revisions every six-months
• Scale-out
• Challenges of Scaling out
• Clos network management problem
• Solutions
• Infrastructure for graph and state tracking to provide an app platform
• Monitoring to drive out gray failures
• Azure Cloud Switch OS to manage the switches as we do servers

**Azure SmartNIC

• Use an FPGA for reconfigurable functions
• Programmed using Generic Flow Tables (GFT)
• SmartNIC can also do Crypto, Qos, storage acceleration, and more...

**Closing Thoughts

• Cloud scale, financial pressure unblocked SDN
• SDN realized through consistent application of principles of cloud design
• Microsoft Azure re-imagined networking, Created SDN and it paid off