OpenStack Summit: SDN Switches Become Low Cost Linux Boxes?
The VAR Guy is at OpenStack Summit and he's starting to drink the Kool-Aid. Customers like Best Buy, Comcast and Hubspot say they are deploying the cloud computing platform. But now, the conversation is shifting to networking in the cloud — a software defined networking (SDN) primer. Leading the conversation: Ben Cherian, chief strategy officer at Midokura, a startup focused on network virtualization. His key point: SDN (using Overlay Solutions) will allow switches to be far more like commodity Linux servers — giving customers the ability to scale and manage their networks far more effectively.
Not by coincidence, Midokura today announced availability of MidoNet, which virtualizes the network stack for cloud platforms, such as OpenStack. The goal, like so many other cloud initiatives, is to reduce CapEx expenses and help customers focus more on OpEx.
"The current state of networking in the cloud is too manual," said Cherian. The object of SDN, therefore, is automation. Cherian offered a great metaphor, describing how the phone switching system in telecom started with manual switchboard operators then shifted to an electromechanical switching system invented by Almon Strowger.
When you do anything at scale, you need an abstraction layer — similar to how writing for comptuters went from machine languages to higher-level programming languages, said Cherian. In the SDN world, you need a controller that minipulates the traffic across routers appropriately.
He sees three categories for SDN. They include:
- IaaS cloud for cloud services providers and enterprises. Examples include Midokura, VMware/Nicira and Nuage.
- Fabric which includes Juniper Qfabric, NEC Programmable Flow and Big Switch. Here, everything looks like one big switch.
- Carrier/WAN approach offers a hybrid control plane. Examples include Google.
IaaS Cloud Networking requirements, he said, include:
- Layer 2 switching isolation
- Layer 3 routing isolation
- A scalable control plane
- NAT (floating IP)
- Stateful L4 firewall
- VPN (IPSec)
- BGP gateway
- REST API
- And integration with cloud management platform like OpenStack and Cloud Stack
Cherian then rattled off a range of challenges facing VARs, integrators and service providers as they seek to deploy SDN solutions. For instance, if you use an OpenFlow Fabric, you will find it's not scalable, not fast enough to update and there's no atomicity of updates, he asserted. "They're not good for IaaS cloud virtual networking. It's not good enough for cloud virtual networking."
Cherian believes most strongly in Edge to Edge IP Overlays. Here you use IP encapsulation rather than isolation using VLANs.True confession: The VAR Guy doesn't quite understand the pros and cons on this point and will defer to techies in the audience for their reality check…
Market Trends Supporting Overlay Solutions
- Packet processing on x86 CPUs (at edge); here the numer of cores in servers are increasing fast.
- Cheap IP switches are emerging from Broadcom, Intel (Fulcrum Micro), and Marvell.
- Plus ODMs (Quanta, Accton) starting to sell directly.
- "Switches are becoming just like Linux boxes."
The overlay solution, he concluded, allows network traffic to get delivered in a faster manner using fewer network hops. "The logic is all within our system. This is how we believe the network can scale. The intelligence in a router has been spread across the cloud, essentially creating a grid router."
Sounds promising. And for most VARs, it sounds like future talk. But the future sounds like it's approaching fast at the OpenStack summit….