Does the term switch and router makes sense in OpenFlow context

Question

I started reading up on OpenFlow recently.Traditionally by switches we mean boxes where each interface has a MAC address,where are routers are boxes where each interface has an IP address.

The controlplane of a traditional switch contains logic to learn the MAC address and RSTP implementation etc.

The control plane of a traditional router contains distributed routing protocols such as OSPF or BGP.

Once OpenFlow comes into picture and the controlling logic is shifted to the Controller does the difference between switches and routers vanish?Is this likely to drive down the prices for the traditional switches and routers.There are OpenSource controllers already available like Floodlight and OpenDayLight.

Answer 1

IMHO, 'my 2 cents'.

This is an interesting question as we might see that switches, routers, hubs and bridges etc. might just be called network devices or OpenFlow nodes. The way I see it, routers and swithces are 'basically' the same. A hardware device with input and output ports. What differentiates them are what layer they work on. Switches work on L2, Routers L3. With OF and SDN you could have a hardware box with a central controller that works on L1-L4. So yeah, the difference will in some sense vanish.

I'm working on SDN in academia at the moment, and I call everything switches in my thesis. Why? Because it switches from one input to one (or more) outputs. However (!), I'm under the firm belief that should network move towards some sort of SDN future (As it probably will, but possibly not based on OF), it will travel with the legacy attached. Meaning: Terms as switches, routers, BGP, LLDP, OSPF, CSPF, SPF, Spanning Tree, SNMP, ICMP, IGP, EGP etc etc etc will still be alive. Unless ofcourse some genius completely redesignes the Internet, and Ethernet/TCP/IP becomes obsolete, and (!) everyone jumps onboard (which is unthinkable in the near future, ref. IPv6 migration).

It might also be possible that we would start to see more and more enterprises buying merchant silicone and building their own routers/switches, or what you want to call them in an OpenFlow context. Google did this when making their internal datacenter WAN (B4, which have more traffic than their public facing WAN) SDN capable. This could drive down prices in the same way as in the eighties when people started buying microchips, installing their own OS'es and programs instead of buying closed stack solutions from IBM.

By the way, this earlier question covers a lot of what you are asking about: Flow based routing and openflow