Software Defined Networking is an attempt at providing a programmable network protocol that can be used to virtualize entire network infrastructures. By virtualiziing your network infrastructure Open Flow will someday allow us to overcome network vendor compatibility issues surrounding how routing protocols are implemented and also to manage layer 2 and layer 3 network constructs such as SONET and IP using a single protocol without worrying about a Layer three IP addresses or Layer Two Virtual Circuit numbers. At layer three Open Flow seems like a protocol that is used to implement distributed policy based routing at layer two i see no current equivalent tool or tech.
SDN Advantages as i see it (note my knowledge of SDN is nascent)
1: Easier to Manage End to End Infrastructure Elements at layer two and three (Reduce Opex?)
2: Network equipment prices should fall since SDN/Open Flow relies on a central controller to push policies to devices (Capex reduction).
3: Enhance Traffic Engineering at Layer two without the need for spanning tree.
4: Engineers can now acquire knowledge instead of studying vendor specific equipment commands
5: Being Open Source there will be less RFC interpretation discrepancies between vendors (Yes OSPF is implemented differently by vendors trying to enhance/lock out the competition)
Questions for the Experts:
1: While being an advantage, isn’t the programmability of Software Defined Networking also a way of adding complexity to current networking paradigm,programming is viewed as being complex imagine if we could create macros for all our current tasks it would reduce future work but would be difficult and time consuming upfront.
2: The SDN controller will control traffic flows by adding and removing entries from flow tables embedded in our switches and routers. By using a central controller will this not add latency to policy execution in large infrastructres ?
3: Will Open Flow replace current Layer 2 and layer three protocols such as MPLS, BGP and OSPF ?