SDN and SmartNIC

SDN or programmable network is quickly being split into three separate problems. First is programmable management plane, second is programmable control plane and programmable data plane. A lot of time is spent on discussion of programmable management and control. But very little time is spent on programmable data plane.

Whatever overlay (over L2 or L3) is used for multi-tenancy, unless all the tenants are in the same host, the packet needs to leave the host. This host interfaces with underlying fabric using a NIC of variable complexity. Today the fabric is not multi-tenant and NIC is not really programmable.

The multi-tenant fabric is a focus of academic research. As always they will come up with a new tag that needs to be inserted after existing fabric tags. But its adoption will require the NIC based programmable silicon. This NIC needs be truly programmable (in  a programmable FPGA sense of the word and not SR-IOV VF sense of the word).