SDN - Killer Apps

Mon Feb 25 08:23:13 UTC 2013

Hi,

I am trying to understand how SDNs can dramatically change the networking
paradigm and this is my understanding.

Yahoo, Google, etc applications are running on one server and each
application could be theoretically associated with a unique VXLAN tag. This
way service providers will be able to provide QoS per application (by
effectively providing QoS to the VXLAN carried in the pkts). So now Youtube
for example, can get unique QoS treatment from our desktops to the edge of
the network. Form there on core routing will pick up - which remains
largely unaffected by VXLANs.

OpenFlow is useful because it provides a common "CLI/SNMP" with which all
routers from all vendors can be provisioned and monitored. As an example,
VPLS configuration in Juniper, CIsco and AlaLu routers will be very
different. So, provisioning a VPLS service in a network that comprises of
these 3 vendors would require the admins to know the CLIs of all these
routers. If these routers support OpenFlow, then theoretically, one
configuration would work on all routers. OpenFlow would like say "Provision
a LSP" and each router will internally provision an LSP. The admin remains
oblivious to the internal CLIs of these boxes.

The SDN controller is a SW that can again theoretically be made aware of
the entire network. It can look at SNMP traps, etc and can figure out the
exact topology of the network. Based on the SNMP traps, messages it can
determine all failures in the network. It can run routing protocol
simulations and figure out the best topology in the network. This can,
using OpenFlow, be programmed on all routers. So, all heavy CPU processing
task is taken over by the SDN controller. The controller can also take in
requests on what network aware applications require and feed that to the
routers/switches in the network and thus you have an application aware
network provisioned.

I understand that this is just some bit of what we can do with SDN. The
amount of what all can be done is limitless. So, a question to all out
there - Is my understanding of what can be achieved with SDN, is correct?

Glen