nanog mailing list archives

Re: SDN - Killer Apps


From: Jeff Hartley <intensifysecurity () gmail com>
Date: Mon, 25 Feb 2013 10:02:18 -0500

On Mon, Feb 25, 2013 at 3:23 AM, Glen Kent <glen.kent () gmail com> wrote:
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.

Glen


Hi Glen;

You've got a bit of "buzzword bingo" going on in those three
paragraphs...  Perhaps I can steer you in the right direction by
categorizing and pointing you to some search topics.:

VxLAN -- This is in the category of Overlay Networks.  Check out the
draft RFC, and search for terms like "VxLAN tutorial" or "VxLAN
primer".  Think "encapsulation" and "segmentation beyond 4k vlan
tags."   Don't confuse OpenFlow with VxLAN, although there's more than
one use-case where either could theoretically be used.   Note that
VxLAN is just one of a few OLN protocols out there, and none of them
have reached very far beyond the hype curve yet.

OpenFlow vs. OpenStack -- The actual OpenStack project documentation
is a great place to start here.  Orchestration is another category
with several competing efforts, so read as much as possible!

SDN -- Consider this the broad category, but avoid overly broad terms
like "SDN Controller" in favor of "<specific> controller" until you
have the big picture filled in.  For example, "OpenFlow Controller":
There are plenty of docs to read on that specific subject, and there
was a stellar tutorial for first-timers at the start of NANOG57.


...and lastly, the "killer apps": Don't bother researching this until
you've covered the basics above.  There are plenty of vendors and
researchers out there doing the legwork on "killer SDN apps", but
you'll want to understand all the underlying technologies first.


-Jeff


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