This document summarizes Richard Clegg's talk on pushing OpenFlow switches to access networks like Gigabit Ethernet Passive Optical Networks (GEPON). It discusses the ALIEN project, which aims to expand OpenFlow functionality to new platforms like access networks and optical devices. Specifically for GEPON, the document proposes surrounding the non-OpenFlow OLT with OpenFlow-enabled switches to abstract the whole system as a single distributed OpenFlow switch and control it from a controller. It also briefly mentions Clegg's other work on non-orthogonal FDM for spectral efficiency and using OpenFlow for network resilience.

1. OpenFlow in the access –
pushing OpenFlow switches to
the last mile
Richard G. Clegg (richard@richardclegg.org)
University College London, Department of Electronic Engineering
Talk to Brazil/UK conference 2014
(Prepared using LATEX and beamer.)

2. University College London – Electronic Engineering
Communcations and Information Systems Group – 6
academics, 20 researchers, 10 PhD students.
Optical Networks Group and Photonics Group – both similar
size.

3. The ALIEN project
ALIEN – Expanding the availability of OpenFlow
Get OpenFlow working on new types of devices. Expand use of
OpenFlow by making it useful for new platforms.
Programmable platforms – NetFPGA and similar.
Access networks – e.g. GEPON and DOCSIS.
Optical devices – require OpenFlow extensions.

4. The GEPON (Gigabit Ethernet Passive Optical Network)
ONU ONU ONU
End User machines
Switch
OLT
Splitter
ONU

5. Getting OpenFlow on GEPON
Want to make whole system of switch, OLT, splitter ONU
present as single massively distributed OF switch.
Problem with making GEPON OpenFlow capable:
Proprietary device, no knowledge of chips or drivers.
Not intended as programmable.
ONU cheap low power consumer unit.
Solution:
Make use of fact that OLT usually needs switch before it
anyway.
Give OLT Open Flow capable front end switch (xdpd on
NetFPGA).
OLT can switch to ONU on VLANs.
Use a mapping to VLANs in lower level open flow switch.
Controller sees only higher level abstract switch.

6. The GEPON with OpenFlow
ONU
ONU
ONU
ONU
OLT xDPD
MGMT
GEPON
OFC
VLAN
tags
Internet
OpenFlow enabled GEPON
LLID
tags
xcpd
control
path
daemon
OF
OF
Note – approach is generic – could work for many access
devices.
Another partner is working on the generic approach of
surrounding the non OF device with OF switches.

7. My oxther work on optical networks and SDN
Non Orthogonal (Spectrally Efficient) FDM
Traditional OFDM fixed relationship between symbol period and
frequency separation. “Squeezing” results in interference but can
recover the signal. Spectral efficiency increased up to 20% –
software test done, hardware tests underway.
A practical system for improved efficiency in FDM RG Clegg, S
Isam, I Kannaras, I Darwazeh, IET Communications 2013.
SDN for network resilience
Often multiple routes from data centre to destination on Internet.
OpenFlow used to tag packets at machine ingress. Tags used to
route packets at datacentre egress. Quick failover in case of path
failure.
Software-defined network support for transport resilience JT
Araujo, R Landa, RG. Clegg, G Pavlou, IEEE/IFIP NOMS 2014

8. Conclusions – Optical work at UCL
ALIEN project
In ALIEN we are working to get OpenFlow working on optical
access networks. We are also testing CCN (ccnx) over the OFELIA
testbed over a number of OpenFlow switches. Large-scale
OpenFlow experimenation.
Other work at UCL
There is a large amount of other optical work at UCL, optical
network testbeds, high end passive optical networking.