The document discusses Open Transport Switch (OTS), a lightweight software switch that enables network virtualization. OTS allows an SDN controller to provision, monitor, and configure underlying transport switches and networks. The document describes two operation modes for OTS - explicit provisioning where the SDN controller provisions every flow on every node, and implicit provisioning where it provisions flows on some nodes. It provides an example demonstration of OTS enabling bandwidth on demand applications over a testbed network.

1. Open Transport Switch
Enable Network Virtualization
Ping Pan, Ph.D.
March 2013

2. NetworkVirtualization is essential for Overlay Services
Overlay Network
Path
Computation
VPN
Bandwidth on
Demand
Packet Infrastructure
Transport Infrastructure Wireless Infrastructure
Offer network services
through overlay
Interface the network
through virtualization

3.  Open Transport Switch (OTS) is a light weight software switch
installed on transport switches for network resource
virtualization
 Through OTS, the SDN Controller can provision, monitor and
configure the underlying switches and networks
The idea behind our thinking…
SDN Controller
WDM/
OTN/
Packet
WDM/
OTN/
Packet
OTS OTS
Traffic Traffic
Applications

4. The high-level design…
OTS-Management
Agent
OTS-Control Agent OTS-Data Agent
Control Plane
XMPP/others JSON/
others
OpenFlow
SDN Controller
Data Forwarding Plane
Physical
Interfaces
N
Internal Communication
Transport
Switch
Platform

5. Operation Mode#1:ExplicitProvisioning
(SDNControlleristoprovisioneveryflowoneverynode!)
Ethernet
Switch
Ethernet /
DWDM
Ethernet
Switch
A B C D
Ethernet /
DWDM
VLAN
100
VLAN
200
VLAN
300
VLAN
400
Wave
X
OTS OTS OTS OTS
SDN
Controller
Topology report:
• L1: 10GE
• L2: to B, 100GE
A D
HE
L2 L4
B C
G
F
L3L1 L5
Provisioning (e.g., OpenFlow):
L2-L3 :: map VLAN-200 packets
to VIF X

6. OperationMode#2:ImplicitProvisioning
(SDNControlleristoprovisioneveryflowonsomenodes!)
LSR
LSR
LSR
LSR POTN
POTN
POTN
POTN ENET
ENET
ENET
ENET
OTS OTS OTS
OTS OTS
OTS
A B C D E F
SDN
Controller
Data Data
Label
Data Data
ODU
Data Data
VLAN
Data
A DB C FE
MPLS OTN (GMPLS)
L2 Ethernet
Provisioning:
• Setup A-B with BW X
Provisioning:
• Setup C-D with BW X
• Map data to C-D
Topology export:
• Node, link and resource (TED)
• Including MPLS for packet,
BGP for IP, GMPLS of optical…

7. ESnet-Infinera SDN Demo
bnl-tb-wdm-3 bnl-tb-wdm-4
40G
100G
20G 20G
20G L1 Tunnel
 SDN Controller communicating with Open Transport Switch (OTS) via OpenFlow
extensions
 Bandwidth on Demand application for Big Data transport
 3 physical transport path options (with varying latencies)
Topology Monitoring App BW on Demand App
ESnet SDN Controller
Mellanox Mellanox
Path #1
Path #2
Path #3
OTS OTS
ESnet LIMAN Production Network
Brookhaven National Laboratory
Testbed

8. Setup an Edge-to-EdgeConnection from Application

9. Provision the Virtual Circuit using OpenFlow

10. Manage Network Resources from Applications

11. Operation Sequence
SDN Controller Transport Node
• Push entire network topology for off-line
path computation
• Push system interface and resource
information for processing
Interface initiation, BW, ERO
In = X, Out = Y, setup cross connect
Run discovery &
routing
Config
Config
Build up FIB
OpenFlowInterface X = Vport X’ etc.
OF
Mirror the FIB
Provision Program HW

12. What we have learned…
Network
Virtualization
Simple to implement over multi-
vendor networks
OpenFlow
Sufficient for circuit provisioning in
multi-layer environment
Network
Operation
Leveraging IP/MPLS protocols in
underlying networks can simplify
overall operation
Opportunities
… are in programming the overlay
directly