1. Why OpenFlow/SDN Can Succeed Where GMPLS Failed
Saurav Das , Guru Parulkar ,
Nick McKeown

2. MPLS a mechanism for forwarding packets for any network protocol.
development:
originally developed in the late 1990s to provide faster packet forwarding for IP routers
the de-facto standard for many carrier and service provider networks
deployment scenarios continue to grow

3. MPLS
illustration:

4. GMPLS conceptually similar to MPLS difference from MPLS:
some physical property of the received data stream is used to deduce which LSP it belongs to
the most commonly used schemes
Timeslot
-on a Time Division Multiplexed (TDM) link
Wavelength
-on a Wavelength Division Multiplexed (WDM) link
fiber or port

5. SDN based Unified Control Architecture

6. The common-map abstraction:
provides full visibility into both packet and circuit switched networks
abstracting away the complexity of state-dissemination from applications
The common-flow abstraction :
flow-tables that take the form of lookup-tables in packet switches and cross-connect tables in circuit switches.

7. GMPLS vs SDN Shortcomings of GMPLS and Advantages of the SDN
Control plane complexity
Lack of the common map-abstraction
Lack of a gradual adoption path

8. Control plane complexity
GMPLS:
The amount of extensions that have gone into the protocols
RSVP:
IntServ + MPLS-TE + GMPLS +UNI interface
SDN:
Use switch-API,network-OS replace :
protocols like OSPF, RSVP
interface like the uni
vendor proprietary islands and interface

9. Lack of the common map-abstraction
As a result
a) services available to IP network are limited to the exact service-level definitions defined
b) the distributed implementation of network-functions across packets and circuits require lots of glue-code, and patchwork to existing protocol.

10. Lack of a gradual adoption path

11. Reference www.openflow.org/wk/images/4/40/Abstract.pdf‎
SDN Based Unified Control Architecture Saurav Das, Guru Parulkar and Nick McKeown