In
telecommunication, Software Defined Networking(SDN) is part of 5G future. Most
of Telecom gurus have agreed on a fact that SDN will be next Gen telecom
technology. Now discussion is moving towards Roadmap. How to reach there &
what kind of future it will be, where NFV & SDN will be dominating
in-production technologies in CSP network ?
Following
are 4 key evolution steps for SDN roadmap.. Some companies have already started
towards that direction e.g. AT&T’s Network On Demand offering (http://www.business.att.com/enterprise/Family/network-services/ethernet/#fbid=ZxCUMw9K4KM?hashlink=tab2)
Concept as
SoA (service oriented architecture) has been implemented in CSP’s OSS environment
to integrate various OSS elements in pre-SDN era e.g. Zero touch provisioning. Those were limited to Layer 7 only. OSS &
Network NMS, was two discrete systems, call it IT & Telecom. There was no
integration between system which takes customer order (OSS) and system which
executes customer order(NMS).
SDN movement
has broken the barrier. By creating bridge between high level OSS messages and
low level routing protocol, entire service delivery workflow nearly automated,
as shown figure below. Mind that OSS environment requires fine tuning to be SDN
compatible. TMForum has initiated project ZooM https://www.tmforum.org/zoom/ ). ZOOM is Zero-touch Orchestration, Operations and
Management.
2nd Step:
Service Virtualization
Second step is to decouple data plane and control plane, by virtualization
i.e NFV. Once Software is decoupled from
hardware, it can be hosted on cloud as virtual instance. These will pave way for White box elements as forwarders,
Switches and CPEs. We call it white box elements, because their intelligence is
residing in the cloud, while they act as merely data forwarders. Decoupling
will also commoditize data plane and routing/switching software can be hosted
on any generic X86 COTS hardware.
3rd Step:
Service Centralization
Since routing/switching software is separated, Virtual control
plane can be centralized. Now SDN controller
can control data plane forwarding, by using protocol as Openflow. Centralization
of routing intelligence will unlock many possibilities as WAN optimization, on-fly
routing decisions, scaling bandwidth between
nodes e.g proactive bandwidth Calendaring etc. Currently bandwidth scaling
between two CSP peers are time & resource consuming because of their
multivendor environment & autonomous systems. With centralized SDN controller, bandwidth calendaring
will be much easier. One can integrate
Big Data based analytics Apps at northbound interface of SDN, to analyze the
traffic pattern for optimizing the
transport network like never before.
4th Step:
Service Decomposition
Virtualization will decouple hardware from software, and
decomposition will further modularize software to remove duplicate functions in
service workflow. The intent is to reduce packet capsulation and de-capsulation
in packet forwarding path.
Decomposition at Data plane..
Hardware limitations constraint SDN's configurability. To
deal with this, Telco industry is working on Programmable Data plane. We need
faster software and programmable hardware. Princeton university is working with
concept, called NetASM (http://www.cs.princeton.edu/~mshahbaz/sites/netasm/)
to provide necessary hardware abstraction layer, where underlying hardware
capabilities are completely abstracted
from SDN controller/services above. Hardware abstraction layer will enable
domain specific language as P4 (https://en.wikipedia.org/wiki/P4_(programming_language)
to program underlying hardware.
Decomposition, along with programmable hardware, will change
entire Telco network landscape. Packets will traverse less ports & services
can hop from one to another cloud, without any sort of code change. With more flexibility,
complexity will increase too & those complexities will lead telecom world
to newer technological frontiers.
Thanks for attention..
