Thursday, August 6, 2015

4 key steps of SDN Roadmap for CSP


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)   

 1st Step: Service Provisioning

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..

 
 

 



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