Light Reading
Why the metro network may become the sweet spot for cable operators to leverage SDN.

Going All IP

John Holobinko
3/24/2014
100%
0%

As networks evolve towards all IP, the ability to commoditize most network functions becomes economically appealing. To understand why the SDN may provide the greatest benefits at the metro network level requires an examination of the network bandwidth and economic challenges in the network core, metro, and access.

"Over-the-top" (OTT) video viewership is rapidly growing and putting great demands on existing network capacity. According to The Ethernet Alliance , network bandwidth is growing at a 59% rate annually. If the future IP network is to deliver virtually all video services, it must be capable of personalizing the video content.

Cable operators have two choices: install customer devices that mimic the functions of the Internet by performing such functions as caching and personalization in the home, or provide these as network functions. Network devices on customer premises will always be challenged by the inability to capitalize on ongoing economic improvements and difficulties in supporting evolving consumer devices, plus cost and deployment times. Velocity -- defined as how fast a provider can react to changing customer behaviors and economics -- will almost always be greater when more functionality is in the network rather than the customer premises.

A major goal of SDN is to both simplify and consolidate network functions, replacing specialized hardware with commodity switches, servers, etc. It enables vertical integration with application control over the network through SDN APIs. Utilizing SDN has the potential to improve service provider velocity and deliver better network economics. But where to implement SDN: the core; the metro edge; the access network?

Today's OTT viewing represents just a very small fraction of total overall consumer video viewing. If all broadcast and unicast video services must traverse the core, then it becomes a major bottleneck, and core capacity would need to expand by two orders or more. Core equipment is expensive, is highly risky to update, and has limited vendors whose equipment primarily uses specialized hardware rather than merchant chips. Thus, it doesn't make economic sense to use the core to deliver the personalized (unicast) services capability required in an all IP network, and therefore it is not the first candidate for SDN.

Access networks must deliver all services to/from residential and business customers. As video traffic explodes, access networks will need to accommodate all of this growth. Twisted pair, coaxial, and multiple fiber technologies are found in the access network, each with its own phy layer and connectivity requirements. Within fiber, there are multiple options such as EPON, GPON, switched Ethernet, and RFoG, for delivering residential and/or business services. It doesn't make sense to create SDN functions that are specialized for each access technology.

Between the core and access networks sits the metro network. 10G Ethernet transport and10G Ethernet switching are becoming cheaper by the minute. A wise sage said, "Never bet against Ethernet". Ethernet switches are simple and easy to make reliable even in outside plant installation, enabling low-cost extension of the metro network. Extending the metro using low-cost Ethernet transport and switching allows the access network to be much dumber and shorter, potentially driving down the cost of adding access capacity.

In this model, the metro becomes the place where the backbone terminates, provides local processing, and then, using switched Ethernet, connects over distances of tens of kilometers to the last few hundred meters of each specialized access network. It becomes logical to put the functions for IP services personalization at the metro network edge. Therefore, the metro network becomes the logical location for SDN functions.

Most network services can be software-defined utilizing commodity servers and switches. By using SDN in the extended metro, existing access networks can potentially become highly agnostic, with service functions instantiated to subscribers via SDN. Everything from DVR-like functionality to MEF-based services can be provided from the metro network.

There will likely be some service functions that require specialized hardware for many years. Examples include deep-packet classification and traffic-shaping functions (such as those that make up part of the cable network's DOCSIS specification), certain forms of encryption, etc. These specialized functions belong at the metro network edge as well.

As services delivery moves to all-IP, all services, whether residential or business, become IP streams, with their primary differences related to bandwidths, tolerable packet losses and latencies. Transport of business services and residential services over a single metro network becomes viable, despite very different QoS requirements. Network expansion costs can be minimized and service velocity maximized.

— John Holobinko, Independent Consultant

(2)  | 
Comment  | 
Print  | 
Newest First  |  Oldest First  |  Threaded View
craigleddy
50%
50%
craigleddy,
User Rank: Blogger
3/25/2014 | 8:21:59 AM
Re: Hitting the nail on the head
Hey John:

Great column. One of the first questions with SDN is defining what the heck it really means. In terms of cable infrastructure, which equipment or functions could be replaced or enhanced by SDN?

The large MSOs are moving toward all-IP delivery and cloud TV. Does SDN require them to change their current game plans or will it become a natural part of their IP migration?      

Hope to see you at LR Cable Next-Gen.

Craig Leddy

 

 
t.bogataj
50%
50%
t.bogataj,
User Rank: Light Sabre
3/24/2014 | 1:04:50 PM
Hitting the nail on the head
Congratulations, John, excellent points. (Not really related to "going all IP" though; more relevant for service delivery, related business models & telco benefits.)

Mostly forgotten about, the metro/aggregation segment is actually an area where the telcos will truly be able to see the benefits of SDN in their broadband (i.e. service-delivery) networks.

I agree that this network segment will require specialized hardware rather than COTS servers and switches; but not because of specific service functions (of which you name a few), but for reliability, avaiability and (most of all!) migration scenarios... which represent another neglected aspect of the SDN hype.

It would be interesting to see other opinions. If none appear, we are both right :)

T.
More Blogs from Column
CSPs armed with real-time operational intelligence are uniquely positioned to realize the true monetary value of the new data economy.
Share your views on the next five years and find out what your peers think too.
The complexity of cloud service sourcing will boost demand for infrastructure-as-a-service.
Automation saves you from repeating the same things over and over again.
Terabit Demonstrator Project to be unveiled at SC14 in New Orleans.
Flash Poll
From The Founder
It's clear to me that the communications industry is divided into two types of people, and only one is living in the real world.
LRTV Huawei Video Resource Center
Building a Secure Telefonica Network With Huawei's High-End Firewall

11|24|14   |   4:37   |   (0) comments


Andrew Davies, IP architect of the Telefonica, a leading digital communications company, discusses the Huawei security gateway solution and putting the solution into the testbed.
LRTV Huawei Video Resource Center
Huawei Partners with Spirent to Verify CE12816's 10GE Port & TRILL Networking Capabilities

11|24|14   |   2:50   |   (0) comments


Spirent Communications is the world's leading supplier for telecom testing appliances and solutions. Spirent has been in a close partnership with Huawei for a long time.
LRTV Huawei Video Resource Center
Saudi Airlines & Its ICT Transformation

11|24|14   |   2:07   |   (0) comments


In this video, Saudi Airlines discusses its network problems and how Huawei's Agile Network is its all-in-one solution.
LRTV Huawei Video Resource Center
Huawei's Agile Switch Benefiting Saudi Arabia's Yamamah Hospital

11|24|14   |   2:40   |   (0) comments


Saudi Arabia's Yamamah Hospital speaks about how Huawei's Agile Switch has improved the medical service's network infrastructure.
LRTV Huawei Video Resource Center
FanPlay & Huawei Build a Wireless Agile Smart Stadium

11|24|14   |   2:13   |   (0) comments


FanPlay is a cloud-based white label service, which is effectively a football fan engagement platform underpinned by mobile payment technology.
LRTV Huawei Video Resource Center
Building an Agile Stadium

11|24|14   |   3:54   |   (0) comments


Stadiums may be thousands of tons of concrete and steel, but they now need to be agile. Being at the stadium may not be as alluring as it once was. Sports franchises and stadium operators discuss how to get fans back.
LRTV Huawei Video Resource Center
Huawei Helps ChinaCache Tackle Challenges in the Internet Industry

11|24|14   |   3:09   |   (0) comments


ChinaCache is China's largest content distribution network supplier. Huawei's CE12800 has provided ChinaCache with very strong support in its establishment of an infrastructure network.
LRTV Huawei Video Resource Center
Cefinity on Managed Security Services & Next-Generation Firewall

11|24|14   |   7:05   |   (0) comments


Cefinity is a cloud management service provider in Southeast Asia. Ivan Zhang, CEO of the company, discusses the implementation of security service management in the cloud era.
LRTV Huawei Video Resource Center
Huawei's Agile Gateway in the Eyes of Cefinity

11|24|14   |   2:11   |   (0) comments


Cefinity is a managed service provider for enterprise networks. The company currently uses Huawei's AR series routers for the most complete range of functions. CEO Ivan Zhang speaks about the advantages of the AR series routers.
LRTV Huawei Video Resource Center
CTO of Bus-Online Talks About Huawei's Agile Gateway

11|24|14   |   2:53   |   (0) comments


Bus-Online covers around 100 million users everyday. In addition to providing mobile TV, and advertising services to the public, Bus-Online has also entered the field of mobile Internet.
LRTV Huawei Video Resource Center
Amsterdam ArenA as an Agile Campus

11|24|14   |   3:31   |   (0) comments


The Amsterdam ArenA, home of the Ajax soccer team, can be a crowded space. ArenA has partnered with Huawei to work on bringing ample bandwidth to 53,000 people at the same time.
LRTV Huawei Video Resource Center
Building a Gigabit Wireless Network

11|24|14   |   3:15   |   (0) comments


3W is dedicated to customer-centric services such as catering, incubator and PR. To do this requires a solid IT structure. In this video, 3W discusses how Huawei has helped to achieve its goals.
Upcoming Live Events
December 2, 2014, New York City
December 3, 2014, New York City
December 8-10, 2014, Reykjavik, Iceland
February 12, 2015, Atlanta, GA
April 14, 2015, New York City, NY
May 6, 2015, McCormick Convention Center, Chicago, IL
May 13-14, 2015, The Westin Peachtree, Atlanta, GA
June 9-10, 2015, Chicago, IL
Infographics
Irish Telecom outlines the rise of VoIP technology, including its adoption within businesses and their perception of its quality.
Hot Topics
Bell Labs Chief Slams 'Toy' Networks
Robert Clark, 11/19/2014
$38.3M: Ain't That a Kik in the SMS
Sarah Reedy, Senior Editor, 11/20/2014
Do You Have a 2020 Vision?
Dennis Mendyk, Vice President of Research, Heavy Reading, 11/21/2014
The New Wave of IP + Optical Integration
Ray Le Maistre, Editor-in-chief, 11/21/2014
Last Chapter (11) for Aereo
Mari Silbey, Independent Technology Editor, 11/21/2014
Like Us on Facebook
Twitter Feed