Light Reading

Learning From Mistakes

Jeff Finkelstein
1/20/2014
100%
0%

    If you're not failing every now and again, it's a sign you're not doing anything very innovative. – Woody Allen

Or, as I like to look at it, you never learn anything by getting it right. Most great lessons are learned when you are digging yourself out of a hole. A friend is someone who throws you a rope to get out, but a best friend is the person in the hole with you.

Many years ago I worked on a project involving a software system called the Distributed Computing Environment (DCE), which came out of another project I worked on called Project Athena (but that is a story for another blog). DCE was a toolkit for developing client-server applications using remote procedure calls (RPC), location services, time synchronization, authentication services, and a distributed file system (DFS).

While DCE did not gain much acceptance in its initial incarnation, we did learn a lot about how to decompose programs into functional components and have servers in the network run those specific functions. By using the location services, we were able to have servers execute specific sub-programs or functions, based on a variety of selection options (e.g. proximity, spare compute cycles, or other criteria.) DCE was developed in response to dissatisfaction with mainframes and super-minis being costly, hard to manage, and difficult to scale in hardware, as well as power and cooling issues and rackspace requirements.

We find ourselves at a similar, though not quite identical, place in today's cable architecture. We may continue to increase the density of edge devices, just as we did in early 1990s, but is that really the right path to take? We can easily ride the curves of Moore, Koomey, and Denard for some time to increase the density of access equipment. However, as we learned in the days of the mainframe and super-minis, if we fail to learn from our mistakes to prepare adequately for future changes, we are highly likely to make the same poor choices again.

As part of the thought exercise, let's consider our current edge devices, including cable modem termination systems (CMTSs) and optical line terminals (OLTs). Today's DOCSIS edge devices perform many functions, primarily L2 (switching) and L3 (routing). Some functions are what traditionally would be part of an edge router, others are more like an aggregation switch, and many are similar to a media converter.

As each set of actions is scaled, the size, power, and complexities of the edge device will require either more dense and capable silicon or a larger form factor. An OLT traditionally is a L2 device with the L3 functions handled in a broadband remote access server (BRAS). But, with Converged Cable Access Platform (CCAP), we are considering a hybrid that manages both layers in a single device, like a CMTS does today.

So how do we begin thinking about separating the different layers? Which tools are available? What do the layers look like? And, more importantly, why would we do it?

This is where software-defined networking (SDN) and network functions virtualization (NFV) enter the discussion. To get things started, let's begin with a diagram of the higher-level functions performed within a DOCSIS edge device (e.g. a CMTS or CCAP).

Thanks to Harmonic Inc. for allowing me to use this diagram:

Source: Harmonic Inc.
Source: Harmonic Inc.

As you look at this image, you can see the top-level functions that a DOCSIS edge access device performs. As we begin to consider ways to use SDN and NFV, this functional breakdown will be our starting point for decomposing functions.

In my next blog, I will start discussing possible ways to break down the functions into layers and begin to think about separating those layers into a distributed access architecture.

Until then...

— Jeff Finkelstein, Executive Director of Strategic Architecture, Cox Communications

(4)  | 
Comment  | 
Print  | 
Newest First  |  Oldest First  |  Threaded View        ADD A COMMENT
jlfinkels
50%
50%
jlfinkels,
User Rank: Light Beer
1/21/2014 | 5:32:16 PM
Re: Performance?
To me both SDN and NFV are not about performance, they are about scalability. I would not expect us to compare them at that level.

Reliability is a great question. In our networks today we have many components where we build in redundancy. They tend to be higher in the network where they aggregate a significant number of customers or if lower in the network it is usually power components that tend to fail or line cards so we can perform in-service upgrades without impacting customers.

Once we reduce a serving group size to 125 or so HHP, how much redundancy do we need? I would say this needs study and analysis by those that track reliability to a component and eco-system level. I am very interested in hearing what these engineers have to say about it.
jlfinkels
50%
50%
jlfinkels,
User Rank: Light Beer
1/21/2014 | 5:26:51 PM
Re: Which functions first?
Ray, I agree that there will be similarities, but there is also a basic difference in how we both approach the network. The access devices in the telco domain tend to have much fewer customers than in the cable space. As a result separating out L2 from L3 is in some ways simpler. In cable with more functionality at the edge we have an inherently more complex box which makes separating functions more difficult.

If I was going to make a guess, I would think that the functions that are already defined in standards (PCE - Path Computation Element for one) would be the first we will see. As new hardware is developed over time there is an opportunity to rethink how we build our cable access networks. The amount of compute cycles needed remains, but where we place it is an important choice to make.

-k

 
sam masud
50%
50%
sam masud,
User Rank: Light Sabre
1/21/2014 | 10:13:33 AM
Performance?
Jeff,

 

Along the lines of Ray's question, I'm curious whether you have any concerns at this point about the performance and/or reliability of NFV?
Ray@LR
50%
50%
Ray@LR,
User Rank: Blogger
1/20/2014 | 2:09:00 PM
Which functions first?
Jeff

Which function(s) do you think will be subject to the NFV treatment first in cable networks?

Curious to see how it relates to the similar debate in telco networks.

Ray
More Blogs from Column
Can network appliances be virtualized and still provide high performance at high speeds?
It's possible as infrastructure convergence facilitates further services convergence.
Dan Pitt of the Open Networking Foundation (ONF) lays down a challenge to OpenFlow's naysayers.
Telecom carriers need to build, buy or partner for many of the technology enhancements they put into the networks or customer solutions each year.
The future of communications depends on technology licensing, according to Ericsson's Monica Magnusson.
From The Founder
Against the odds, Huawei is growing its telecoms networking equipment business in the US -- that should be ringing some alarm bells for domestic vendors.
Flash Poll
Live Streaming Video
CLOUD / MANAGED SERVICES: Prepping Ethernet for the Cloud
Moderator: Ray LeMaistre Panelists: Jeremy Bye, Leonard Sheahan
Between the CEOs
Metaswitch's New CEO Martin Lund Discusses His Role

9|2|15   |   11:27   |   (1) comment


Technology industry veteran Martin Lund joins Metaswitch Networks this week as the company's new CEO. In this interview, Lund discusses his new role and the industry's progress with Light Reading CEO Steve Saunders. Lund believes that the industry disruption caused by SDN and NFV is creating opportunities for companies like Metaswitch – network software providers ...
Telecom Innovators Video Showcase
Nominum on Leveraging the Power of DNS to Deliver Superior Subscriber Experiences

9|2|15   |   07:13   |   (0) comments


Nominum CEO Gary Messiana talks about the challenges service providers face in competing for a much more sophisticated customer, a customer that has heightened expectations for more personalized and compelling digital experiences. Providers are focusing their efforts on delivering higher value subscriber services, retaining their existing customers and increasing ...
Between the CEOs
CEO Chat With Jeff Miller, ActiveVideo

8|28|15   |   19:05   |   (0) comments


Jeff Miller, President and CEO of ActiveVideo, talks to Light Reading founder and CEO Steve Saunders about the impact of virtualization on the TV and video distribution market.
LRTV Huawei Video Resource Center
Vodafone: Mobile Money Is About Customer Trust

8|27|15   |   06.36   |   (0) comments


Light Reading spoke with Vodafone's Ian Ravenscroft about the unique responsibilities and opportunities facing operators handling customers' financial transactions over the network.
Telecom Innovators Video Showcase
Palo Alto Networks on Expanding in the Carrier/Service Provider Market

8|26|15   |   07:54   |   (0) comments


Alfred Lee from Palo Alto Networks tells Steve Saunders about their new chassis-based system, the PA-7080, and how it can benefit service providers compared to legacy firewalls.
LRTV Custom TV
Global Services Forum Preview

8|25|15   |   02:36   |   (0) comments


Light Reading's CEO and Founder Steve Saunders talks about Huawei's upcoming Global Services Forum with the help of Heavy Reading's Patrick Donegan and Teresa Mastrangelo.
Telecom Innovators Video Showcase
Infoblox on DNS Threat Index

8|19|15   |   04:39   |   (0) comments


Dilip Pillaipakam from Infoblox talks to Steve Saunders about his company's core network services.
Between the CEOs
CEO Chat With Ihab Tarazi, Equinix

8|14|15   |   20:18   |   (1) comment


Equinix CTO Ihab Tarazi talks to Light Reading founder and CEO Steve Saunders about the dramatic changes in the data center, cloud and interconnect markets and discusses the impact of SDN and NFV in the coming years.
Telecom Innovators Video Showcase
The Netformx Ecosystem

8|14|15   |   09:39   |   (1) comment


Ittai Bareket, CEO of Netformx, talks with Steve Saunders about the Netformx Ecosystem, which employs cutting-edge prescriptive analytics to help solution providers maximize profits.
Telecom Innovators Video Showcase
Versa Networks on Leveraging VNFs

8|12|15   |   07:37   |   (0) comments


Kumar Mehta, founder and CEO of stealth mode startup Versa Networks, talks with Steve Saunders about how providers can best leverage virtualized network functions (VNFs).
LRTV Custom TV
Transforming the Network Through OPNFV

8|5|15   |   7:09   |   (0) comments


Sandra Rivera, VP Data Center Group; GM Network Platforms Group, Intel Corporation, on OPNFV Arno and how the industry is coming together to accelerate the deployment of NFV and transform the network.
LRTV Huawei Video Resource Center
Huawei ONS Product Demo

8|3|15   |   6:01   |   (0) comments


Huawei shows at Open Networking Summit 2015 in Santa Clara how its SDN and NFV solutions embrace openness.
Upcoming Live Events
September 16-17, 2015, The Westin Galleria Dallas, Dallas, TX
September 16, 2015, The Westin Galleria Dallas, Dallas, TX
September 16, 2015, The Westin Galleria Dallas, Dallas, TX
September 29-30, 2015, The Westin Grand Müchen, Munich, Germany
October 14-15, 2015, New Orleans Ernest N. Morial Convention Center, New Orleans, LA
November 5, 2015, Hilton Santa Clara, Santa Clara, CA
November 17, 2015, Santa Clara, California
December 1, 2015, The Westin Times Square, New York City
December 2, 2015, The Westin Times Square, New York City
All Upcoming Live Events
Infographics
Cisco's cloud and virtualization portfolio can increase business agility and innovation by building a more flexible network architecture.
Hot Topics
T-Mobile CEO Plays Data Traffic Cop
Sarah Thomas, Editorial Operations Director, 8/31/2015
CEO Chat With Bill Gates
Steve Saunders, CEO and founder, Light Reading, 8/31/2015
Time to Monetize Cable WiFi
Alan Breznick, Cable/Video Practice Leader, 8/31/2015
New Apple TV: More $$, Not Content – Report
Mari Silbey, Senior Editor, Cable/Video, 8/31/2015
Ex-AlcaLu Boss Tasked With Bolstering Altice
Iain Morris, News Editor, 9/1/2015
Like Us on Facebook
Twitter Feed
September 16, 2015
Wi-Fi First or Second?
September 22, 2015
Media Begins With “Me”
Webinar Archive
BETWEEN THE CEOs - Executive Interviews
Technology industry veteran Martin Lund joins Metaswitch Networks this week as the company's new CEO. In this interview, Lund discusses his new role and the industry's progress with Light Reading CEO Steve Saunders. Lund believes that the industry disruption caused by SDN and NFV is creating opportunities for companies like Metaswitch – network software providers with the agility to embrace new technologies quickly and the ability to deliver on substantial projects for global network operators.
The scene: Last Saturday, lunchtime, the interior of a shi-shi-foo-foo eatery in Manhattan's SoHo district.
Cats with Phones
Tastes Like Fish Click Here
Please hold while I lick the phone.