& cplSiteName &

It's Time to Focus on One-Way Network Delays

Alan Breznick
5/15/2017
50%
50%

In a world where most video traffic only flows downstream, it's high time for wireline and wireless service providers to reconsider how they tackle the critical problem of excessive network delays.

Why? Because high latency, or lengthy network delays, is an issue bedeviling video content and service providers of all stripes and sizes. Buffering delays of even just a few milliseconds can lead to a poorer customer quality-of-experience (QoE) and much higher rates of video abandonment by subscribers, according to research conducted by Akamai Technologies Inc. (Nasdaq: AKAM) and others. In turn, these higher rates of abandonment can lead to substantial amounts of lost revenue.

How substantial? Well, Amazon.com Inc. (Nasdaq: AMZN) figures that a page load slowdown of a just a single second could cost it $1.6 billion in sales each year. Google (Nasdaq: GOOG) has calculated that slowing its search results by merely four-tenths of a second could wipe out 8 million searches per day, costing it countless millions in ad revenues. And a research paper published last year concluded that a millisecond delay at a data center could cause $100 million in lost revenues.

Such latency issues will only become more paramount as video increasingly rules both the world and the Internet. In the latest edition of its Visual Networking Index (VNI), Cisco Systems Inc. (Nasdaq: CSCO) projects that IP video will account for a whopping 82% of all global IP traffic by 2020, up from 70% in 2015. Similarly, the Cisco VNI forecast predicts that consumer Internet video will make up 82% of all consumer Internet traffic by the decade's end, up from 68% in 2015. Plus, the VNI report projects that mobile video will account for 78% of the world's mobile data traffic by 2021, up from 60% last year.

With more and more video traffic pulsing over their lines, service providers know they need to find ways to target latency issues and cut down on network delays or risk losing customers in droves. But what they may not know, and need to know, is that viewer QoE will likely become more and more of a crucial differentiator when consumers are choosing between video providers in the future, as the research is beginning to indicate.

Many service providers are trying to address the latency issue by measuring and monitoring video traffic delays in both directions on their networks, using such legacy methods as packet timing and Global Positioning System (GPS). They then take the two-way latency results and simply divide them in two to calculate the estimated delay in each direction. But this approach is faulty and can lead to big problems for network operators.

The obvious shortcoming with these rough estimates is that they don't offer any visibility into what might actually be happening on either network path. As a result, the estimates for one-way delays could be way off because of the asymmetrical nature of most video traffic. Worse yet, these estimates could wind up producing "false positives," incorrectly indicating no latency problems overall when in fact there may be huge traffic delays occurring in one direction or the other.

It seems clear, then, that service providers must measure and monitor one-way network latency directly and accurately. Unfortunately, though, the traditional methods to track one-way delays accurately are complex and expensive.

Take GPS, for instance. While this type of approach usually delivers the most accurate delay measurements, it's quite costly because it requires investment at all measurement sites. It can also be challenging to carry out in urban settings due to intermittent signals, as well as in indoor settings where GPS deployment is tricky. Plus, there's the extra opex cost of rolling a truck to repair or replace faulty equipment.

So, a better type of one-way latency testing is sorely needed. Without a better approach, video providers will not be able to do much better than guess about the scale of the latency issues they are struggling to master. Consider this question: How much is your inability to measure one-way latency costing your company?

This blog is sponsored by EXFO.

— Alan Breznick, Cable/Video Practice Leader, Light Reading

(6)  | 
Comment  | 
Print  | 
Newest First  |  Oldest First  |  Threaded View        ADD A COMMENT
cahitakin19
50%
50%
cahitakin19,
User Rank: Light Beer
5/22/2017 | 2:38:22 PM
One-way network delay also matters a lot in SD-WAN
Interesting article and great conversation in comments. Being in the SD-WAN (also known as broadband bonding) industry, I just wanted to add that one-way delay (as well as jitter), as opposed RTT (Rount Trip Time) is essential for SD-WAN technologies as well since the real-time per packet decisions are made for steering traffic on one of the multitude of WAN connections in real-time. One-way delay is not the only metric, however, is a critical one. In SD-WAN setups, where the vendor has control over the two-ends of the over-the-top tunnel and therefore can utilize their technology, telemetry and more specifically accuracy in one way delay measurements become a little easier.
Sr.Embed22197
50%
50%
Sr.Embed22197,
User Rank: Light Beer
5/15/2017 | 2:18:37 PM
Re: Ummm
It's actually a bit of both, yes.

I guess my original point is that One Way measurments have some clock sync requirements that are far more strict than Two Way.  Y.1731 DMM, TWAMP, the test can compensate to a certain degree because you can factor out the time differences at each end.  One Way testing, the clocks have to be sync'd a lot tighter.

It's a price upgrade for hardware and infrastructure to do that and customers hate spending the extra money.  Most switches currently installed that I have to support, still rely on NTP.

The point of the article is that One Way testing is needed, and I'm seeing requests to add it, as well as defects reports about it's accuracy on older devices.  I agree that it's useful, but making it report valid numbers isn't just a slight tweak of the software. :)
brooks7
50%
50%
brooks7,
User Rank: Light Sabre
5/15/2017 | 1:33:46 PM
Ummm
I think about 1/2 your commentary is actually about Jitter and not latency.  Absolute Latency is important at the start of a stream (which includes channel switching).  But once a stream has started it is packet jitter that is the problem (i.e. the variance in delay between receipt of packets).

seven

 
Sr.Embed22197
50%
50%
Sr.Embed22197,
User Rank: Light Beer
5/15/2017 | 12:50:48 PM
Re: When the devices clocks are accurate enough ...
I'm working with 100G Ethernet. :)  PtP is the protocol they should be using, to have a chance of being accurate, so I agree with you there.  It's not available on low end switches though and customers want cheap switches.

Over multiple hops, from the customers testing center to the NTE, the end to end clocks have be be in sync if you're going to use something like Y.1731 1DM.  Sure, there are games you can play, run 100 frame tests, throw out the outliers, take the average.  You're still going to get odd results at times because someplace in the middle of the test, NTP updated the clock and slewed it someplace.

Customers hate running repeating tests and noticing occasional results that wandered out into the weeds because of a clock update.  Everytime a leap second hits, we get a couple of calls and we explain it all over again.
Duh!
50%
50%
Duh!,
User Rank: Light Sabre
5/15/2017 | 12:29:14 PM
Re: When the devices clocks are accurate enough ...
Off by a couple of orders of magnitude. Prop delay through fiber is 4.9 microseconds (μs) per kilometer. Serialization delay at 1 Gbps for an MTU-sized packet is 12.3 μs.

IEEE 1588 - Precision Time Protocol can provide commensurate accuracy.
Sr.Embed22197
50%
50%
Sr.Embed22197,
User Rank: Light Beer
5/15/2017 | 12:07:11 PM
When the devices clocks are accurate enough ...
When most vendors/customers use NTP to keep their clock accurate, I'd love to hear somebody explain how a clock that is +/- 128ms accuracy is going to get used to time the one way flight of a packet that takes nanoseconds to travel.

Yeah, there are better time protocols and sync Ethernet, but nobody wants to pay for it.

 
More Blogs from Heavy Lifting Analyst Notes
To fully benefit from the opportunities of 5G, IoT and NFV, operators must assure their infrastructure, services and processes throughout each stage of their virtualization, automation and DevOps journey.
With the current industry consensus for deployment to commence broadly in 2020, now is the time to prepare transport networks for the coming of 5G.
The 2017 GCI ratings, which are used to compare digital transformation activity in different countries, hold some surprising results.
Healthcare could be a goldmine for mobile operators, but they will need to do it right.
From The Founder
The time has come for a telecom app store to save the industry.
Flash Poll
Live Streaming Video
Charting the CSP's Future
Six different communications service providers join to debate their visions of the future CSP, following a landmark presentation from AT&T on its massive virtualization efforts and a look back on where the telecom industry has been and where it's going from two industry veterans.
LRTV Documentaries
Service Provider Panel: Partnering in the Digital Era

5|22|17   |     |   (0) comments


Coopetition has always been part of telecom, but the ecosphere now includes data centers, vendors, apps developers, cloud service providers and Internet content providers. This BCE 2017 panel explores the new attitudes among network operators as to the value and variety of ...
LRTV Interviews
Site Demo: AT&T's IoT Flow Platform

5|19|17   |   04:25   |   (0) comments


At AT&T's R&D center in Tel Aviv, Israel, project leader Eyal Segev talks about the operator's Flow platform and how it helps to prototype IoT applications.
LRTV Documentaries
Agent of Change: A Q&A With AT&T's John Donovan

5|18|17   |     |   (0) comments


Carol Wilson talks with the man leading AT&T's transformation efforts about the challenge of change.
LRTV Documentaries
BCE Service Provider Panel: The New Business Realities

5|18|17   |     |   (0) comments


For virtualization to happen, the telecom industry first has to grapple with key functional aspects of SDN and NFV that need to be universal, such as onboarding of virtualized network functions and federation of software-defined networks.
LRTV Interviews
BCE Service Provider Keynote: CenturyLink

5|16|17   |   22:32   |   (0) comments


Aamir Hussain leads the Product Development and Technology organization at CenturyLink, which includes the company's information technology function. He is an experienced senior technology executive with more than 25 years of proven success in the implementation of global technology operations, operationalization of complex technology, infrastructures and business ...
LRTV Interviews
CenturyLink CTO on Transformation

5|16|17   |   7:43   |   (0) comments


The 50-year-old telco has already gone through several transformations, including every time it made an acquisition, but its purchase of Level 3 coupled with changes in technology and customer expectations necessitates its biggest transformation yet.
LRTV Documentaries
Light Reading Hall of Fame 2017

5|15|17   |   5:05   |   (1) comment


Find out who made it into Light Reading's Hall of Fame this year.
LRTV Interviews
Site Visit: AT&T's Tel Aviv R&D Center

5|15|17   |   09:58   |   (1) comment


Nir Shalom, general manager and VP of application development at AT&T Israel, talks about the key service developments undertaken at the AT&T R&D facility in Tel Aviv and how the team there has adopted new ways of working.
Telecom Innovators Video Showcase
Act on Your Intelligence With Amdocs aia!

5|15|17   |     |   (0) comments


Amdocs CMO Gary Miles explains how communications service providers can seize the AI opportunity with Amdocs real-time digital intelligence platform.
LRTV Interviews
Logtel CEO: Making Sense of IoT

5|15|17   |   09:48   |   (0) comments


Jacques Bensimon, founder and CEO of Tel Aviv-based training and consultancy Logtel, talks about the need to make IoT more than just a buzzword.
LRTV Huawei Video Resource Center
The Challenges of Mobile Banking Implementation

5|12|17   |     |   (0) comments


Kamal Quadir of bKash Limited explains the challenges and needs of implementing mobile banking in the Bangladesh market.
LRTV Interviews
Tel Aviv: A Hub of Innovation

5|10|17   |   07:58   |   (0) comments


Light Reading's Ray Le Maistre and Dan Allen discuss the technology innovation, food and amazing sights they witnessed during a recent trip to Israel.
Infographics
With the mobile ecosystem becoming increasingly vulnerable to security threats, AdaptiveMobile has laid out some of the key considerations for the wireless community.
Hot Topics
BSS Is BS, Says KPN Tech Boss
Iain Morris, News Editor, 5/16/2017
AT&T's Donovan: Women Adapt Faster Than Men
Sarah Thomas, Director, Women in Comms, 5/18/2017
Verizon on M&A: Who Needs a Cableco?
Mari Silbey, Senior Editor, Cable/Video, 5/17/2017
Standardization Needs Room for Innovation
Mitch Wagner, Editor, Enterprise Cloud, 5/17/2017
Fright Wigs & Cocktails: BCE 2017 in Pics
Mitch Wagner, Editor, Enterprise Cloud, 5/19/2017
Like Us on Facebook
Twitter Feed
BETWEEN THE CEOs - Executive Interviews
One of the nice bits of my job (other than the teeny tiny salary, obviously) is that I get to pick and choose who I interview for this slot on the Light Reading home ...
TEOCO Founder and CEO Atul Jain talks to Light Reading Founder and CEO Steve Saunders about the challenges around cost control and service monetization in the mobile and IoT sectors.
Animals with Phones
What Brogrammers Look Like to the Rest of Us Click Here
Live Digital Audio

Playing it safe can only get you so far. Sometimes the biggest bets have the biggest payouts, and that is true in your career as well. For this radio show, Caroline Chan, general manager of the 5G Infrastructure Division of the Network Platform Group at Intel, will share her own personal story of how she successfully took big bets to build a successful career, as well as offer advice on how you can do the same. We’ll cover everything from how to overcome fear and manage risk, how to be prepared for where technology is going in the future and how to structure your career in a way to ensure you keep progressing. Chan, a seasoned telecom veteran and effective risk taker herself, will also leave plenty of time to answer all your questions live on the air.