Monthly Archives: November 2014

Riding the SD-WAN Wave

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Software Defined Networking has changed the way that organizations think about their network infrastructure.  Companies are looking at increasing automation of mundane tasks, orchestration of policy, and even using white box switches with the help of new unbound operating systems.  A new class of technologies that is coming to market hopes to reduce complexity and cost for the Achilles Heel of many enterprises: the Wide Area Network (WAN).

Do You WANt To Build A Snowman?

The WAN has always been a sore spot for enterprise networks.  It’s necessary to connect your organization to the world.  If you have remote sites or branch locations, it is critical for daily operations.  If you have an e-commerce footprint your WAN connection needs to be able to handle the generated traffic.  But good WAN connectivity costs money.  Lots of money.

WAN protocols are constantly being refined to come up with the fastest possible transmission and the highest possible uptime.  Frame Relay, Asynchronous Transfer Mode (ATM) and Multi-Protocol Label Switching (MPLS) are a succession of technologies that have shaped enterprise WAN connectivity for over a decade.  They have their strengths and weaknesses.  But it is difficult to build an enterprise WAN without one.

Some customers can’t get MPLS connectivity.  Or even Frame Relay for the matter.  Their locations are too remote or the cost of having the connection installed is far above the return on investment.  These customers are often forced to resort to consumer-class connections, like cable modems, Digital Subscriber Line (DSL), or even 4G/LTE modem uplinks.  While cheaper and easy to install, these solutions are often not as robust as their business-grade counterparts.  And when it comes to support on a down circuit…

Redefining the WAN

How does Software Defined WAN (SD-WAN) help?  SD-WAN technologies from companies like Silver Peak, CloudGenix, and Viptela function like overlay networks for the WAN.  They take the various inputs that you have, such as MPLS, cable, and 4G/LTE networks.  These inputs are then arranged in such a way as to allow you to intelligently program how traffic will behave on the links.  If you want only critical business traffic on the MPLS circuit during business hours you can do that.  If you want to ensure the 4G/LTE uplink is only used in the event of an emergency outage, you can do that too.  You can even program various costs and metrics into the system to help you make decisions about when a given link would be a better economic decision given the time of day or amount of transferred data.

You’re probably saying to yourself, “But I can do all of that today.” And you would be right. But all of this has to happen manually, or at the least require a lot of programming.  If you’ve ever tried to configure OER/PFR on a Cisco router you know what I’m talking about.  And that’s just one vendor’s equipment.  What if there are multiple devices in play?  How do you configure the edge routers for fifty sites?  What happens when a circuit goes down at 3 a.m.?  Having a simple interface for making decisions or even the ability to script actions based on inputs makes the system much more flexible and responsive.

It all comes down to a simple number for all parties involved.  For engineering, the amount of time spent configuring and maintaining complex WAN connectivity will be reduced.  Engineers love not needing to spend time on things.  For the decision makers (and bean counters), it all comes down to money.  SD-WAN technologies reduce costs by better utilizing existing infrastructure.  Eventually, their analysis can allow you to reduce or remove unnecessary connectivity.  That means more money in the pockets of the people that want the money.

Tom’s Take

I’ve referred to WAN applications as the “hello world” for SDN.  That’s because I saw so many people demoing them when SDN was first being talked about.  Cisco did this at Cisco Live 2012 in San Diego.  SD-WAN didn’t really become a concrete thing in my mind until is was the topic of discussion on the Spring ONUG meeting.  Those are the people with the money.  And they are looking at the cost savings and optimization from SD-WAN technologies.  You can better believe that the first wave of SD-WAN that you’ve seen in the last couple of months is just the precursor to a wider look at connectivity in general.  Better get ready to surf.

Wires Are The Exception

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Last week I went to go talk to a group of vocational students about networking.  While I was there, I needed to send a couple of emails.  I prefer to write emails from my laptop, so I pulled it out of my bag between talks and did the first thing that came to mind: I asked for the wireless SSID and password.  Afterwards, I started thinking about how far we’ve come with connectivity.

I can still remember working with a wireless card back in 2001 trying to get the drivers to play nice with Windows 2000.  Now, wireless cards are the rule and wired ports are the exception.  My primary laptop needs a dongle to have a wired port.  My new Mac Mini is happily churning along halfway across the room connected to my network as a server over wireless.  It would appear that the user edge quietly became wireless and no tears were shed for the wire.

It’s also funny that a lot of the big security features like 802.1x and port security became less and less of an issue once open ports started disappearing in common areas.  802.1x for wired connections is barely even talked about now.  It’s more of an authentication mechanism for wireless now.  I’ve even heard some vendors of these solutions touting the advantages of using it with wireless and then throwing in the afterthought comment, “We also made it easy to configured for wired connections too.”

We still need wires, of course.  Access points have to connect to the infrastructure.  Power still can be delivered via microwave.  But the shift toward wireless has made ubiquitous cabling unnecessary.  I used to propose a minimum of four cable drops per room to provide connectivity in a school.  I would often argue for six in case a teacher wanted to later add an IP phone and a couple of student workstations.  Now, almost everything is wireless.  The single wire powers a desk phone and an antiquated desktop.  Progressive schools are replacing the phones with soft clients and the desktops with teach laptops.

The wire is not in any danger of becoming extinct.  But it is going to be relegated to the special purpose category.  Wires will only live behind the scenes in data centers and IDF closets.  They will be the thing that we throw in our bag for emergencies, like an extra console cable or a VGA adapter.

Wireless is the future.  People don’t walk into a coffee shop and ask, “Hey, where’s the Ethernet cable?” Users don’t crowd around wall plates with hubs to split the one network drop into four or eight so they can plug their tablets in.  Companies like Aruba Networks recognized this already when they started posing questions about all-wireless designs.  We even made a video about it:

While I don’t know that the all-wireless design is going to work, I can say with certainty that the only wires that will be running across your desktop soon will be power cables and the occasional USB cord.  Ethernet will be relegated to the same class as electrical wires connected to breaker boxes and water pipes.  Important and unseen.

The Trap of Net Neutrality

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net-neutrality

The President recently released a video and statement urging the Federal Communications Commission (FCC) to support net neutrality and ensure that there will be no “pay for play” access to websites or punishment for sites that compete against a provider’s interests.  I wholeheartedly support the idea of net neutrality.  However, I do like to stand on my Devil’s Advocate soapbox every once in a while.  Today, I want to show you why a truly neutral Internet may not be in our best interests.

Lawful Neutral

If the FCC mandates a law that the Internet must remain neutral, it will mean that all traffic must be treated equally.  That’s good, right?  It means that a provider can’t slow my Netflix stream or make their own webmail service load faster than Google or Yahoo.  It also means that the provider can’t legally prioritize packets either.

Think about that for a moment.  We, as network and voice engineers, have spent many an hour configuring our networks to be as unfair as possible.  Low-latency queues for voice traffic.  Weighted fair queues for video and critical applications.  Scavenger traffic classes and VLANs for file sharers and other undesirable bulk noise.  These plans take weeks to draw up and even longer to implement properly.  It helps us make sense out of the chaos in the network.

By mandating a truly neutral net, we are saying that those carefully marked packets can’t escape from the local network with their markings intact.  We can’t prioritize voice packets once they escape the edge routers.  And if we move applications to the public cloud, we can’t ensure priority access.  Legally, the providers will be forced to remark all CoS and DSCP values at the edge and wash their hands of the whole thing.

And what about provider MPLS circuits?  If the legally mandated neutral provider is administering your MPLS circuits (as they do in small and medium enterprise), can they copy the DSCP values to the MPLS TE field before forwarding the packet?  Where does the law stand on prioritizing private traffic transiting a semi-public link?

Chaotic Neutral

The idea of net neutrality is that no provider should have the right to decide how your traffic should be handled.  But providers will extend that idea to say they can’t deal with any kind of marking.  They won’t legally be able to offer you differentiated service even if you were wiling to pay for it.  That’s the double-edge sword of neutrality.

You can be sure that the providers will already have found a “solution” to the problem.  Today, quality of service (QoS) only becomes an issue when the link becomes congested.  Packets don’t queue up if there’s bandwidth available to use.  So the provider solution is simple.  If you need differentiated service, you need to buy a bigger pipe.  Over provision your WAN circuits!  We can’t guarantee delivery unless you have more bandwidth than you need!  Who cares what the packets are marked?  Which, of course, leads to a little gem from everyone’s favorite super villain:

SyndromeEF

Of course, the increased profits from these services will line the pockets of the providers instead of going to build out the infrastructure necessary to support these overbuilt networks.  The only way to force providers to pony up the money to build out networks is to make it so expensive to fail that the alternative is better.  That requires complex negotiation and penalty-laden, iron-clad service level agreements (SLAs).

The solution to the issue of no prioritized traffic is to provide a list of traffic that should be prioritized.  Critical traffic like VoIP should be allowed to be expedited, as the traffic characteristics and protections we afford it make sense.  Additionally, traffic destined for a public cloud site that function as internal traffic of a company should be able to be prioritized across the provider network.  Tunneling or other forms of traffic protection may be necessary to ensure this doesn’t interfere with other users.  Exempt traffic should definitely be the exception, not the rule.  And it should never fall on the providers to determine which traffic should be exempted from neutrality rules.

Tom’s Take

Net neutrality is key to the future of society.  The Internet can’t function properly if someone else with a vested interest in profits decides how we consume content.  It’s like the filter bubble of Google.  A blind blanket policy doesn’t do us any good, either.  Everyone involved in networking knows there are types of traffic that can be prioritized without having a detrimental effect.  We need to make smart decisions about net neutrality and know when to make exceptions.  But that power needs to be in the hands of the users and customers.  They will make decisions in their best interest.  The providers should have the capability to implement the needs of their customers.  Only then will the Internet be truly neutral.

How Do You Spell That?

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I spent a bit of my career on the phone doing support for a national computer vendor. In addition to the difficulties of walking people through opening the case and diagnosing motherboard issues, I found myself needing to overcome language barriers. While I only have a hint of an accent (or so I’ve been told), spelling out acronyms was a challenge. That’s where the phonetic alphabet comes into play

By now, almost everyone uses the NATO phonetic alphabet. It’s the most recognized in the world. The US joint Army/Navy version varies a bit but does have a lot of similarities. However, when I first started out using the NATO version quite a few callers didn’t know what Lima was or giggled when I said Tango.

I decided that some people have much more familiarity with first names. This was borne out when I kept using Mary for “M” instead of Mike. People immediately knew it. Same for Victor, Peter, and so on. So I cobbled together my own Name Phonetic Alphabet.

A – Adam
B – Barbara
C – Charlie
D – David
E – Edward
F – Frank
G – George
H – Harold
I – Irwin
J – John
K – Kevin
L – Larry
M – Mary
N – Nancy
O – Oliver
P – Peter
Q – Quincy (or queen)
R – Roger
S – Sam
T – Tom (my favorite)
U – Umbrella
V – Victor
W – William
X – X-Ray
Y – Yellow
Z – Zebra

Finding a name for Y and Z was pretty difficult, but everyone knows Yellow and Zebra. I was tempted to use Zander, but the more popular version of that name from Buffy the Vampire Slayer was spelled Xander. No sense confusing folks. As for X, if you don’t know X from the sound we need to have a chat.

Was it a duplication of effort? Certainly. But it works universally with everyone I’ve ever talked to, including children. It makes “Roger Adam Irwin David” easy to get across to people without trying to remember Romeo and India.

The key to communication with others is to find something that works for you.  If you can easily convey your information to someone else, the shortcuts you take don’t matter.  If first names work best, use them.  If drawing pictures works better, use those.  In the end, getting the point across is the goal.