By Brian Boyko

"Jesus has come back, and he's a phone now."

The Apple iPhone might not be the second coming, but it will certainly be popular. Already the Web is being inundated by speculation, information, mis-information, rumor, innuendo, and anyone with an opinion on Apple writing about the iPhone.

So we thought: Why buck the trend?

The truth is that when this device comes out, many people are going to buy the iPhone, they will use it at their jobs - including those in a corporate IT environment - and that means it is going to become the responsibility of the IT manager.

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Continue reading "Why Apple's iPhone means more work for the IT department" »

by Jeff Hicks

Voice over IP (VoIP) is a hot topic in enterprise networking - mostly because it's a challenge. In implementation, VoIP employs a number of different protocols, and has a unique set of performance requirements that make it a challenge for any data network. Examining VoIP protocols should give someone a basic idea of the performance requirements that VoIP places on the network.

First, there's call setup, which sets up everything needed to make the telephone connection between the caller and the recipient (or “callee”). This requires protocols that enable dial tone, number lookup, ringing, and busy signals before the call even occurs. In addition, the call setup protocols handle things that happen after the call - any resource cleanup and statistic reporting.

Call setup protocols use either TCP or UDP to transfer data during the setup and takedown phases of a telephone call. The messages are sent back and forth between the caller, recipient, and call server using well-known ports. For calls that travel between the VoIP network and the Public Switched Telephone Network (PSTN), the call server will converse with a VoIP gateway using the call setup protocol. There are many different call setup protocols, some standardized and some proprietary. Let’s discuss a few of these.

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Continue reading "VoIP Protocol Basics, and Why VoIP Consumes More Bandwidth Than You Might Expect." »

Prof. Christopher Yoo, Vanderbilt University School of Law

Professor Christopher Yoo joined the faculty of the Vanderbilt University School of Law in 1999, and his research focuses primarily on how technological innovation and economic theories of imperfect competition are transforming the regulation of electronic communications.

In addition to clerking for Justice Anthony M. Kennedy and working at the law firm of Hogan & Hartson under the supervision of now-Chief Justice John G. Roberts, Jr., he has also published "Network Neutrality and the Economics of Congestion" [PDF] in Georgetown Law Journal, and "Beyond Network Neutrality" [PDF] in the Harvard Journal of Law and Technology.

Thanks to Network Performance Daily for giving me the chance to discuss some of my ideas and to the various readers on Network Performance Daily and Slashdot.com for their comments. The comments suggesting that QoS and optimizing networks have nothing to do with network neutrality are a testament to how much the network neutrality debate has changed over the last year and a half. For example, the network neutrality Policy Statement issued by the FCC in August 2005, which remains the focus of the network neutrality conditions in the AT&T-BellSouth, Verizon-MCI, and SBC-AT&T mergers, it focuses on providing differential service on the basis of application and devices as well as content source.

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Continue reading "Net Neutrality: Professor Yoo Responds to Comments" »

Art Brodsky, Communications Director of Public Knowledge

This article continues our series on Network Neutrality.

We asked him to share his thoughts on Net Neutrality with us.

Net Neutrality, as we [at Public Knowledge] understand it, would return to communications law and regulations the concept of non-discrimination. This has been part of communications law since the 1934 [Communications] Act [PDF], until it was partially repealed, in essence, by the FCC last fall, for high speed services.

What we're trying to do is make sure that the carriers, whether they be telephone, cable, broadband-over-power-lines, etc., aren't in the position of picking "winners and losers," substituting their judgment for those of the customers.

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Continue reading "Network Neutrality Debate: A case for Net Neutrality" »

[Editorial Note: As of January 7, 2006, we have been contacted by Prof. Yoo, who has said that he sent us some clarifications and corrections that we did not receive before publication deadline. As such, the article that appears in this space has been retracted. An explanation of what occured and the corrected version of the article that contains Prof. Yoo's corrections can be found at this location. Those with questions about the article can e-mail brian.boyko at netqos dot com with any questions or concerns.]

On NetQoS's internal boards, this news item from ZDNet prompted a discussion over Net Neutrality; and we had various questions and concerns about how recent developments would impact the Internet and our position as a network monitoring company. Below are some of the most insightful comments from the discussion that ensued.

Because it is a contentious issue, we have invited a few outsider experts to provide commentary. Tomorrow we will have commentary from Prof. Christopher Yoo at Vanderbilt University Law School, and we plan to follow it up in the future with commentary from other Net Neutrality issue experts as their schedules may allow.

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Continue reading "Network Neutrality Debate: An Introduction and Discussion" »

By Ben Haley

I’m a developer for NetQoS, and I’ve been mulling over the idea that Cisco is planning to take the IOS in their routers and break it into different modules, which they can then provide separately. As a developer I am always interested in architecture, but as a customer do I really care how the code is implemented? After all, I buy a router to direct traffic. My main interests are that it does this reliably, quickly and for a reasonable cost. What difference does it make if the IOS comes feature-by-feature or in a single package deal? In this case I believe the change will be very positive.

The IOS is the Internet operating system for the router. Everyone tends to think of the router as a piece of hardware you plug in, but it’s really a specialized computer that has an operating system on it that can be tweaked to do different things. Every switch and every router has some type of operating system built into it. In fact, people have been able to figure out how to install Linux on a few models of consumer routers and add new capabilities.

Moving to a modular system provides some interesting ideas. For IT administrators, it might increase the cost, or if relatively few features are needed, save money. (Cisco, I think, tends to make money on the hardware, not on the software.) Either way, it’s an interesting concept to say “How would you do this, and what would be the impact?”

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Continue reading "Thoughts on Cisco's Modular IOS" »

by Kevin Davis

It might not be possible to understate the importance of network visibility.

Without visibility, the last words captured on the black box flight recorder are likely to be "What's a mountain goat doing way up here in this cloud bank?" (Apologies to Gary Larson.)

Imagine attempting to manage network performance across an enterprise without knowing who is using the network, when they are using the network, and without knowing if the routers and switches are running at their limits, or are failing intermittently. Utter chaos.

So, how do you get visibility into your network?

Well, the main areas of visibility required to effectively manage a network for performance may be divided into three major categories:

End-to-end Response Time: On a per-application basis for business critical applications-the ability to understand the performance the user is experiencing, as well as to identify and isolate the source of a problem to the network, server, or application
Traffic Flow Data: The traffic utilization of network links (for WAN, MAN, and LAN) from SNMP and flow analysis from NetFlow monitoring or IPFIX data
Device Performance Information: The status and utilization of network devices themselves (especially routers, switches, and firewalls) via SNMP

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Continue reading "Network Visibility Techniques" »

For more information on this topic, you can download our Tech Brief on Cisco WAAS, available here

by Steve Fulton

Users expect a ubiquitous and instantaneous network, as well as consistent application performance. This, combined with a proliferation of business critical, Web 2.0, (and recreational) applications that consume precious WAN bandwidth, forces IT to get very creative in squeezing more performance out of existing infrastructure.

Hence the red-hot market for application acceleration and WAN optimization products that address WAN performance problems caused by latency, congestion, and applications (such as WAFS and CIFS) that were designed for the LAN and now have to traverse the WAN due to data center consolidation.

Cisco shook things up in late 2006 with the introduction of WAAS-short for Wide Area Application Services-technology that is transparent to the underlying network infrastructure. According to Cisco, WAAS combines WAN optimization, acceleration of TCP-based applications, and Cisco's Wide Area File Services (WAFS) in a single appliance or blade.

WAAS addresses problems related to traffic congestion that need some sort of optimization done at the branch. It complements Cisco's Application Control Engine (ACE), which is a data center optimization product that integrates server load balancing, application security, and unique virtual partitioning capabilities.

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Continue reading "WAAS Up with Cisco's WAN Optimization Initiative?" »

Compiled by Brian Boyko

We (and many other experts) believe that there needs to be an industry discussion between developers and networking groups, because it seems that people - at least the people we come in contact with regularly - talk often about how applications designed and tested to run over a LAN perform horribly over a WAN.

Because this dialogue doesn't seem to be happening much yet, we've decided to try to take the initiative and help jump-start the discussion between appdev teams and networking groups.

Despite the fact that this blog deals with network performance, and as such would most likely appeal to IT managers, network engineers, and the occasional CTO/CIO, this blog's earliest success was an article by Carol Schiraldi speaking about games programming. That article made it on the front page of DZone - it's kind of like Digg for developers. While getting a developer audience was entirely unexpected, that article is what convinced us that we were starting to produce some compelling content, and caused us to set our sights very high. Over the past week, we've received over 15,000 unique visitors; which is not bad for a site that has been up less than 6 weeks!

On the other hand, some members of DZone had complained - fairly, in my opinion - that much of what we wrote didn't really affect developers. Although we got back on their front page again with an article by Russell Wilson regarding UI development, DZone has mostly remained a bit aloof to our offerings - and who can blame them. So we asked one of their editors, Lowell Heddings, how we could better serve the DZone community (and by extension, the developer community.) He had this to say:

"My main question for network engineers is... aren't routers boring? =P"

I'm pretty sure he was trying to blow us off. But he's got a point. Aren't routers boring? So I actually posed this question in a company-wide e-mail. Here are some of the best responses:

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Continue reading ""Aren't Routers Boring?" the developer asked." »