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The whole Google debacle - collecting "wireless payload data" with its Google Street Views (GSV) data collection system -  comes down to nothing more than a greed-driven lawsuit disguised as a case of social justice.

Let's face it, the security of wireless data from 802.11 networks has been talked about for years. But if someone is doing  important things on their wireless network and they're not employing a reasonable level of security, then do they really have anyone to blame but themselves? They've opened their data up to anyone and the ones who really want that data aren't going to openly admit that they collected some while driving by, like Google. No, those that want credit card and personal banking information and possibly someone's identity, will sit much farther away, use directional antennas and collect data for much, much longer than Google does during a GSV drive-by. That's the only way to get meaningful data.

To further illustrate this point, let's assume the GSV vehicle drives so close to someone's house that it passes an AP within a few feet. Let's assume the vehicle is following a typical residential speed limit of 25mph as it drives directly by the AP. A typical AP has a range (and a generous one at that) of a few hundred feet in either direction, that's about 400 linear feet, again assuming the GSV vehicle has driven right up to the AP. At 25mph, the vehicle can travel the 400 feet by the AP in just a little less than 11 seconds. So at best, Google has collected 11 seconds of data, assuming that the person was online at that specific time and that they have completely ignored all pleas by every 802.11 device manufacturer to use wireless security.

The issue, however, is that Google has no idea what channel anyone's AP is set to, so it can't drive by scanning on just one channel. It needs to scan all of the available channels to collect the data that's really of interest, namely whether or not there's an AP around, its network name, and the channel it's broadcasting on. In the 2.4 GHz band there are 11 channels (in the US) and in the 5 GHz band there are typically 8 (again, in the US). Assuming they need to scan through all of these channels, data is only being collected on an individual's specific channel 1/19 of the time, reducing the slice of data that has been collected by Google to less than 0.6 seconds. Perhaps some critical, unsecured data did cross the network in those 0.6 seconds, but that data is now combined with similar data from thousands upon thousands of other users. This sure doesn't sound like the most effective solution to try to get access to user's critical wireless data.

So in the end it's not about data privacy, it's about greed. Could Google have been a bit smarter and not collected the payload data? Well sure they could have. But is there anything malicious going on here? Only on the part of those trying to hide behind data privacy invasion for financial gain.

What's not even considered in this debacle is all of the real data Google does collect, freely and with all our consent, every time we surf the web ...

Roaming occurs when a handset moves out of the range of one access point into the range of another. It gives users the mobility to move around within a local coverage area and still be connected to the network. However, roaming is one of the primary reasons why users experience problems on wireless networks. Excessive roaming times lead to poor quality for voice and video over wireless and can lead to dropped calls or data connections.

Roaming usually involves a channel change, but that depends on the type of technology deployed. If it's a multi-channel architecture, which is most likely the case, a channel change is required. When roaming occurs, the client needs to be re-authenticated and re-associated with the new access point, which takes longer than 150 milliseconds in most instances, especially when advanced features like WPA2 and WMM are in use. Most organization's wireless networks are outfitted with multiple access points (APs) and users can experience poor signal strength and performance despite proper coverage in the area if the client is connected to the "wrong" AP. Even in the most modern, centrally managed systems, the wireless client is the one who decides when to switch from one AP to another. This decision is typically determined based on the current signal strength and is executed by the underlying software controlling the wireless client radio (the "supplicant"). This software is different from manufacturer to manufacturer and from device to device, so the way the decision to roam is made varies widely. In most cases, the wireless client will wait too long and as a result the available signal strength lowers, before the client switches to an AP with greater signal strength.

New and improved standards are available that specify the conditions for "fast roaming," enabling transitions that take as little as 5 - 10 milliseconds. These specifications include:

• 802.11i - with opportunistic key caching so there is no re-authentication step
• 802.11r - fast BSS transition, which optimizes the hand-off as clients move from one access point to another
• 802.11k - radio resource management of WLANs allows re- authentication to be maintained between multiple APs and has predictive capabilities

These new standards (802.11i isn't new, but it's still part of an improving situation for roaming) allow APs greater control in determining when roaming should occur and the APs are more in tune with the current performance of, and demands on, the wireless network. However, this situation is even better when the overall wireless network is under the control of a centralized manager. The issue is that adoption of 11k and 11r has been very slow, especially in wireless clients, and until adoption increases significantly users will continue to suffer slow AP transitions when roaming, leading to poor voice and video over IP performance.

In the meantime, the best approach is to carefully monitor and analyze the roaming activity on your network. Obtaining a complete and accurate view requires real-time aggregation of data from multiple channels and APs, with integrated analysis that leads to detailed reporting - who is roaming, how long each event is taking and what does the average look like for each AP. The end result is simple, yet the process is complex, demonstrating why proper network analysis tools are key to staying productive. 

The recent approval for Yahoo to build a massive campus in the heart of Silicon Valley is the perfect example of how wireless networks can grow and evolve. The sprawling campus will consist of thirteen six-story buildings across 3-million square feet. As a result, the 12,000 Yahoo employees will likely become much more dependent on wireless access, demand it from more locations and expect to have the performance and reliability characteristics of the wired network. There are several issues to consider in a wireless campus environment. As new standards come into play like fast roaming, capacity will become even more of an issue. As more people try to access the network in one area, density will increase and put significant strain on the access point resource. Security is always an issue but in a wireless network environment, it's more about the nature of those on the network and their desire to cause harm. Besides coverage, capacity, density and security issues, below are some key considerations for Yahoo and other enterprises that have distributed wireless worlds.

1. Take advantage of a single vendor's access point management system

These management systems are key in a distributed world. Before, there were wireless monitoring vendors called overlays, which offered additional sensors to access points deployed in the network. However, they were costly in terms of power, equipment and network drops. With access point management systems, companies have access to software that can control channels and power on the fly. Depending on the amount of traffic and people accessing one particular point, the power can be adjusted appropriately.

2. Keep an eye on the spectrum

There are still several interferers out there. 802.11n uses an unlicensed spectrum meaning a lot of other technologies share that same spectrum including Bluetooth, cordless phones, video cameras and microwaves. It's important to be aware of interferers, know what they are and how to manage them.

3. Don't forget about troubleshooting

Monitoring the network through access point management systems isn't enough. It only indicates trouble - it doesn't troubleshoot and solve problems. Being at the scene isn't always effective with campus wide networks, especially when you have satellite offices or are spread across acres of land. Enterprises need an analysis and troubleshooting capability on top of management that can be distributed. This can be done through purchasing additional software probes with wireless adapters. Another option is to leverage the network that is already in place by switching thin APs into promiscuous mode, where their only purpose is to receive and collect packets to be analyzed. Lastly, enterprises can equip network USB hubs with wireless adapters that plug into the Ethernet network. This makes the network transparent and businesses can access adapters to use along with their network troubleshooting software anywhere on the network.

Online mobile VoIP (or VoFi) is coming. In-Stat anticipates 171.3 million users by 2013, with annual revenues projected at $10.8 billion ("Mobile VoIP - Transforming the Future of Wireless Voice; In-Stat In-Depth Analysis," Frank Dickson, Sept. 2009). Previously on our blog we've talked about why VoFi and why now, specifically the benefits of VoFi. Now we'll focus on VoFi monitoring, analysis, and troubleshooting.

Before you panic, take a deep breath. Analyzing VoFi traffic is basically the same as analyzing VoIP traffic. Remember though that wireless exacerbates factors such as jitter, latency, and packet loss that affect VoIP. Watch Using VoIP Metrics to Identify Network Problems for the specifics.

Begin at the Beginning: Your End User's Call

When problems arise with VoIP or VoFi applications, you start in the same place. Your first step - before you begin to worry about statistics or packets - is to take the time to listen to representative calls. You want to hear what your end users are experiencing. Your ear will reveal telltale signs of latency, jitter, and packet loss. Be sure your VoIP analysis application supports playback of call audio, specifically the playback of individual RTP streams as well as the playback of the complete call. Without the audio, you can spend hours tracking down problems that aren't due to either the application or the network - for example, clicking due to a damaged handset.

Take Your Network's Pulse

Once you have listened to the call, you'll want to take a look at what's going on in your network.

Figure 1: Overview of Network Health

Immediately you see what you heard - the call quality was poor. The Mean Opinion Score graph gives an average over all calls occurring on your network. In this example there's just one call, so you see the average for the duration of that call.

Dig Deeper

With Expert Events you're able to verify what your ear told you.

Figure 2: Event Summary

With this call, you can see that there are a lot of physical errors: late packet arrival, retries, out of sequence packets, packet loss, excessive jitter, and more. With the cause identified, you can quickly begin to fix the problem. Looking at the call in its entirety, you'll notice the call is closed, it had a successful ending - meaning the call wasn't truncated - what CODEC was used, how long it was, and what the Mean Opinion Score was.

Figure 3: Call Statistics

In this example, the mean opinion score of 2.5 lets you know that the quality of the call was pretty poor. In the media view, you can drill down into each segment leg to determine why the quality was poor.

Figure 4: Call Details - R Factor, Mean Opinion Score, Packet Loss Percentage, One Way Delay, Etc.

Understand the Differences between Wired VoIP and VoFi Calls

The next two figures show both a Wired VoIP call and a VoFi call packet-by-packet. (For an in-depth discussion of these calls, watch Anatomy of a VoFi Call: Packet-by-Packet.) You'll notice that they're pretty similar. The protocols used are different and with VoFi there's the additional step of authentication.

Figure 5: The Anatomy of a Wired VoIP Call

The differences involve: wireless segments instead of wired segments; signal interference; and wireless roaming.

Figure 6: The Anatomy of a Mobile VoIP (VoFi) Call

Learn More

Last week in Toronto, Joe Habib, Director of Global Services, presented "QoS of IP Telephony: Slaying the Three-Headed Beast of Jitter, Latency, and Packet Loss" at IT360. His presentation (PDF) is now available online. If you're interested in ensuring QoS for your current (or future) VoFi deployment, you should definitely check it out.

In the presentation, you will learn:

• What six factors contribute to poor voice quality
•  How to establish metrics for evaluating VoIP call quality
• How to balance high-speed, bursty data requirements with requirements of high quality voice calls
• How to capture data for VoFi Analysis and use VoIP metrics to identify developing problems
• How to analyze a VoFi call packet-by-packet and verify voice quality with call playback

The use of VoFi, or Voice over Wireless, has been rather limited. But now, with the newly ratified 802.11n standard, we're expecting to see a surge of interest in this technology since 802.11n and its increased throughput and range is what makes VoFi feasible. 

Three benefits of VoFi are:

• Reliable coverage
• Moving billable, cellular minutes to Wi-Fi
• Increased mobility
  

We all continually suffer through the issue of poor cellular coverage indoors, whether at home or in the office. VoFi and VoFi enabled phones provide the capability to transition calls and data activity from cellular to Wi-Fi when in range of an 802.11 network. Since 802.11 is typically deployed to cover indoor spaces, like your home and office, call and data quality will be dramatically improved indoors with VoFi enabled technology.

An added benefit of transitioning a call to your 802.11 network is that it reduces cellular usage, saving minutes on pay-per-minute plans. Granted, this hand-off is still being worked out between carriers and equipment manufacturers, and may not result in a complete minute-for-minute reduction in usage, but more than likely some level of savings will be realized, allowing you to much more quickly capitalize the expense of an 11n upgrade by eliminating some of your billable cellular traffic and carrying it on your 802.11 network.

802.11 has always been about mobility, but up until now it's been manifested more in being able to move from your office to the conference room with your laptop and maintain connectivity. VoFi significantly extends mobility by including voice communications as well. You no longer need to be tethered to a desk phone, or limited by the base-station range of a cordless handset. Wherever there's 802.11 coverage there's voice coverage. This technology was already in use by some industries, large retailers for example, allowing customer service reps to wander the store while helping customers. But 802.11n and VoFi will take this to the mainstream, both in the office and at home.

A key element of VoFi, of course, is the voice component. It's very similar to VoIP in that it's susceptible to jitter and latency, and thus dropped calls, interruptions, and other issues. As a typical wireless network has more latency and interference than a wired network the susceptibilities are that much worse. So with this new technology comes new problems. Are you prepared to manage your new VoFi environment?

On November 18, we're hosting a webinar to explain how best to manage your VoFi environment.

As Joanie Wexler points out in her recent Network World article "Prepping for (finally!) a standard 11n world," the imminent ratification of the 802.11n standard will push enterprises to be more serious about investing in 802.11n. Though some early-adopters have already jumped in, either just to test the waters or because their wireless application plans demanded increased performance, most enterprises have been holding off for the final ratification. For those enterprises entering the 11n water for the first time, the Network World article offers some good preparation tips, whether your entry is from the 3m board or a slow stroll in from the shore.

 

In addition to the tips already offered, several other important points come to mind as you prepare your entry. And you guessed it, our tips center around network management.

 

First, the benefits you'll realize as you move towards 11n will likely have you rethinking the way you use wireless, so what better time to also rethink how you  manage wireless. It goes without saying that your wireless management infrastructure will need to be upgraded to include 11n. Some management applications are just getting there, while others, like OmniPeek, have been there for many years already with a substantial amount of real-world testing, not to mention the use of OmniPeek as part of the Wi-Fi Alliance 802.11n interoperability testing. A move to 11n will most certainly include a move to WPA2 for security, if you haven't already made that move, increasing the need for a network management solution that handles both wireless and wired traffic simultaneously so you can monitor your 802.1x authentication all the way back to the wired sources. And with the increased bandwidth of 802.11n, you'll likely be considering applications like voice-over-wireless, which will require additional measurement techniques like wireless roaming to ensure proper operation of your network and ensure wireless call quality. Basically the message is this: plan for wireless management up front as you make the transition to 11n and make sure your wireless management solutions meet the demands of the new applications you intend to deploy.

 

Second, this is an excellent time to consider HOW you plan to monitor the wireless network, either for troubleshooting or 24x7 observation. Wireless networks are becoming much, much larger, and the days of walking around with a laptop running wireless analysis software to do troubleshooting are drawing to a close. However, wireless networks still require a "point of presence" to do adequate monitoring and certainly any troubleshooting, meaning data must be collected near the source of the reported problem. "Overlay" networks have been the standard solution for the past several years, but this is expensive solution requiring duplicative hardware and network resources (network drops, router ports, etc.). This can be mitigated during your 11n planning by designing in just a bit more density in your AP deployment and then relying on wireless management solutions that can leverage deployed APs and turn them sensors when monitoring or troubleshooting is required. This solution is highly cost-effective since the additional density typically only results in about a 10% increase in the number of APs, much less than the number of dedicated sensors you would need to deploy, and every AP can be put to use in the network resulting in even better network performance when not in use as sensors. This is an extremely important consideration as you roll out a new 802.11n deployment and the cost savings over a traditional "overlay" solution can be substantial.

 

So, whether you're diving in head first or just putting in your little toe, this is the time to reconsider not just network upgrades and the new applications you wish to introduce, but the new management challenges for the network as well. The increased throughput, increased mobility and increasing integration between your wireless and wired network put new demands on your wireless network management solutions. Make sure your solution has already proven that it can meet these demands. OmniPeek has been doing this for years.