Monday, April 23, 2007

802.11n- making sure everyone forgets about 802.11a

Every meeting I attend I get asked the same question right at the onset- "What about 802.11n?" My first response is usually "What about it?" followed by "What do you know about it?" I would usually dismiss these questions as merely knowledge-gathering questions if it were not for the potential purchasing ramifications.

Many people see 802.11n as the wireless technology that is going to finally make it possible for them to get HD video, VoWLAN calls, and all sorts of multimedia traffic at the same time on their computer. After all, the draft plans call for the technology to offer close to 120Mbps of throughput (of course that is the "in-a-vacuum" spec, much like the 54Mb for 802.11a/g). This fire is further fueled by the fact that every month sees the passing of a draft resolution and companies are starting to release 802.11n APs and client cards. This makes it seem that resolution of the debates and the emergence of a draft standard are right around the corner. Unfortunately, nothing could be further from the truth.

It is pretty clear that 802.11n is going to incorporate something called Multiple In/Multiple Out technology, allowing for "full duplex" via wireless. Remember, wireless is a half-duplex technology. With an association to an AP or radio, you can either transmit or receive at any time, you can't do both. 802.11n has promised to change that- by utilizing more channels at the same time and therefore allowing one to transmit on one channel and receive on the other. I won't deny- it is very exciting and the possibilities are there. However, people tend to overlook that the possibilities are already here now- they exist in the red-headed stepchild known as 802.11a.

802.11a made its debut in the consumer market around the same time as 802.11b and was much more expensive. Then 802.11g came out and everyone thought that they were getting everything they would get with 802.11a plus compatibility with 802.11b. The only difference is that because 802.11a is in the less crowded 5.8Ghz space and has more non-overlapping channels compared to the three for the 2.4Ghz range where 802.11b/g reside, it tends to work much better- there is simply less potential interference from other devices (Quick sidenote: try this experiment- set your 802.11b/g channel to 11 and go into your kitchen with your laptop. Turn on your microwave and look what happens to your wireless signal or your ability to send/receive data). Anyway, because 802.11a received such a tepid response, people still tend to ignore it and believe that 802.11n is going to fix all the problems they have with 802.11b/g.

The key question to ask, is what are you currently doing or wish to do that you cannot do with 802.11a? Given the much more open space in the 802.11a range, one can reach high throughput speeds allowing them to do most of the things they desire with 802.11n. Plus, no one is quite sure how 802.11n is going to work within a mixed environment. On its own, 802.11n will give you great results, but in a mixed environment it will have to drop significantly to give equal time to the other clients (much like 802.11g has to do for 802.11b).

Further complicating the issue, is that 802.11n will not work with the same 802.3af Power over Ethernet that is currently being used by companies everywhere. The radios require too much power to drive the MIMO technology and will need to have power adapters until the new PoE standard is adopted. The infrastructure costs to companies alone will be quite huge, and there will not even be a great benefit because true 802.11n clients are not going to be out until the tail end of 2008. Plus, as I mentioned earlier, unless you are in a n-only environment, you are not going to get all the throughput you desire.

"But what about all those wireless routers at Best Buy?" you ask. Well, those are based on the pre-draft standard, and given the number of changes being made on an almost monthly basis, the purchases you make now might not be a simple firmware upgrade to get to the released draft standard. Also, you are probably not running anything in your house that requires such a speedy wireless connection. I currently run 802.11g-only environment, and I get more than enough throughput to satisfy all my needs. The key is to make sure and select the least congested channel (I suggest channel 1) and making sure that you try and get rid of all the b clients in your environment so that you don't have to lower throughput to accommodate for them. In an office environment, look to 802.11a- you can run it over the existing PoE and can also take advantage of the less crowded bandwidth. The performance limitations that exist for 802.11g are not there for 802.11a because it runs on its own radio.

I know I sound like I am pessimistic on 802.11n, but I assure you I await its arrival like everyone else. The misconception is that one should put off wireless investments today to wait for the 802.11n standard to be release in 1.5 years from now. That is the big mistake- the cost to your company will far outweigh any benefits that you will see from the technology. It is not the hardware that drives the moves to new technology, but consumer need and the applications. Eventually you will need it- there is no doubt, but 802.11a can handle everything presently and into the foreseeable future.

Wireless in the city

The debate on Municipal Networks has a long history... though, wouldn't we all like to live in a completely Wired City? How about London?

Friday, April 20, 2007

Ten servers for the price of one... almost.

Server Virtualization is here to stay. VMWare is a great application. Now that we have dual core and quad core servers, is like having multiple CPU's in a single chassis. Well, Server Virtualization means literary that: having multiple servers (each one with its own OS) in a single chassis.

Corporations are enjoying the benefits of managing a single hardware, while dealing with as many as ten virtual servers on that hardware: better Return on Investment, lower Total Cost of Ownership, simpler administration and easier upgradeability are just a handful of those benefits. The value proposition that VMWare brings is tremendous.

Any drawbacks? - a perceived one is the limited bandwidth that those servers will "share". People think that a server typically has one GigabitEthernet interface (i.e. 1 Gbps), therefore when virtualizing it into 10 servers, each virtual server will have to share the one Gigabit connection. Well, that is true; though the beauty is in that you can have multiple GigabitEthernet interface in a platform. As many as you want. Therefore you can link ten 1Gbps interface, and aggregate all the bandwidth.

Another great component of virtualization kicks in: blade switches. This is a switch for your specific server at the data center to avoid installing several GigabitEthernet interfaces. The switch goes straight into the blade server where the virtualization will take place; not connected to the server, but rather connecting the server to the network.

Major benefits? - provide an integrated switching solution which dramatically reduces cable complexity and offer consistent network services like high availability, quality of service and security. All directly to the blade.
As you can probably see, Virtualization can be complex in itself.... though expect to see a lot more of that in the nearby future. We'll probably have virtual desktops at home soon!

Monday, April 16, 2007

Vonage is out!

I believe Vonage will be out later this year, or maybe next year. To me, this is a similar case to what happened to Napster in 2000. This time, is Verizon driving the doom of Vonage.

Now, a lot of people is wondering if this is going to impact Internet Telephony in general. Well, I really think that it will impact it, though not in a definite way. When Napster was taken out of the cyber-map, did that stop file sharing?... not really. Now we have Limewire, gnutella and other technologies. It is probable that the same will happen to Internet telephony: Vonage will be gone, but others will find workarounds on time. We may be able to see a Broadvoice, Packet-8, or Skype survive.

Friday, April 13, 2007

Cisco's position on Net Neutrality

Net Neturality keeps coming up as a hot and controversial topic.Well, I found a great position and I want to share it.
Regulate only if necessary:

Cisco's Position on Net Neutrality

Friday, April 6, 2007

LAN/WAN/VoIP in a box

As announced in NetworkWorld, Cisco recently released the LAN/WAN/VoIP ultimate integration for the small and medium office. Small offices don't have to pay tens of thousands of Dollars for getting a solid IP Telephony key system, with Power over Ethernet switches, and IP Phones.

The products: UC-500 (small form-factor IP Based Key System), CE-500 (Catalyst LAN switches with PoE) , and AP-500/WLC-500 (compact and inexpensive wireless Access Points and Controller).

Key Benefits:

  • Inexpensive
  • Latest and greatest technology: IP Telephony with SIP/SCCP, Voice-Mail, PoE Switch, Wireless 802.11a/b/g
  • Full support from an enterprise level company: Cisco
  • Super easy to manage

Monday, April 2, 2007

Web 2.0 - Why do we need software anymore?

Web 2.0 is truly transforming the software application's industry. A couple of years ago, the hot topic was that Google Spreadsheet will kill Microsoft Office's Excel application. And then Microsoft said that Windows Live will provide word processing, spreadsheets and presentations on a hosted model. All that is possible thanks to Web 2.0.

YouTube, Netvibes,, Google Maps, and Windows Live are some of the player in the revolution. I realized the other day that I am progressively and subconsiously moving to the Web 2.0 model: I use LinkedIn to keep my contacts in order, I use Netvibes as my online based RSS reader to read the news online every day, I use webmail for my personal email, I use to make phone calls over the Internet. Eventually, the entire OS will be online! Video Games are now played online, there are online marketplaces like eBay and There is even a parallel universe called Second-Life.

In the future, corporations will move into that direction (remember my posting on who creates demand these days). They will use online spreadsheets, online word processing, for CRM, and an online based PBX for managing their telephony system. The small fish will start deploying the great Web2.0 model. It is left to see if big enterprises will go that road... probably all these services and applications can be hosted in the companies data center, managed by IT. This is way into the future now. For now, I believe enterprises do not see the value of going into that model... is the best example of a successful model for companies. They are growing very fast, and people is seeing this as a good alternative to large scale CRM applications like Oracle or SAP. It is much simpler for the user, and easier to manage by the IT department.

Another great example is NetSuite. They are an online based accounting provider. Picture it as a QuickBooks online, where you can track coporate expenses, revenue, profit, and maintain all your companies accounting. Big companies are starting to spot NetSuite as an alternative.

The benefit is definitely out there.