Network and Telecom Strategies Blog

Burton Group 802.11n report - commentary

posted by Paul DeBeasi:

There have been many articles, emails, and blog entries written about the Burton Group report “802.11n: The End of Ethernet?”.  As author of the report, I’d like to clarify a few things.

1. Burton Group takes pride in the fact that we do not do ANY vendor-sponsored research.  We don’t even do vendor-sponsored white papers.  Burton Group clients are predominantly very large enterprises and rely upon our research for unbiased, vendor-neutral research.

2. The report specifically looks at LAN access networks.  Wired Ethernet will be used for many years for inter-switch trunks and data center connectivity.  But, for LAN access, wireless is the future.

3. Speaking of the future, the report is looking at the state of the wireless/wired market in the 2 – 3 year time frame, not in 2007.  In fact, enterprise 802.11n access points are not even shipping yet. I don’t expect RJ45 jacks to be ripped out of the walls.  Instead, we are going to see wireless slowly spread and eventually dominate LAN access.

4. Security is a broad topic so let's break it down.  802.11 networks provide authentication, data privacy, and data integrity.  If you use best practice wireless security (802.1X + WPA2 + AES encryption) you can deploy a wireless network with authentication/privacy/data-integrity that is just as good as a wired network. Sure, WEP was broken (and lots of companies still have WEP) but WEP is not a best practice. If you want strong wireless security, you have to use WPA2. It is true that wireless denial of service is a vulnerability but the real question is what level of risk can you live with and how much are you willing to pay for RF monitoring/mitigation?   Also, don't forget that a wired network is not perfectly secure.  Eavesdropping can occur on a WIRED network too (see http://www.governmentsecurity.org/articles/articles2/ACSI33-5-Emanations-and-Cable-Security.pdf_fl/). 

5. If you use IETF RFC 2544 as the basis for benchmarking, the latency of an 802.11n AP and a Gigabit Ethernet switch is not very different (both are well below the ITU guideline of 150 milliseconds for VoIP).  However, real world latency is impacted by traffic patterns and how the equipment is deployed. It is easy to create situations where wireless latency is high. For example, if you use 802.11b clients and configure the AP to allow connections even with very weak RSSI, then you are going to bring the network to its knees. However, many of the new 802.11n enterprise APs will have two radios.  A preferred configuration is to operate one of the radios in "mixed mode" @ 2.4 GHz (ie, compatible with 802.11g/b) and run the other radio @ 5 GHz for 802.11n laptops only.  In addition, the APs should be configured so that very weak RSSI signals are disconnected. Laptop clients tend to be "sticky" and hang onto their AP connection even when RSSI is weak. 

6. It is certainly true that 802.11b/g/a APs can exhibit instability. By "stability" I mean wireless connection reliability.  802.11n and best practice network design can alleviate a lot of the problems. Much of the instability with 802.11b/g/a networks is caused by multipath and co-channel interference. 802.11n makes use of MIMO (multi-input / multi-output) radio design that takes advantage of multipath to actually boost throughput and reliability. After decades of research MIMO technology will now be widely deployed in 802.11, 802.16 (WiMAX) and cellular networks. In addition, dense deployment of lightweight APs (& controllers) will improve stability through load balancing and dynamic radio management. Co-channel interference can be reduced (but not eliminated) by using 5 GHz spectrum and modern Wireless LAN systems (controller + APs). In addition, 802.11k (radio resource management) and 802.11v (station control) will be ratified by the IEEE in the next 12 - 24 months.  Taken together these two new standards will make a WLAN more like the cellular network (where the network controls roaming - rather than the station) and will greatly increase wireless stability.

Cisco and Microsoft - A Shared UC Vision?

posted by: Mark Cortner

I’ve been contact by several clients over the last week regarding the recent webcast featuring Cisco’s CEO, John Chambers, and Microsoft’s CEO, Steve Balmer. The stated purpose of the event was to enable the top executives from both companies to articulate their vision for the future of technology and to discuss their joint plans to strength the level of collaboration between the two industry leaders and interoperability between network and software solutions.

The webcast highlighted seven top areas of collaboration: IT architecture, security, management, wireless and mobility, connected entertainment, small and medium-sized business, and unified communications. The last topic, unified communications (UC), has been the focus of my recent discussions with our enterprise clients. The perspectives shared by Cisco and Microsoft during the webcast generally exhibited a shared vision, and perhaps most importantly, the execution of these visions provide complimentary product opportunities and solutions roles which may served by each vendor.

But in the area of UC, while one could argue the vision was shared, the two industry titans undoubtedly have dramatically differing views on how to deliver and manage the suite of communication applications comprise a rich UC solution – a network versus software-centric architectural model. The key message related to UC was that interoperability between Cisco’s and Microsoft’s solutions, is recognized as a significant customer concern and that interoperability would be “customer-driven”.

The concern for many enterprises today is that as they listen to and receive proposals from Cisco and Microsoft, the unified communications product strategies that each is currently following has major areas of overlap. While some customers are open to a single vendor sourcing approach to UC, most anticipate a multi-vendor, best-of-breed approach. Clear assurances of specific interoperability between Cisco and Microsoft will have more of an impact on the pace at which enterprises execute their UC strategies and deploy solutions than the technology itself and the availability of products. The bottom line is that having Cisco and Microsoft share the stage and discuss their intentions in this market was vital to addressing enterprise concerns, but both vendors should understand that demands for more specific interoperability details and shared product roadmaps must be committed to by each vendor to accelerate enterprise adoption and implementation of UC solutions.

802.11n - Ethernet Killer (eventually)

posted by: Paul DeBeasi

The IEEE 802.11n draft standard is the beginning of the end for wired Ethernet as the dominant local area network (LAN) access technology.   However, this does not mean that we are going to see a precipitous erosion of the wired Ethernet switching market.  The fact of the matter is that enterprise APs will not be generally available until the fall of 2007.  Vendors are still working on testing their products, fixing bugs, and tuning performance. 

When these products finally begin to ship, they will be used predominantly in pilot programs.  These early products will be more costly than 802.11g/a products and enterprises will want to “kick the tires” before committing to products based upon a draft standard.   In addition, these early products will not achieve the full potential of 802.11n.  So, at least in the near term, Mike Disabato is correct when he says that 802.11n is not ready for prime time. 

However, just wait until 2008 and beyond!  Prices will fall as volumes rise and early jitters over the draft status of 802.11n will fade away as the Wi-Fi Alliance continues their certification program.  In addition, refinements in system silicon, radio design, network control, wireless security, and power management will significantly improve 802.11n products to the point where it will begin to erode the switched Ethernet market. 

The skeptics are wrong.  Wireless WILL replace wires.  It’s just a matter of time…