Monday, November 5, 2012

The Hotspot, the Throughput and the Gateway #Cisco #WFD3


Sujit Ghosh (TME Manager) set the stage and introduced us to Bob Friday CTO in WNBU. He outlined the topics that would be covered as:
  • Hotspot 2.0
  • 802.11ac,
  • Bonjour Gateway
  • Cisco's Application Visibility and Control (AVC).
Bob Friday kicked off the discussion of Hotspot 2.0 by stating that interoperability is the key word going forward. There are a great many startup companies working to enable information sharing seamlessly. 

Detect, Connect, Engage: bringing enterprise security into the public Wi-Fi space for the first time. 
The Samsung Galaxy was one of the first devices certified on the same day that the Wi-Fi Alliance made Hotspot 2.0 certification available. He mentioned that he is meeting more with marketing personnel at companies rather than the engineering staff. The momentum is to monetize access to the Internet as well as enabling advanced features of a Wi-Fi experience. 3G offload is all about optimizing the connectivity experience of the end users. The Services Notification framework in the iPhone allow you to configure how and when you would like to be notified of events. This also allows venues to interact with your mobile device to send you relevant information about things you would be aligned with your interests. In the enterprise space it is about making workforces more efficient. Streamlining work flows to cut out lost time waiting can be very meaningful to the bottom line financials.

Mark Denny and Damodar Banodkar gave us an overview of the 802.11ac specification as well as a demonstration of the throughput possibilities. 

The 802.11ac module for the 3600 series Access Point is the same form factor as the monitor module that is currently available. They're not waiting for the first clients to ship, they're working with the chip vendors to do client testing as soon as the chips are manufactured. Wave 1 of 802.11ac is 3x3:3, will be available in Q1 of 2013. Speeds capable with 802.11ac clients and the 802.11ac module in a 3600 are 1.3Gbps PHY, 80MHz, 256QAM with optional explicit beam forming support as per the 802.11ac standard. The 3600 AP with the 802.11ac module will require enhanced PoE, 802.3at PoE+, Local power or a PWR-INJ4. The module has it's own independent 5GHz radio, it will utilize the ac module just for ac capable clients. If the main radio in the AP is using 40MHz bonded channels, the 802.11ac module will us 80MHz bonded channels. If the retries counters begin to increase, the 802.11ac module with downgrade to using 802.11n rates. At that point, the internal radio will take over from the module to serve clients.

The initial form factor restricts the use of the module inside a NEMA enclosure since the antennas are integrated into the module itself. There are no external antenna options at this time, but Cisco is giving thought to this option.

Performance metrics for explicit beam-forming will be available by the end of the year, Cisco is waiting on 802.11ac client devices. The MAC throughput is calculated assuming a MAC efficeincy of 70% the defined PHY capability (194 Mbps - 845 Mbps then 2.25 Gbps). Utilizing wider channels are part of the Wave 2 timeline, coming in 2014.
The biggest use cases of 802.11ac will be medical imaging files, offloading of 2.4GHz, collaborative classrooms with HD video as well as High Density "build it and they will come" use cases. There is no information yet on roaming from 802.11ac to 802.11n and what does that do to speeds/distances. This is something that will need to be tested as more 802.11ac client become available. The plan is to use all three radios concurrently and use a channel plan accordingly. The live demonstration of the 802.11ac module and an 802.11ac client (Broadcom chipset) was very interesting to see. No one has ever seen a live demonstration of the data throughput that will be possible as 802.11ac wireless becomes widely available. The client connected at speeds varying 700Mbps to 1.3Gbps, depending on the interference present in the environment. The AP and the client were operating on channel 36, utilizing an 80MHz wide spectrum. Using the Ixia throughput testing software, speeds of 550Mbps were achievable in a real world conference room setting. Duty cycle utilization was upwards of 80% when the 550Mbps speeds were obtained. When asked if there were any further questions, Rocky summed it up best.

Jeevan Patil, 
Damodar Banodkar and Sudhir Jain presented on Cisco's Bonjour Gateway solution. The K-12 and Higher Ed are pushing the need for a Bonjour Gateway, due to the prevalence of Apple devices used in the classroom as learning tools, and as the students bring their iDevices from home to the dorm rooms.

The Bonjour protocol sends multicast packets which advertise and discover services offered by other client devices. It is Apple's service discovery protocol. Some customers want Apple to solve the problem of how to corral the Bonjour service on a network, but the majority of wireless vendors are taking it upon themselves to offer solutions to make the Bonjour protocol behave better in large enterprise networks. Bonjour services do no cross VLAN boundaries without assistance from the wireless infrastructure. 

The Cisco Wireless LAN Controller (WLC) caches Bonjour services on the controller, then the client can be on VLAN X and ask what services are available on VLAN Y. No Bonjour services available may be available on VLAN X, but the WLC can tell the client that AirPlay is available on VLAN Y. With VLAN override configured on the WLC, you can have AirPlay on a single VLAN and enable mDNS Global Snooping on the WLC and configure query status for the service name. This can be set on per VLAN or per interface. The WLC can disallow or allow AirPlay, AirPrint, File Sharing or the App Store.

By snooping Bonjour the WLC can optimize delivery of multicast information. Multicast responses are unicasted to the the clients requesting the service. This implementation is more efficient and does not burden the network with multicast traffic. Only the users that have the device permissions will receive the multicast information based on the locally cached information in the WLC. WLC traffic statistics show there is 80% less multicast traffic generated for four access points when mDNS snooping is enabled on a WLC. The multicast request goes all the way to the AppleTV to check for permissions. The response is unicasted back to the original requesting client.

Cisco was a sponsor of Wireless Field Day 3. As such, they were responsible for covering a portion of my travel and lodging expenses while attending Wireless Field Day 3. In addition, they provided me with a OGIO duffle bag containing a Cisco 3602 Series Access Point. They did not ask for, nor where they promised any kind of consideration in the writing of this review/analysis.  The opinions and analysis provided within are my own and any errors or omissions are mine and mine alone.

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