Aerohive HiveAP 20, Руководство по развертыванию

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Chapter 1 Preparing for a WLAN Deployment
14 Aerohive
Associated Access Point Costs
After you determine how many access points you need, it becomes simpler to determine the other costs involved
with deploying Wi-Fi because most are driven by the quantity of access points. These costs include the following:
• Installation and Wiring
• CAT5 – CAT5 wiring is required for all HiveAPs acting as portals.
1
One advantage of Aerohive Networks is that
you can deploy HiveAPs in a mesh to avoid some of the wiring costs.
• Power – Power lines are required for all HiveAPs acting as mesh points.
2
Portals receive power through
power lines or through Ethernet cables by using the Power-over-Ethernet (PoE) option.
• Installation – HiveAPs can simply snap into standard dropped-ceiling environments. However, if the
installation is in a warehouse or any environment without dropped ceilings, consider the installation costs.
• Infrastructure: PoE Switches
You must cable every HiveAP acting as a portal to a switch port. For PoE, there are several considerations:
• 802.3af – The current PoE specification provides enough power for all 802.11a/b/g access points.
• 802.3at – The emerging PoE specification supports higher power devices like 802.11n access points. This
standard is expected to be ratified at the end of 2008, so products are not yet available.
• PoE injectors and midspans – These save money on switch upgrades by injecting power into standard
Ethernet connections.
• Site Survey and Debugging Software
• For a sizable deployment, you probably will use site survey and debugging software. AirMagnet Laptop
Analyzer and Survey are two products that pay for themselves very quickly. These products enable the
validation of a deployment and allow you to troubleshoot client and access point issues. (For more
information, see the section on
"Operational Considerations" on page 18 .)
• Professional Services
• When deploying wireless LANs, professional services are often required perform site surveys.
• Client Software
• Depending on the deployment, users can use built-in Microsoft Windows, Linux and/or Macintosh client
software (supplicants).
• For better services and troubleshooting, consider a third-party supplicant such as Juniper Networks Odyssey
Client.
Bandwidth Assumptions for Wi-Fi
People frequently talk about how much coverage an access point provides; however, it is capacity — not
coverage — that typically constrains an access point in an enterprise environment. The challenge is not how far the
RF signal can travel (coverage), but how to deliver enough bandwidth to meet the demands of business applications
(capacity). In other words, you might be able to cover an office of 50 people with one access point, but if all 50
people choose to access it at the same time, it will certainly become overloaded. Indeed, if you use the formulas
provided in this paper, you should find the saturation of access points on your campus to be more than sufficient.
Enterprise users are accustomed to speedy switched networks and expect similar performance from their wireless
LAN connections. This is why documenting the size and type of applications that will rely on your WLAN is so critical
to your planning. In short, if you plan for optimal capacity, complete coverage will follow automatically.
1. A portal is a hive member that links one or more mesh points to the wired LAN.
2. Mesh points are hive members that use a wireless backhaul connection to link through a portal to the wired LAN.