Aerohive HiveAP 20, Руководство по развертыванию

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Chapter 1 Preparing for a WLAN Deployment
10 Aerohive
A
SSESSING
Y
OUR
R
EQUIREMENTS
To get started with your Aerohive WLAN installation, examine the basic requirements of your implementation. First,
consider who your stakeholders are and take the time to fully understand their access requirements. Talk to
department managers within your organization and make sure everyone has documented the full complement of
potential users of your network. Check if the applications are standard employee applications or if there are other
requirements, such as access for guests or consultants.
Next, make a complete list of the application types that your Aerohive network will need to support. Begin your list
with mission-critical applications, paying special attention to those that generate high levels of traffic and those
requiring deterministic behavior. Identify applications with heavy data requirements and expected service levels.
Demanding applications such as voice and video will require a higher density of access points. Many enterprises are
investigating the potential of VoWLAN (Voice over WLAN) in the hopes of integrating mobile phones and IP-PBX
systems. Doing so requires an evaluation of other data transmission types that can disrupt the quality of voice
conversations. Because voice traffic is sensitive to network jitter and latency, an inadequate number of access
points can degrade quality. To the user, excessive jitter and delay can cause clipped conversations or dropped calls.
Additional quality and reliability issues might arise when transmitting video, such as for training video or
surveillance operations, because of the sheer size of the data stream.
Other applications such as network backup and file transfers can also have an impact on the network. Therefore,
take into account any bandwidth-intensive applications if you expect your mobile workforce to be accessing the
WLAN while these applications or services are occurring.
Considering the above issues will result in a more informed — and therefore more successful — deployment plan.
P
LANNING
This section reviews the fundamental elements for planning your WLAN deployment. This includes conducting a site
survey, both for an upgrade from an existing WLAN and for a completely fresh
— or greenfield — deployment.
Upgrading from Existing Wi-Fi
If you are upgrading to Aerohive from an existing WLAN, you already have plenty of data about how your current
network is performing. This information can lead to more informed decisions about your new implementation.
To begin, perform a quick site survey with the existing access points in place. If they are less than three years old
and support 802.11g, their coverage and capacity should be equivalent or slightly lower than the Aerohive 802.11g
radio. If the coverage is correct and has the appropriate density for your deployment, then you simply need to
replace one set of access points with a new set of HiveAPs. However, this scenario is rare because network upgrades
are usually done to improve capacity and to augment the existing layout with a denser deployment of access points.
Be sure to take note whether your existing network uses "fat" or "thin" APs (access points). A "fat" AP is an
autonomous or standalone access point, which contains the intelligence and capability to connect to any Ethernet
switch. With a "thin" AP, most of the intelligence has been removed and replaced in a centralized WAN controller. A
fat upgrade to Aerohive HiveAPs is very natural. Generally, with fat APs you simply need to unplug the existing ones
and plug in the new HiveAPs and provision them. With this approach, you can maintain or enhance all existing VLANs
and security policies. This is a huge advantage over migrating from fat AP to controller-based solutions because you
typically need to re-architect the network.