Cisco Cisco Aironet 3500i Access Point 白皮書
Farpoint Group White Paper – April 2010
Spectral Assurance Total Cost of Ownership
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assurance is thus only a very small percentage of the overall capital cost of any given
installation, and this percentage declines with overall scope. But the CapEx of CIM will
often be much higher than that required in the WAM case, which involves only a
notebook and an inexpensive spectrum analyzer tool.
On the operating expense side, recall how the walking around model is fundamentally
labor-intensive, and often of indeterminate scope and thus of indeterminate cost. It can be
quite frustrating to hunt down intermittent sources of interference (we have significant
direct experience with this kind of work!), and being in the right place at the right time
can never be guaranteed. The CIM strategy eliminates almost all of these costs, and thus
we expect to see overall TCO benefit from centralization.
As we noted above, equally important, but much more difficult to quantify, are a broad
range of potential opportunity costs associated with failures in the network. These can
include lost productivity in the event of user-visible problems or wholesale downtime, as
well as potential consequential costs, including legal and other regulatory violations and
their potentially enormous impacts, the fallout from security breaches and related failures,
and lost prestige, customer confidence, and business that can result from customer-facing
service problems arising from network failures. Even degraded throughput can factor in
here, if such affects the responsiveness of the enterprise. As most businesses are today
heavily dependent upon the corporate LAN (wired and wireless) for essential operations,
it makes sense to implement improvements in reliability – like centralized spectrum
assurance – that contribute to the reliability and performance required to avoid these
potential consequential opportunity costs. The network is, after all, a tool to optimize the
productivity of the organization. Assuring its efficient operation no matter what the
challenge is essential, again why we believe that SA functionality is essential in all
enterprise-class WLAN installations. The TCO differential between any form of spectral
assurance and no spectral assurance capability whatsoever are the large opportunity or
insurance costs associated with all of the exposures noted above. Quantifying these will
depend upon the specifics of a given installation and industry, but they can clearly be
very large indeed. The analysis we will thus focus on below will be limited to a
comparison of the costs of an infrastructure-based spectral assurance vs. the walking-
around model.
TCO of Spectral Assurance Solutions: An Example
While the specifics of any given installation can vary, Farpoint Group, in consultation
with Cisco Systems, has developed a general TCO model (See Table 1) for the
deployment of spectral assurance capabilities in the enterprise. In this model we consider
three specific scenarios: the walking-around model (WAM), as discussed above, and two
variants on the centralized/infrastructure model (CIM). The first of these is a partial
(sometimes called an “overlay”) strategy, which might be used in the case of an existing
deployment, and which is implemented via the addition of some number of spectrally-
enabled APs, in this case the Cisco 3500 series. This type of deployment can provide
continuous monitoring and the location of interferers, the latter enabled via Cisco’s
installation, and this percentage declines with overall scope. But the CapEx of CIM will
often be much higher than that required in the WAM case, which involves only a
notebook and an inexpensive spectrum analyzer tool.
On the operating expense side, recall how the walking around model is fundamentally
labor-intensive, and often of indeterminate scope and thus of indeterminate cost. It can be
quite frustrating to hunt down intermittent sources of interference (we have significant
direct experience with this kind of work!), and being in the right place at the right time
can never be guaranteed. The CIM strategy eliminates almost all of these costs, and thus
we expect to see overall TCO benefit from centralization.
As we noted above, equally important, but much more difficult to quantify, are a broad
range of potential opportunity costs associated with failures in the network. These can
include lost productivity in the event of user-visible problems or wholesale downtime, as
well as potential consequential costs, including legal and other regulatory violations and
their potentially enormous impacts, the fallout from security breaches and related failures,
and lost prestige, customer confidence, and business that can result from customer-facing
service problems arising from network failures. Even degraded throughput can factor in
here, if such affects the responsiveness of the enterprise. As most businesses are today
heavily dependent upon the corporate LAN (wired and wireless) for essential operations,
it makes sense to implement improvements in reliability – like centralized spectrum
assurance – that contribute to the reliability and performance required to avoid these
potential consequential opportunity costs. The network is, after all, a tool to optimize the
productivity of the organization. Assuring its efficient operation no matter what the
challenge is essential, again why we believe that SA functionality is essential in all
enterprise-class WLAN installations. The TCO differential between any form of spectral
assurance and no spectral assurance capability whatsoever are the large opportunity or
insurance costs associated with all of the exposures noted above. Quantifying these will
depend upon the specifics of a given installation and industry, but they can clearly be
very large indeed. The analysis we will thus focus on below will be limited to a
comparison of the costs of an infrastructure-based spectral assurance vs. the walking-
around model.
TCO of Spectral Assurance Solutions: An Example
While the specifics of any given installation can vary, Farpoint Group, in consultation
with Cisco Systems, has developed a general TCO model (See Table 1) for the
deployment of spectral assurance capabilities in the enterprise. In this model we consider
three specific scenarios: the walking-around model (WAM), as discussed above, and two
variants on the centralized/infrastructure model (CIM). The first of these is a partial
(sometimes called an “overlay”) strategy, which might be used in the case of an existing
deployment, and which is implemented via the addition of some number of spectrally-
enabled APs, in this case the Cisco 3500 series. This type of deployment can provide
continuous monitoring and the location of interferers, the latter enabled via Cisco’s