Tolly Report #211100 August 2011 Commissioned by Xirrus…tolly.com/ts/2011/Xirrus/TCO/Tolly211100XirrusWLANCostandCapacity... · August 2011 Commissioned by Xirrus, Inc. Executive

© 2011 TOLLY ENTERPRISES, LLC

Enterprise Wireless LAN Deployment

Cost and Capacity Analysis: Xirrus vs. Aruba Networks and Cisco Systems

Tolly.

Tolly Report #211100August 2011

Commissioned byXirrus, Inc.

Executive SummaryOver the past decade, wireless LAN technology has truly revolutionized “last hop”

connectivity to the end user. The growing popularity of mobile devices like laptops,

smartphones and tablet computers consuming high bandwidth, mission critical

applications (like cloud services and video streaming) is impacting the requirements of

the wireless LAN infrastructure in the enterprise. Density, capacity, and resiliency of the

Wi-Fi solution are becoming critical success factors for the network while as in the past,

simply providing secure access would suffice. Wired LAN has always had an advantage

over wireless LAN/Wi-Fi solutions in terms of the sheer bandwidth that can be delivered

to the end user. With the advent of the IEEE 802.11n technology, Wi-Fi products are now

becoming a viable alternative to a wired LAN, providing increasing resiliency and

performance surpassing that of Fast Ethernet, promising ‘to cut the cord’, in businesses

around the world.

Network architects considering deployment of Wi-Fi solutions need to be aware that not

all 802.11n Wi-Fi products are architected the same, nor do they offer the same level of

performance. Customers need to consider various factors like the one-time capital

expenditure (CapEx) required for hardware and software components of each solution,

as well as the ongoing operational expenditure (OpEx) items such as maintenance and

power costs. In addition to the acquisition and ongoing costs associated with each

solution, customers need to also factor in the costs of any switching infrastructure

upgrades, cabling infrastructure upgrades, etc. required to implement a solution. Apart

from these easily-quantifiable costs, there could be ancillary but substantial costs

associated with items such as: site surveys, end user training, network performance and

coverage optimization that will vary from one deployment to another.

Xirrus Wi-Fi Arrays, available in 4, 8, 12, and 16 radio models, are built on a distributed

architecture that provides a level of inherent redundancy and resiliency not found in

traditional 2 radio AP + controller solutions. The high-density radio implementation of

the Xirrus solution provides for a dramatic reduction in the need for physical devices -

51 Xirrus Arrays to 192 Cisco/Aruba’s APs in the first example described below. In the

simplest terms, this Xirrus advantage translates into lower capital expenditures (CapEx)

for hardware, device installation and network infrastructure upgrades and lower

operational expenditures (OpEx) for maintenance, support and power consumption.

To illustrate the Xirrus architectural benefits in a way that would be meaningful to

wireless LAN architects and implementers, Xirrus commissioned Tolly to develop a cost

analysis for three common wireless LAN deployment scenarios: 1) Enterprise, 2) Primary/

Secondary School District, and 3) Convention Center1.

The detailed bills of materials (BOM) used as the basis for this analysis are included in a

companion appendix document (Tolly document 211100APPENDIX).

Xirrus Wireless LAN Cost and Capacity Analysis #211100

© 2011 TOLLY ENTERPRISES, LLC PAGE 2 OF 17WWW.TOLLY.COM

1 The Cisco and Aruba system specifications were confirmed by VARs for those vendors.

Analysis Highlights:

The total cost - CapEx plus OpEx over a 5 year period - for implementing a Xirrus Wi-Fi solution per radio is less than both Aruba and Cisco in the 3 different use cases tested - enterprise, primary/secondary school district, and convention center

The Xirrus solution provides over 15% more deployed Wi-Fi capacity, and over 35% more maximum capacity, with an equal number of radios due to its flexibility in operating in the higher capacity 5GHz spectrum

The Xirrus solution requires significantly fewer devices deployed compared to competit ive solut ions, resulting in lower installation, cabling, switch infrastructure, p o w e r , a n d o n g o i n g management costs

In all three scenarios detailed in this paper, the Xirrus solution provided greater CapEx

and OpEx value than the alternative solutions even when compared to non-redundant

solutions from Aruba Networks and Cisco Systems.

The Xirrus solutions were compared with Cisco Systems solutions based on the Aironet

3502 and 1142 lines of access points and Aruba Networks solutions based on the AP-125

line of access points along with appropriate controllers and software to create

comparable solutions.

High Radio Density + Distributed Architecture = Lower Costs

Tolly analysts found that across all three deployment scenarios, the radio density

benefits of Xirrus translated into significant reductions in both CapEx and OpEx. All Cisco

Systems and Aruba Networks APs are limited to two dedicated radios - one each for the

2.4GHz and 5GHz bands. This contrasts with the Xirrus family of products that range

from 4 to 16 radios per Array. (Up to three radios on each Array can communicate on the

2.4GHz band and can be switched to the 5GHz band as required.) The 4 to 16 radios are

coupled with directional antennas that increase the range and ultimately allow the



Enterprise Primary/Secondary School District Conference Center

Price/Mbps of Xirrus Resilient Distributed Design versus Equal Radio Redundant and Non Redundant Deployments From

Cisco Systems and Aruba Networks(Lower numbers are better)

Xirrus:Resilient

Distributed Design

Cisco: Non Redundant

Controllers

Cisco: Redundant Controllers

Aruba:Non Redundant

Controllers

Aruba: Redundant Controllers

Source: Tolly, August 2011 Figure 1

$0

$2.00

$4.00

$6.00

4.54

3.80

5.30

4.46

2.19

3.66

3.10

4.82

3.75

2.30

3.93

3.29

4.76

4.00

2.38

Cos

t per

Mbp

s of

Ban

dwid

th (

US

$)

Array to replace a greater number of APs. Typically 1 Xirrus Array can displace 4

traditional APs.

As can be seen below, the deployment of low-density APs from Cisco/Aruba

dramatically increases the number of APs that need to be purchased, installed and

maintained when compared with the Xirrus solution. The small number of Arrays

required for each solution compared to Cisco/Aruba also places a much lower demand

on the existing wired network infrastructure to which the Arrays/APs must be

connected.

Because the Xirrus architecture is distributed and integrates the controller functionality

in the Array, there is no need for separate controller appliances that Cisco/Aruba require.

In fact, in order to build a Cisco/Aruba system that has an equivalent level of resiliency

as the Xirrus system, redundant controllers would be required for the Cisco/Aruba

solutions.

While there are myriad elements that constitute each deployment and there will be

variations for actual deployments, the cost-per-Mbps metric can provide a useful

“single-number” method for comparing the cost of solution for each megabit-per-

second of theoretical capacity.

In all three scenarios, the Xirrus solutions delivered capacity at the lowest cost of

approximately $2.00/Mbps. This compares favorably with the Cisco/Aruba solutions

even in non-redundant configurations as the Cisco solutions are in the $4.00/Mbps

range for non-redundant configurations and in the $5.00/Mbps range for redundant

configurations. The Aruba solutions average in the $3.50/Mbps range for non-redundant

configurations and $4.50/Mbps for redundant configurations. See Figure 1.

Enterprise Deployment Scenario

The enterprise scenario modeled a deployment of 1,000 users with 800 located at a

headquarters location and the remaining users spread among a single large branch

office and four small branch office locations. See Figures 2 and 3 for an illustration of the

HQ location. See Table 1 for a summary of each deployment scenario and a comparison

of Array/AP features relevant to this study.

Hardware costs for the Xirrus solution are estimated at $247,350 compared with

$338,504 for the Cisco solution with redundant controllers ($273,220 for non-

redundant). Hardware costs for the Aruba solution are estimated at $270,071 for the

redundant solution ($215,389 for non-redundant). See Table 3 for the scenario details2.

The Xirrus solution requires a mere 51 Arrays to provide the same coverage as 192 APs

each from Cisco/Aruba. Because nearly 4 times as many Cisco/Aruba APs are need as

Xirrus Arrays, the installation costs for Cisco/Aruba are considerably higher than those



2 The BOM for each scenario can be found in the report appendix document 211100 Appendix available at tolly.com.



Overview of Deployment Scenarios

Deployment Type Xirrus Solution Cisco Solution Aruba Solution

Enterprise:

No. of users: 1,000

1 Headquarters

1 Large Branch

4 Small Branches

45x XN8 Wi-Fi Arrays

6x XN4 Wi-Fi Arrays

51x 75W mid-span power injectors

Xirrus Management System

192x Aironet 3502i APs

192x mid-span power injectors

1x 5508 wireless controllers


NCS Management

192x AP-125 Thin APs


1x 6000 Mobility Controller with M3

Supervisor Card

1x 3200 Mobility Controller

4x 620 Mobility Controllers

Airwave Management

Primary / Secondary

School District:

20 schools, 10,000

students

250x XN8 and 100x XN4 Wi-Fi Arrays



1,200x Aironet 1142 APs

1,200x mid-span power injectors


NCS Management

1,200x AP125 Thin APs

1,200x mid-span power injectors




Airwave Management

Convention Center:

2,000 simultaneous

users.

1 million square foot

coverage

4x XN16, 8x XN12 and 8x XN8 Wi-Fi

Arrays




112x Aironet 3502i APs


1x 5508 wireless controller

NCS Management

112x AP-125 Thin APs


1x 6000 Mobility Controller with M3

Supervisor Card

Airwave Management

Partial AP Feature Comparison

Feeature Xirrus XN16 Xirrus XN12 Xirrus XN8 Xirrus XN4Cisco Aironet

1142Cisco Aironet

3502iAruba AP-125

802.11 Opeeration Modes a/b/g/n a/b/g/n a/b/g/n a/b/g/n a/b/g/n a/b/g/n a/b/g/n

Integrated Controller Yes Yes Yes Yes No No No

Number off Radios 16 12 8 4 2 2 2

Radios 2.4 GHz Only 0 0 0 0 1 1 1

per Wi-Fi 2.4 or 5 GHz 4 4 4 4 0 0 0

Band 5 GHz Only 12 8 4 0 1 1 1

PoE SuppoortYes (High

Power)

Yes (High

Power)

Yes (High

Power)

Yes (High

Power) Yes (802.3af) Yes (802.3af)

Yes (802.3af or

802.3at)

Threat Sensor (IDS/IPS) Yes (Full-time) Yes (Full-time) Yes (Full-time) Yes (Full-time)Yes (Dedicated

mode only)

Yes (Time-

sliced or

dedicated

mode only)

Yes (Time-

sliced or

dedicated

mode only)

Automatic RF Sensing Yes Yes Yes Yes Yes Yes Yes

Spectrum AAnalysis Yes (Full-time) Yes (Full-time) Yes (Full-time) Yes (Full-time) No

Yes (Part -time

or dedicated

mode only)

Yes (Part-time

or dedicated

mode only)

Maximum Wi-Fi Capacity 4.8 Gbps 3.6 Gbps 2.4 Gbps 1.2 Gbps 600 Mbps 600 Mbps 600 Mbps

Source: Tolly, August 2011 Table 1

Note: Threat sensor is also known as a wireless intrusion detection system or WIDS.

for Xirrus. Where Tolly analysts estimate infrastructure and installation to run $15,000 for

the Xirrus solution, the installation costs for the Cisco/Aruba solutions - each requiring

192 APs - is projected to be $54,4003. It should be noted that these installation costs do

not include any costs associated with installing or configuring the requisite Cisco/Aruba

wireless LAN controllers.

In total, including management software, the Xirrus solution CapEx is $273,900

compared to a range of $341,112 to $406,496 for Cisco and $281,035 to $335,718 for

Aruba. This translates to a 20% to 33% lower cost compared to Cisco and a 2% to 18%

lower cost for Aruba on CapEx alone.



3 See Methodology section for assumptions concerning labor rates and installation time.

Wireless LAN Design and Implementation Considerations

Topic Notes

Cabling Costs for APs/Controllers

The greater the number of APs and Wi-Fi controllers required to provide acceptable coverage, the greater

the cabling costs. In deployments like convention centers, casinos, etc. cabling costs could reach one

thousand dollars or more per run.

LAN Switch Port CostsEvery AP and controller needs to be connected to a LAN switch. As noted above, a system requiring a

large number of APs/controllers will require and equivalent number of LAN switch ports.

Installation Time/CostThe effort to install APs/controllers is considerable as each needs to be physically installed. Again, a

system requiring more APs/controllers will result in greater installation time and expense.

Power Consumption Lower power consumption results in direct OpEx savings that add up over the life-time of the product.

Maintenance/SupportHardware and software maintenance/support contracts form a major share of ongoing maintenance

costs.

Training Identify training requirements and factor in direct cost and time requirements.

Site Survey Costs A proper site survey is a prerequisite for a proper design. Factor in the survey cost.

Coverage GuaranteeTo make a system more attractive, a vendor can specify too-few APs resulting in coverage problems.

Require that your vendor guarantee coverage.

Wireless Security Monitoring

Security monitoring with threat sensor radios is important for Wi-Fi networks to maintain the security of

the network and ensure quality of experience to all users. Some products implement a dedicated threat

sensor on the AP, while others make APs perform threat sensing on a time-sliced basis, or create a

dedicated threat sensing network of APs overlaying the APs providing the primary access. Solutions that

do not offer integrated monitoring can require a significant CapEx investment to provide an overlay

security monitoring network.

Gigabit Ethernet/PoEIf the existing network aggregation layer switches are Fast Ethernet and/or non-PoE compliant, upgrade

costs to Gigabit Ethernet and PoE could be a significant CapEx and OpEx outlay.


Note: Topics in italics are factored in to the cost models in this report.

Furthermore, the Xirrus solution delivers

115.2 Gbps of theoretical system

bandwidth capacity compared to 85.3

Gbps for Cisco/Aruba. The Xirrus cost/

capacity benefit ranges from 39% to

100% versus the Cisco/Aruba solutions

Finally, the Xirrus solution allows users to

dedicate a single radio in an Array as a

threat sensor. Because Xirrus has higher

radio density, the company notes that it

can provide this functionality without a

negative impact on user experience.

The Cisco 3502 line and Aruba APs can

offer the same functionality, but

implement the security feature using

dedicated or shared/overlay threat

sensor radios. In dedicated mode, the

radios used as threat sensors are no

longer available for use for general

network traffic. In shared mode, a slice of

time is used to scan the network for

threats each second during which time

the AP is not available to carry user

traffic.

The other large cost associated with Wi-

Fi deployments is maintenance in the

form of support contracts, combined

with the cost of the continued power

usage of all devices. The Xirrus

deployment provides the lowest annual

OpEx of any solutions analyzed at

$11,098.

While Cisco/Aruba OpEx is similar for

non-redundant configurations, the OpEx

calculated for Cisco’s redundant solution

is $20,782 or almost double the non-

redundant OpEx of $11,237.

The OpEx for Aruba’s redundant solution

is $26,578 or over $10,000 more than the

$15,890 for the non-redundant Aruba

solution.



Enterprise Headquarters Deployment Xirrus XN8



Enterprise Headquarters Deployment Traditional AP




Enterprise Deployment - Summary of Projected Costs

Xirrus:

Resilient

Distributed

Design

Cisco:

Non-

Redundant

Controller

Cisco:

Redundant

Controller

Aruba:

Non-

Redundant

Controller

Aruba:

Redundant

Controller

Discount 25% 25% 25% 25% 25%

Number Of Arrays / APs 51 192 192 192 192Number Of Radios (2.4 & 5GHz) 384 384 384 384 384

CapExHardware & Software

Headquarters 40 XN8, ArrayOS,

PoE Injectors

160x 3502i, 1x

5508, PoE, Licenses

160x 3502i, 2x

5508, PoE, Licenses

160x AP-125, 1x 6000 (1xM3), PoE,

Licenses

160x AP-125, 1x 6000 (2xM3), PoE,

Licenses

Extended List Price $ 268,333 $ 299,110 $ 367,180 $ 234,370 $ 289,345

Large Branch 5 XN8, ArrayOS, PoE Injectors

20x 3502i, 1x 2500, PoE, Licenses

20x 3502i, 2x 2500, PoE, Licenses

20x AP-125, 1x 3200, PoE, Licenses

20x AP-125, 2x 3200, PoE, Licenses


Small Branches (Four Locations)6 XN4, ArrayOS,

PoE Injectors

12x 3502i, 4x 2500,

PoE, Licenses

12x 3502i, 8x 2500,

PoE , Licenses

12x AP-125, 4x 620,

PoE, Licenses

12x AP-125, 8x 620,

PoE, Licenses


Subtotal (With 25% discount) $ 247,350 $ 273,220 $ 338,504 $ 215,389 $ 270,071

Management

Management Software for all devices (With 25% discount) $ 11,250 $ 13,493 $ 13,493 $ 11,246 $ 11,246

Infrastructure & Installation

GigE Switch Ports @ $100 per port $ 5,100 $ 19,200 $ 19,200 $ 19,200 $ 19,200

Cat 5E Cable Runs @ 150 per run $ 7,650 $ 28,800 $ 28,800 $ 28,800 $ 28,800

Installation: 30min per Array, 20min per AP @ $100/hr $ 2,550 $ 6,400 $ 6,400 $ 6,400 $ 6,400

Subtotal $ 15,300 $ 54,400 $ 54,400 $ 54,400 $ 54,400

Total CapEx $ 273,900 $ 341,112 $ 406,396 $ 281,035 $ 335,718

Annual OpExx

Support

Headquarters List Price $ 7,825 $ 7,898 $ 15,796 $ 11,095 $ 18,790

Large Branch List Price $ 978 $ 720 $ 1,440 $ 1,470 $ 2,940

Small Branches (Four Locations)List Price $ 587 $ 800 $ 1,600 $ 1,280 $ 2,560

Subtotal $ 9,390 $ 9,418 $ 18,836 $ 13,845 $ 24,290EnergyAnnual Energy Cost (Max Rated Reduced by 33%) $ 1,708 $ 1,819 $ 1,946 $ 2,045 $ 2,288

Total Annual OpEx $ 11,098 $ 11,237 $ 20,782 $ 15,890 $ 26,578

Total Cost of Owneership

Total CapEx $ 273,900 $ 341,112 $ 406,396 $ 281,035 $ 335,718


Total Expense Over 5 Years $ 329,390 $ 397,300 $ 510,308 $ 360,485 $ 468,608

Xirrus Cost Savings Over 5 Year Lifespan N/A $67,909 $180,918 $31,095 $139,218

Capacityy, Energy, & EnvvironmentalTotal Energy Consumed Over 5 Year Lifespan (kwh) 85,400 90,973 97,323 102,250 114,400

Xirrus Energy Savings Over Competitor (kwh) N/A 5,573 11,923 16,850 29,000

Tons of CO2 Released Over 5 Year Lifespan 23.29 24.81 26.53 27.89 31.20

Xirrus CO2 Savings Over Competitor (Tons) N/A 1.52 3.24 4.60 7.91

Deployed Wi-Fi Bandwidth Capacity 100.3 Gbps 85.3 Gbps 85.3 Gbps 85.3 Gbps 85.3 Gbps

Maximum Wi-Fi Bandwidth Capacity of Solution 115.2 Gbps 85.3 Gbps 85.3 Gbps 85.3 Gbps 85.3 Gbps

Cost per Mbps of Wi-Fi Bandwidth $2.38 $4.00 $4.76 $3.29 $3.93

Xirrus Cost / Capacity Benefit Over Competitors N/A 68% 100% 39% 65%

Because of Cisco and Aruba

licensing requirements, users

wishing to deploy a redundant

configuration will need to pay

support for all of their APs twice

each year - once for the main

controller and once for the

redundant controller.

Primary/Secondary School

District Deployment Scenario

The school scenario modeled a

school district scenario consisting

of 10,000 students across twenty

schools - 3 large, 3 small and 14

medium-sized schools. See

Figures 4 and 5 for an illustration

of the medium-size school. See

Table 4 for a summary of each

scenario and a comparison of

Array/AP features relevant to this

study.

Hardware costs for the Xirrus

solution are estimated at $1.54M

compared with $2.16M for the

Cisco solution with redundant

controllers ($1.66M for non-

redundant). Hardware costs for

the Aruba solution are estimated

at $1.57M for the redundant

so lut ion ($1 .28M for non-

redundant). See Table 4 for the

scenario details.

As seen in the Enterpr ise

deployment, the Xirrus solution

requires far fewer Arrays - 350

Arrays to provide the same

coverage as 1,200 APs each from

Cisco/Aruba. Because almost 3.5

times as many Cisco/Aruba APs

are need as Xirrus Arrays, the

installation costs for Cisco/Aruba



Primary/Secondary School District Deployment with Traditional APs (Medium School)


Primary/Secondary School District Deployment with Xirrus Arrays (Medium School)





Primary / Secondary School District Deployment - Summary of Projected Costs

Xirrus:

Resilient

Distributed

Design

Cisco:

Non-

Redundant

Controller

Cisco :

Redundant

Controller

Aruba:

Non-

Redundant

Controller

Aruba :

Redundant

Controller

Discount 25% 25% 25% 25% 25%Number Of Arrays / APs 350 1200 1200 1200 1200

Number Of Radios (2.4 & 5GHz) 2400 2400 2400 2400 2400CapEx

Hardware & Software

3 Large Schools65 XN8, 26 XN4, ArrayOS, PoE

316x 1142N, 3x 5508, PoE, Licenses


316x AP-125, 3x 3600, PoE,

Licenses

316x AP-125, 6x 3600, PoE,

Licenses


14 Medium Schools170 XN8, 68 XN4,

ArrayOS, PoE

812x 1142N, 14x

5508, PoE, Licenses

812x 1142N, 28x

5508, PoE, Licenses

812x AP-125, 14x 3400, PoE,

Licenses

812x AP-125, 28x 3400, PoE,

Licenses

Extended List Price $ 1,395,156 $ 1,461,838 $ 1,994,748 $ 1,152,550 $ 1,420,020

3 Small Schools15 XN8, 6 XN4, ArrayOS, PoE



72x AP-125, 3x 3200, PoE,

Licenses

72x AP-125, 6x 3200, PoE,

Licenses


Subtotal (With 25% discount) $ 1,538,775 $ 1,597,211 $ 2,164,823 $ 1,275,833 $ 1,570,665

Management




Cat 5E Cable Runs @ $150 per run $ 52,500 $ 180,000 $ 180,000 $ 180,000 $ 180,000


Subtotal $ 105,000 $ 340,000 $ 340,000 $ 340,000 $ 340,000

Total CapEx $ 1,655,025 $ 2,002,454 $ 2,570,066 $ 1,654,825 $ 1,949,658

Annual OpExxSupport

3 Large SchoolsList Price $ 11,031 $ 14,557 $ 27,157 $ 15,099 $ 28,794

14 Medium SchoolsList Price $ 28,851 $ 48,334 $ 87,534 $ 44,562 $ 82,572

3 Small SchoolsList Price $ 2,546 $ 5,797 $ 9,637 $ 5,439 $ 9,474

Subtotal $ 42,428 $ 68,688 $ 124,328 $ 65,100 $ 120,840Energy

Annual Energy Cost (Max Rated Reduced by 33%) $ 10,858 $ 12,196 $ 13,546 $ 11,806 $ 12,343



Total CapEx $ 1,655,025 $ 2,002,454 $ 2,570,066 $ 1,654,825 $ 1,949,658


Total Expense Over 5 Years $ 1,921,455 $ 2,406,874 $ 3,259,436 $ 2,039,355 $ 2,615,573

Xirrus Cost Savings Over 5 Year Lifespan N/A $485,419 $1,337,981 $117,900 $694,118Capacityy, Energy, & Envvironmental

Total Energy Consumed Over 5 Year Lifespan (kwh) 2,121,400 3,434,400 6,216,400 3,255,000 6,042,000

Xirrus Energy Savings Over Competitor (kwh) N/A 3,434,252 6,216,252 3,254,852 6,041,852




Maximum Wi-Fi Bandwidth Capacity of Solution 720 Gbps 533.3 Gbps 533.3 Gbps 533.3 Gbps 533.3 Gbps



are considerably higher than those for Xirrus.

Where Tolly analysts estimate infrastructure and

installation to run $105,000 for the Xirrus solution,

the installation costs for the Cisco/Aruba solutions

is projected to be $340,000. It should be noted that

these installation costs do not include any costs

associated with installing or configuring the

requisite Cisco/Aruba wireless LAN controllers.

In total, including management software, the

Xirrus solution CapEx is $1.66M compared to a

range of $2.0M to $2.57M for Cisco and $1.65M to

$1.94M for Aruba.

This translates to a 17% to 35% lower cost

compared to Cisco and to 14% lower cost versus

the Aruba redundant solution on CapEx alone.

Furthermore, the Xirrus solution delivers 720 Gbps

of theoretical system bandwidth capacity

compared to 533.3 Gbps for Cisco/Aruba. The

Xirrus cost/capacity benefit ranges from 35% to

110% versus the Cisco/Aruba solutions

As in the Enterprise scenario, the Xirrus

deployment provides the lowest annual OpEx of all

solutions analyzed at $53,286.

For Cisco, the OpEx calculated for Cisco’s redundant

solution is $137,874 or 70% greater than the non-

redundant OpEx of of $80,884.

The OpEx for Aruba’s redundant solution is

$133,183 or 70% greater than the $76,906 for the

non-redundant Aruba solution.

Convention Center Deployment Scenario

Convention center deployments are typically

characterized by large user densities over large

open floor areas (exhibit space, lobbies) plus more

concentrated areas (classrooms, auditoriums).

The convention center scenario modeled an

environment where 2,000 simultaneous users

could be supported across a coverage area of 1

million square feet. See Figures 6 and 7 for an




Convention Center Deployment with Xirrus Arrays


Convention Center Deployment with Traditional APs




Convention Center Deployment - Summary of Projected Costs

Xirrus:

Resilient

Distributed

Design

Cisco:

Non-

Redundant

Controller

Cisco :

Redundant

Controller

Aruba:

Non-

Redundant

Controller

Aruba :

Redundant

Controller

Discount 25% 25% 25% 25% 25%

Number Of Arrays / APs 20 112 112 112 112

Number Of Radios (2.4 & 5GHz) 224 224 224 224 224

CapEx

Hardware & Software

Convention Center8 XN8, 8 XN12, 4

XN16, ArrayOS, PoE

112x 3502i, 1x

5508, PoE, Licenses

112x 3502i, 2x

5508, PoE, Licenses

112x AP-125, 1x 6000 (1xM3), PoE,

Licenses

112x AP-125, 1x 6000 (2xM3), PoE,

Licenses


Subtotal (With 25% discount) $ 134,250 $ 162,970 $ 204,644 $ 132,128 $ 168,949

Management




Cat 5E Cable Runs @ $300 per run $ 6,000 $ 33,600 $ 33,600 $ 33,600 $ 33,600


Subtotal $ 9,000 $ 48,533 $ 48,533 $ 48,533 $ 48,533

Total CapEx $ 147,000 $ 222,221 $ 263,894 $ 189,235 $ 226,056

Annual OpExx

Support

List Price $ 5,258 $ 6,332 $ 10,532 $ 10,090 $ 16,960

Subtotal $ 5,258 $ 6,332 $ 10,532 $ 10,090 $ 16,960

Energy

Annual Energy Cost (Max Rated Reduced by 33%) $ 845 $ 1,080 $ 1,147 $ 1,187 $ 1,322



Total CapEx $ 147,000 $ 222,221 $ 263,894 $ 189,235 $ 226,056


Total Expense Over 5 Years $ 177,515 $ 259,281 $ 322,289 $ 245,620 $ 317,466

Xirrus Cost Savings Over 5 Year Lifespan N/A $81,766 $144,774 $68,105 $139,951

Capacityy, Energy, & Envvironmental

Total Energy Consumed Over 5 Year Lifespan (kwh) 42,250 54,000 57,350 59,350 66,100

Xirrus Energy Savings Over Competitor (kwh) N/A 11,750 15,100 17,100 23,850




Maximum Wi-Fi Bandwidth Capacity of Solution 67.2 Gbps 49.8 Gbps 49.8 Gbps 49.8 Gbps 49.8 Gbps



illustration of a convention center deployment. See Table 5 for a summary of each

scenario and a comparison of Array/AP features relevant to this study.

Hardware costs for the Xirrus solution are estimated at $134,250 compared with

$204,644 for the Cisco solution with redundant controllers ($162,970 for non-

redundant). Hardware costs for the Aruba solution are estimated at $168,949 for the

redundant solution ($132,128 for non-redundant). See Table 4 for the scenario details.

As seen in the previous scenarios, the Xirrus solution requires far fewer Arrays - 20 Arrays

to provide the same coverage as 112 APs each from Cisco/Aruba. Because over 5.5 times

as many Cisco/Aruba APs are need as Xirrus Arrays, the installation costs for Cisco/Aruba

are considerably higher than those for Xirrus. Note, also, that analysts estimate a cost of

$300 per drop to account for union labor compared with $100 per drop in the other

scenarios.

Where Tolly analysts estimate infrastructure and installation to run $9,000 for the Xirrus

solution, the installation costs for the Cisco/Aruba solutions is projected to be $48,533. It

should be noted that these installation costs do not include any costs associated with

installing or configuring the requisite Cisco/Aruba wireless LAN controllers.

In total, including management software, the Xirrus solution CapEx is $147,000

compared to a range of $222,221 to $263,894 for Cisco and $189,235 to $226,056 for

Aruba.

This translates to a 34% to 44% lower cost compared to Cisco and 22% to 35% lower

cost versus the Aruba redundant solution on CapEx alone.

Furthermore, the Xirrus solution delivers 67.2 Gbps of theoretical system bandwidth

capacity compared to 49.8 Gbps for Cisco/Aruba. The Xirrus cost/capacity benefit ranges

from 74% to 142% versus the Cisco/Aruba solutions

As in the Enterprise scenario, the Xirrus deployment provides the lowest annual OpEx of

all solutions analyzed at $6,103. For Cisco, the OpEx calculated for Cisco’s redundant

solution is $11,679 or 84% greater than the non-redundant OpEx of $6,332.

The OpEx for Aruba’s redundant solution is $18,282 or 62% greater than the $11,277 for

the non-redundant Aruba solution.

Additional Wireless LAN Design Challenges

In addition to the obvious requirements cited in deployment models, there are a range

of ancillary concerns that will likely vary from customer to customer and installation to

installation but can, nevertheless, have a significant impact on cost.

While outside the scope of the model, Tolly analysts have outlined a few of these areas

in Table 2.



Methodology

Tolly analysts modeled three wireless LAN deployment scenarios. This project did not

involve any testing. All raw data was derived from vendor data sheets, price lists, and

theoretical radio capacity.

Xirrus provided the design for its solutions. The solutions used for Cisco Systems and

Aruba Networks were reviewed and confirmed by a value-added reseller that sells and

installs solutions from both vendors. To provide a basis for comparison, designers

developed solutions where all three vendors would provide the same number of radios

per-location for each solution.

As noted earlier, the Xirrus solution integrates the controller function in its Arrays where

both Cisco Systems and Aruba Networks implement the wireless LAN controller function

in a standalone appliance. In order to provide the reader with an appropriate basis for

comparison, both non-redundant and redundant configurations were developed for the

non-Xirrus solutions. The redundant controller configurations for Cisco/Aruba are

effectively equivalent to the Xirrus solution since a single controller presents a single

point of failure in the network for an entire location. The Xirrus solution does not have a

single point of failure.

Analysts built the analysis around costs that would likely be present and relatively

consistent across implementations by multiple customers. Analysts also note that there

can be significant ancillary costs that could vary dramatically from implementation to

implementation and, thus, were not included in the calculations. (Table 2 includes

references to some of the ancillary costs.)

Analysts also derived a cost-per-Mbps metric to provide a method for comparing the

system cost for an equivalent bandwidth capacity. These calculations are based on the

maximum data rate (instantaneous throughput) of each radio (described below) and

therefore do not reflect actual system throughput. However these numbers provide a

baseline for capacity comparisons between the systems under review.

The following sections provide details on the approach used in evaluating each area of

the cost model.

Hardware, Licensing, and Management

To standardize the evaluation as much as possible, engineers scoped out all scenarios

with the same number of radios for each vendor, broken up by each location. Each

scenario was then provided to third-party VARs for Cisco and Aruba, who confirmed the

quantities and US list prices for devices, applicable licensing, as well as management

software necessary for the deployment.

From this list pricing, Tolly analysts then built out extended list pricing for each

applicable location in each scenario. While vendor pricing and discounting will vary by



vendor and situation, the VAR confirmed that some discounting from list price would

normally occur at the product volume levels used in the analysis scenarios.

Analysts applied an arbitrary, but common discount, of 25% to the list prices of

hardware components of each wireless LAN solution.

Support

Support costs were provided by a VAR on an annual basis. The annual cost was

extrapolated to 5 years assuming annual renewal and no increase to the first-year

support costs.

Access Point Installation

Each AP will require a wired connection to a LAN switch port. Analysts assumed a

Gigabit Ethernet switch would be used and assumed a port cost of $100 per port.

The Cisco and Aruba APs can be powered by 802.3af switches. However many customers

do not already have PoE switches in place and opt to buy injectors from the

manufacturer for powering the APs. In addition, 2 radio 802.11n APs operate near the

maximum power limit of 802.3af and some compromise functionality when

approaching this limit. Thus higher power injectors are offered by the manufacturers.

The Cisco injector is 18W for example. The higher radio density of the Xirrus solution

requires power in excess of that available via an 802.3af PoE switch and thus uses power

injectors. Power injectors are assumed for all products in this analysis but may be

factored out if users have PoE switch ports in place and available.

Costs for running the Ethernet cable between the AP/Array and the wiring closet will

vary greatly by geography and environment. For the purposes of this analysis, a cost of

$100 per drop was used for the enterprise and school district scenarios. Certain

scenarios, such as the conference/convention center scenario found in this paper, will

typically require that more costly union labor will be used to run the drops. This paper

assumes that cable drops will cost $300 per drop in the convention center deployment.

The physical installation of the AP/Array is fairly simple. The analysis assumes 20

minutes for each AP and 30 minutes for each Array and a labor rate of $100/hr is used.

It should be noted that the installation time does not include any software/

management installation/configuration that may have to be carried out prior to use.

The costs noted here do not include any costs associated with the installation of the

wireless LAN controllers that are required in the Cisco/Aruba architectures.

Wi-Fi Bandwidth: Theoretical Capacity

As noted earlier, each solution was built with an equivalent number of radios per

location.



In order to understand the analysis details, it is necessary that the reader understand the

fundamental radio difference between Xirrus and Cisco/Aruba. All vendors provide both

older 2.4GHz band radios in their AP/Arrays for backward compatibility with legacy gear

along with current 5GHz band radios. Today’s clients support either 2.4GHz-only or dual-

band 2.4GHz/5GHz making the 2.4GHz the “least common denominator” though

standards work now focuses on the 5GHz band for future development.

Each Cisco/Aruba APs provides two radios - one for each band. In situations where there

are no devices requiring legacy 2.4GHz radios, those radios cannot be used to provide

additional 5GHz capacity.

Each Xirrus Array, depending upon the model selection, contains up to 16 radios of

which up to 3 can run on the 2.4GHz band4 . In situations where 2.4GHz legacy

connectivity is not needed or is minimal, any or all of these 3 radios can be reconfigured

via the management software to run as 5GHz radios thus increasing the bandwidth for

that band and the overall system. It is this difference that explains the difference in the

“Deployed Wi-Fi Bandwidth Capacity” line item in Tables 3-5.

For the calculations made throughout this document, each 2.4GHz radio is rated at a

theoretical maximum throughput of 144.4 Mbps, while each 5GHz radio at 300 Mbps.

This reflects use of 20MHz channels in 2.4GHz and 40MHz channels (bonded) in 5GHz.

Since only 3 non-overlapping channels are available in the 2.4GHz spectrum, it is

impractical in real deployments to run 40MHz channels in 2.4GHz. It is also important to

note that in actual use, the actual throughput one can expect out of each radio band

will be less than the maximums due to overhead in the protocol.

Power Consumption/Carbon Footprint

To calculate the power consumption of each vendor’s configuration, analysts utilized the

vendor-published maximum power ratings for each component, reduced by 33%5 to

reflect likely operating usage, extrapolating the data to a 24x7 yearly estimate.

The price per kilowatt-hour of energy is taken from the U.S Energy Information

Administration’s yearly report on costs - http://www.eia.gov/cneaf/electricity/epm/

table5_6_a.html - with $0.10 per kWh being the average commercial cost for

2010-2011. Aside for the monetary impact of power usage, engineers also evaluated

each solutions carbon footprint via energy consumption, utilizing an online tool to

gather data. http://chuck-wright.com/calculators/carbon.html



4 According to Xirrus, four radios can run on the 2.4GHz band, three at any one time.

5 Previous Tolly testing has shown that the power requirements that vendors list on their data sheets typically overstate the actual consumption. Thus, to model an actual usage scenario, analysts applied a reduction to all stated values.



211100 Yfobljt4 kt jft 05Aug2011 verT

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Documents

Tolly Report #211100 August 2011 Commissioned by Xirrus…tolly.com/ts/2011/Xirrus/TCO/Tolly211100XirrusWLANCostandCapacity... · August 2011 Commissioned by Xirrus, Inc. Executive