xendesktop to branch offices_v2

7/21/2019 XenDesktop to Branch Offices_v2

http://slidepdf.com/reader/full/xendesktop-to-branch-officesv2 1/30

WHITE PAPER | Citrix XenDesktop and Branch Repeater

www.citrix.com

Performance Assessment and

Bandwidth Analysis for Delivering

XenDesktop to Branch Offices

Citrix XenDesktop and Branch RepeaterPerformance Analysis



Contents

Executive Overview .......................................................................................................................................... 3

Product Overview .............................................................................................................................................. 5

Test Environment .............................................................................................................................................. 7

Test Methodology .............................................................................................................................................. 9

Performance Results and Analysis ................................................................................................................ 12

Conclusion ........................................................................................................................................................ 23

Appendix A - Hardware and Software Configurations .............................................................................. 25

Appendix B - Citrix XenDesktop Configurations ...................................................................................... 26

Appendix C – Citrix Branch Repeater Configurations .............................................................................. 27

Appendix D – Login VSI Pro Configurations ............................................................................................ 27

Appendix E – HDX MediaStream Active Directory GPOs ..................................................................... 28

Appendix F - References ................................................................................................................................ 28



Executive Overview

Desktop virtualization is rapidly gaining momentum in the IT industry. The desire to centralize and

secure desktops, applications, and corporate data is a driving factor behind this trend. To make the

transition to a virtual desktop platform CIOs and administrators alike must ensure that all users have

a positive experience with the virtual desktop, even if they work in remote branch offices away from

the corporate datacenter. This whitepaper details the network bandwidth requirements per user for

a variety of use cases and provides the IT professional with critical data to plan the delivery of Citrix

virtual desktops across a WAN.

To provide users with a positive virtual desktop experience, IT professionals must ensure an

acceptable level of desktop performance can be provided to both corporate users as well as the

branch office users. The purpose of this paper is to provide the network administrator with

guidance for determining the amount of available bandwidth required for a Citrix XenDesktop

solution based on popular use cases. This paper details how the introduction of Citrix Branch

Repeater can provide significant bandwidth savings and performance improvements for branchoffice users and can in some cases negate the need for a costly network upgrade.

This unique partnership of combining Citrix XenDesktop with Branch Repeater is the only solution

on the market where the ability to compress native XenDesktop traffic is transitioned to a WAN

optimization solution, Citrix Branch Repeater, for optimal virtual desktop performance. The

adaptive orchestration where XenDesktop becomes Branch Repeater-aware provides significant

savings in the overall bandwidth requirements for XenDesktop as shown throughout this report.

The Citrix Consulting Solutions team conducted all the testing represented in this paper within the

Consulting lab environment at Citrix headquarters. All tests were based on the widely acceptedLoginVSI methodology and focused on common workflows such as standard MS Office tasks,

internet browsing, printing, and video.

Table 1 represents a high level overview of the bandwidth requirements for standard virtual desktop

workflows as represented in this document. The Branch Repeater numbers displayed in the table

represent a warm run (the test data passed through the Branch Repeater prior to testing). When data

first passes through Branch Repeater, compression algorithms are utilized to optimize TCP traffic

and cache the data stream. During the second request for the same data, Branch Repeater utilizes a

tokenizing engine to serve recognized data streams from local cache rather than pulling the same

data stream across the WAN. Therefore, the greatest bandwidth savings is recognized in all data

transfers after the first pass as shown in the following table.



Workflow Avg UserLoad

Environment Avg BandwidthConsumed

Office 20Native XenDesktop 43 kbps

XenDesktop & Branch Repeater 31 kbps

Internet Browsing 10-12Native XenDesktop 85 kbps

XenDesktop & Branch Repeater 38 kbpsPrinting 1 (5MB MS Word & PDF)

1Native XenDesktop 553-593 kbps

XenDesktop & Branch Repeater 155-180 kbpsFlash Video

(server-rendered)5

Native XenDesktop 174 kbpsXenDesktop & Branch Repeater 128 kbps

Standard WMV Video(client-rendered)

4Native XenDesktop 464 kbps

XenDesktop & Branch Repeater 148 kbpsHigh Definition WMV Video 2

(client-rendered)1-2

Native XenDesktop 1812 kbpsXenDesktop & Branch Repeater 206 kbps

Table 1: Average Bandwidth per Session

The Citrix Branch Repeater plays a critical role in optimizing an existing WAN connection and

improving the overall virtual desktop user experience in the branch office. The following key

findings from this report emphasize the strategic cost savings and performance improvement a

Branch Repeater solution can provide for any branch office XenDesktop deployment.

Citrix Branch Repeater can reduce the overall average bandwidth consumed per session by

up to 89%.

Citrix Branch Repeater can reduce the amount of time it takes for a XenDesktop session to

launch on a congested WAN connection by up to 40%.

Citrix Branch Repeater can double the number of users able to execute similar virtual

desktop activities on the same congested WAN connection.

Citrix Branch Repeater can reduce the amount of time it takes for the print request to spool

from the virtual desktop to the branch office print server by up to 60%.

1 To assess the maximum amount of bandwidth consumed for a single print job only one document was printed

per test on an uncongested WAN to provide the most conservative guidance. Additional XenDesktop policies and

Branch Repeater priority queuing can be implemented to optimize bandwidth availability during print jobs.2 The WAN parameters for the HD video were increased to 10mbps given that the data rate of the High Definition

video was 6.5 mbps. Only 1 user was evaluated on the 10mbps for native XenDesktop, but 2 users were evaluated

for XenDesktop with Branch Repeater.



Product Overview

Citrix XenDesktop

Citrix XenDesktop is a desktop virtualization solution that delivers Windows desktops as an on-

demand service to any user, anywhere. With FlexCast™ delivery technology, XenDesktop can

quickly and securely deliver individual applications or complete desktops to the entire enterprise,

whether they are task workers, knowledge workers or mobile workers. Users now have the flexibility

to access their desktop on any device, anytime, with a high-definition user experience. With

XenDesktop, IT can manage single instances of each OS, application and user profile and

dynamically assemble them to increase business agility and greatly simplify desktop management.

XenDesktop’s open architecture enables customers to easily adopt desktop virtualization using any

hypervisor, storage or management infrastructure.

Citrix Branch Repeater

Citrix Branch Repeater is a branch optimization solution that accelerates and simplifies branch

infrastructure. Branch Repeater solutions reduce IT costs and increase user productivity by

simplifying branch startup and management, and providing users the best access experience.

The Branch Repeater products achieve WAN optimization by combining a variety of technologies:

TCP Optimization: Branch Repeater is a symmetric solution, where a Branch Repeater is

located at each end of the WAN connection (in the datacenter and in the branch office)

recognize each other’s presence and employ RFC compliant TCP optimization techniques

that ensure optimal utilization of the network bandwidth.

Traffic Prioritization (QoS): Administrators can classify network bandwidth based on TCP

port numbers and IP ranges to prioritize the delivery of TCP segments based on the

classification. Furthermore, Branch Repeater recognizes the priorities of the various ICA

virtual channels and can ensure preferential treatment of real-time critical data such as audio.

Compression: Branch Repeater can detect repeating patterns in the transmitted data and

utilize very small tokens across the WAN to identify such repeating data patterns and serve

the data to the user out of the appliance memory; therefore, restricting the amount of data

required to traverse the WAN and improving user experience.

Protocol Optimization: Branch Repeater can optimize a variety of common application

protocols. Citrix XenDesktop leverages the ICA protocol, which employs a variety of

optimization and security features natively. In order to apply compression, a WAN optimizer

must be able to decrypt the ICA workload, identify repeating patterns within the ICA virtual

channels, apply the optimization, and re-encrypt the data stream. This is why Citrix Branch

Repeater is the only WAN optimization product capable of directly optimizing the ICA

payloads on the protocol level.



This paper focuses on the virtual desktop acceleration gained from the joint deployment of Citrix

Repeater in the datacenter and Citrix Branch Repeater in the remote branch office.

Citrix High Definition User Experience

With the release of Citrix XenDesktop 4, Citrix committed to providing the best high definition userexperience through the introduction of HDX technology. Citrix HDX technology builds on

existing Citrix user experience innovations from the datacenter to the device, adding enhancements

for multimedia, voice, video and 3D graphics. Citrix HDX is comprised the following categories:

HDX Broadcast – Ensures high-performance of virtual desktops and applications over any

network, including high-latency and low-bandwidth environments.

HDX WAN Optimization – Optimizes performance by utilizing Citix Branch Repeater to

cache bandwidth intensive data and graphics and deliver them from the most efficient

location.

HDX MediaStream – Accelerates multimedia performance through compression or, when

possible, redirection and client-side rendering.

HDX RealTime – Enhances real-time voice and video using advanced encoding and

streaming to ensure a no compromise end-user experience.

HDX 3D – Optimizes the performance of everything from graphics-intensive 2D

environments to advanced 3D geospatial applications using software and hardware based

rendering in the datacenter and on the device.

HDX Plug-n-Play – Enables simple connectivity for all local devices in a virtualized

environment, including USB, multi-monitor, printers and peripherals.

Citrix XenServer

Citrix XenServer is open, powerful server virtualization that radically reduces datacenter costs by

transforming static and complex datacenter environments into more dynamic, easy-to-manage server

workload delivery centers. Based on the open source Xen® hypervisor, XenServer delivers a secure

and mature server virtualization platform with near bare-metal performance.

Login VSI 2.1 Pro (Benchmarking Tool)

Login VSI 2.1 is a benchmarking tool specifically designed for SBC and VDI environments. VSI

loads the system with simulated user workload, and focuses on how much user load can be

generated within the system before performance degrades. VSI is a completely platform and

protocol independent tool. The VSI implementation and configuration is very simple and provides

engineers and administrators with a turn-key benchmark solution that allows testers to gather

metrics in days versus weeks. The tool is available in two versions. The free version is configured

with a standard user workflow that executes a combination of Microsoft Office, Internet Explorer



and printing tasks. The VSI Pro (paid version) provides testers the ability to generate workloads that

vary in intensity as well as the ability to execute custom workflows.

Login Consultants was the first company worldwide to be appointed as a Citrix Managed

Consultancy Provider. The strategic relationship between Citrix and Login Consultants has

developed XenDesktop testing standards that are proven and repeatable in any customerenvironment.

Test Environment

The Citrix Consulting Solutions team is committed to architecting and implementing real-world test

environments based on prior Citrix Consulting customer engagements. The following test

environment was constructed within the Consulting Solutions lab in Fort Lauderdale, Florida to

emulate a branch office scenario where end users are connecting to their virtual desktop over a

dedicated WAN link. The test environment consisted of a datacenter environment with Citrix

Repeater and a remote branch office environment with Citrix Branch Repeater connected by asimulated WAN. All XenDesktop, infrastructure, and branch office machines were virtualized using

Citrix XenServer.

Branch Office Datacenter

TE CHNOLOGI E S

M GM T L AN A L AN BCONSOLE

LINKTROPY

MINI

P O W E R S TA TU S

Print Server

Login VSI

File Share

Citrix XenServer

Login VSI Pro

Launcher

Login VSI Pro

Launcher

Login VSI Pro

Launcher

Virtual Desktops

Desktop Pool

Citrix XenServer

Desktop Pool

Citrix XenServer

Desktop Pool

Citrix XenServer

XenDesktop Environment

Delivery Controller

with Web Interface

Citrix Provisioning

Server

Citrix XenServer

Citrix Branch Repeater

Citrix Repeater

T1, 80ms Latency,

1% Packet Loss

Switch

Infrastructure

SQL Server

Active Directory

Citrix License

Server

Citrix

XenServer

Figure 1: Performance Assessment and Bandwidth Analysis Environment Architecture

The Citrix Consulting Solutions team leveraged Login VSI 2.0 Pro to create a standard method for

launching simultaneous virtual desktops through XenDesktop and a standard process for executing



automated end user workflows that incorporated applications such as Microsoft Office 2007 and

Internet Explorer 7 web browsing. Although the number of users and workflows varied, the

following steps provide a high level overview of the test execution process utilizing Login VSI 2.0

Pro:

Login VSI 2.0 Pro supports multiple simultaneous launchers through a master and slaveconfiguration. To execute a test, the Login VSI 2.0 Pro console on the master launcher is

configured with desktop connection information and a UNC path to the Login VSI share.

The Login VSI share must be on a file server that is accessible to both the launcher and the

virtual desktop executing the end user workflow.

The Login VSI share contains four critical files: VSILauncher.ini, VSITarget.ini,

LoginVSI.csv and LoginVSI.lic. The VSILauncher.ini file provides criteria regarding

connection information for accessing the Delivery Controller and launcher information such

as the list of additional launchers acting as slaves. The VSITarget.ini file is configurable in

the Pro version only to support light, medium, heavy or custom workflows. TheLoginVSI.csv file contains a list of unique usernames and passwords. The LoginVSI.lic

license file is necessary for the Pro version of the tool.

To execute a test, the ‘custom connection’ method is leveraged and a custom Python script

which emulates Internet Explorer browser sessions is used to launch multiple Web Interface

sessions.

The Python script is also leveraged to automatically enter multiple test user credentials on

each Web Interface session launched. These credentials are stored in the specified

LoginVSI.csv file.

Each Launcher had the Citrix Online Plug-in installed locally prior to test execution.

After the user was authenticated, the virtual desktop was automatically launched. The Login

VSI Launcher completed the process of launching desktop connections at this point.

The standard vDisk used for each virtual desktop was preconfigured with Microsoft Office

2007, RealTime Player, Windows Media Player and the Login VSI target deployment

software. Users were granted administrative privileges (as part of the Login VSI installation)

and all the workflow scripts were tested to ensure that all pop-up warnings were removed.

The Login VSI component on the virtual desktop referenced the VSITarget.ini file on the

VSI share. The VSITarget.ini file provided the component with instructions regarding the

user workflow.

The user workflow was embedded within the local desktop. All the keystrokes and mouse

clicks that are executed during the workflow are scripted within the virtual desktop;

therefore, there are no keystrokes or mouse clicks from the launcher in the branch office

traversing the WAN to communicate with the XenDesktop virtual desktop.



To execute the Office workflow, the user load was incremented in user counts of five for each test

cycle. The launcher was configured with a 30-second interval between each user launch. During

each test cycle, a single virtual desktop was monitored by the Consulting team to determine the

overall performance and responsiveness of the environment. This subjective assessment was made

by evaluating the responsiveness to typing, mouse clicks, and screen refreshes during each test cycle.

Several metrics were measured in addition to the overall user experience. The average bandwidth

consumed for the workflow was evaluated with and without Branch Repeater. In order to have all

the necessary users online at the same time to gather these metrics, the workflow would loop

continuously to allow the WAN emulator to record all active sessions during the same 10-minute

time interval given that there was a 30-second window between user launches. For example, to

assess 10 users in the environment the overall workflow would execute for 15 minutes to allow all

10 users to be active for 10 minutes to get a true average of bandwidth consumed. Additional

metrics such as XenDesktop launch time and Branch Repeater compression ratios were also

gathered for this workflow. It should be noted that the Branch Repeater numbers represented in

this testing reflect a warm run. A warm run is when the Branch Repeater has executed the Office workflow prior to the test cycle starting. With a warm run not all documents are seen prior to the

start of the workflow since the content varies from user to user.

Internet Explorer Workflow

The Consulting team developed a customized Internet Explorer workflow that accesses the

following websites: Citrix.com, Yahoo Finance, MSN, Gap.com, Amazon.com, Google Maps and

CNN. The customized workflow is over 11 minutes in duration. The Login VSI launcher was used

in conjunction with the customized workflow to bring users online in the same 30-second launch

interval used by the Office workflow scenario. Given that the workflow was only 11 minutes induration, the workflow continued to loop for each user to allow all users to be active for a 10-

minute window for measurements purposes. It should be mentioned that the websites specified in

the Internet Explorer workflow did include stock tickers and rotating ads, but the overall content

was similar in nature for every user added to the environment.

The execution of this workflow was comparable in design to the Office workflow, so only the

metrics specific to the Internet Explorer component of these workflows were collected. The overall

user experience was monitored in the same fashion as the Office workflow. A single virtual desktop

was monitored by the Consulting team to determine the overall performance and responsiveness of

the environment. This subjective assessment was made by evaluating the responsiveness to typing,

mouse clicks, and screen refreshes during each test cycle. The additional metrics gathered specific to

the Internet Explorer workflow included average bandwidth consumed and Branch Repeater

compression ratios. It should be noted that the Branch Repeater numbers represented in the

Internet Explorer workflow reflect a warm run.



Printing Workflow

Unlike the previous two workflows where the user continuously interacts with the desktop, a print

job is a single request from the virtual desktop to the printer. To assess the printing performance

for a variety of applications, a single user printed a 5MB Microsoft Word document and a 5MB PDF

file from within the virtual XenDesktop environment. The print server was located in the branchoffice which required the virtual desktop to spool the print request across the WAN. Citrix

XenDesktop does support the same printer policies that Citrix XenApp provides. By default, Citrix

XenDesktop polices are configured to set print spool requests as a low priority. For more

information regarding the XenDesktop policies used in this testing, please reference the Appendix A

of this document

For the Printing workflows, key metrics such as print spooling execution time, total bandwidth

consumed, and Branch Repeater compression ratios were gathered. It should be noted that the

Branch Repeater numbers represented in the printing workflow reflect a warm run.

Video Workflow

One of the strategic differences with XenDesktop versus competitive products is the HDX

technologies. When possible, HDX MediaStream leverages the processing power of the endpoint

device to render multimedia content. The video workflow assessed the performance of Windows

video utilizing the HDX MediaStream for Windows technology and Flash video utilizing standard

server-side video rendering.

HDX MediaStream for Windows

HDX MediaStream with Windows is a very powerful technology for a branch office virtual desktopdeployment. HDX MediaStream leverages the processing power of the branch office end-user

device to render the multimedia content. This allows the video stream to be sent to the branch

office in its native format, which typically requires much less bandwidth than rendering the video

within the virtual desktop, and sending all the individual frames across the WAN. For the purpose

of the testing in this paper, the process of obtaining the Windows Media content and rendering the

Windows Media content was divided between the virtual desktop running in the datacenter and the

end user device running in the branch office. The virtual desktop was responsible for fetching the

content from a file server in the datacenter that could only be accessed by the virtual desktop. The

virtual desktop fetched the WMV file from the file server and sent the content to the branch office

device in its native format. Once the branch office device received the content, the device utilizedits local Windows Media Player to render the video content; therefore, the video appears in the

virtual desktop with the same quality as rendering the video on the local device. Windows Media

Player was used to render the videos in this testing, but other media players based on DirectShow,

DMO or Media Foundation could also be used

In this test scenario, the server-side fetching and client-side rendering of two Windows Media

Videos were monitored. The first WMV file was a 5MB video, six minutes in duration with a data

rate of 70kbps, frame rate of 15 frames/second, and a 320x252 display. This 5MB video was



considered to be a standard video. The second video was labeled as a high definition (HD) video.

The HD video was the robotica.wmv file downloadable from the Microsoft WMV HD Conent

Showcase website. The HD video was a 16MB video, twenty-one seconds in duration with a data

rate of 6500kbps, frame rate of 23 frames/second, and a 1280x720 display.

For each video test scenario the video duration was a key component in evaluating the overallbandwidth for one to four users. In this scenario the video was executed concurrently across all

sessions without a 30-second launch interval as documented for the other workflows. The overall

user experience was evaluated based on the screen refreshes and overall video appearance. Other

key metrics included the total bandwidth consumed and the time duration for the data transfer. It

should be noted that the Branch Repeater numbers represented in the HDX MediaStream workflow

reflect a warm run.

Flash Video

When Flash video is viewed across the WAN, XenDesktop utilizes server-side fetching and server-

side rendering for the Flash video. With server-side fetching and server-side rendering, the Flash

video is rendered within the virtual desktop in the datacenter and the screen updates are sent across

the WAN connection.

For each test scenario, the Flash video was a 39MB flash video that was forty-one minutes, with a

data rate of 66.5kbps, frame rate of 9.9 frames/second, and a 320x240 display. The Shockwave

Flash video player was installed on the virtual desktop. The test scenarios included both a single –

user and a five-user test. The five-user test leveraged the VSI launcher where users had a 30-second

interval between session launches. The video ran for fifteen minutes to gather metrics for a ten-

minute average after all five users were actively watching the video. For this testing the overall user

experience was evaluated based on the screen refreshes and overall video appearance. Other keymetrics included the average bandwidth consumed. It should also be mentioned that the Branch

Repeater numbers represented in this testing reflect a warm run.

Performance Results and Analysis

Microsoft Office 2007 Workflows

Microsoft Office is the most frequently virtualized application utilizing Citrix technology. Figure 2

shows the average bandwidth consumed per user across the WAN as users performing Office

workflow were added to the environment and Figure 3 shows total average bandwidth consumedfor all users across the WAN.



Figure 2: Office Workflow-Average Bandwidth Consumed per User

Average Bandwidth consumed per User

XenDesktop uses the ICA protocol to render the virtual desktop on the end user device. The ICA

protocol is a highly optimized protocol by design. The ICA protocol will consume as much

available bandwidth as possible on a given link as noted by the higher bandwidth consumed during

low user load. When the amount of available bandwidth is restricted, the ICA protocol performs

well until the bandwidth restriction becomes too severe and user performance is degraded. This

aspect of the protocol made it important to also monitor user performance of the virtual desktopexecuting the Office workflow.

In the Average Bandwidth Consumed per User graph, the average bandwidth consumed line flattens

as the number of users continues to increase. The objective of this testing was not to determine the

minimum amount of bandwidth required, instead the objective was to identify the average amount

of bandwidth required to provide a user experience parallel to that of the local desktop. Figure 2

shows that the average bandwidth consumed per user required for the Office workflow for native

XenDesktop is effectively 43 kbps.

As part of the improvements in XenDesktop 4 and Branch Repeater 5, Branch Repeater can nowaccelerate the delivery of desktops by letting XenDesktop detect when Branch Repeaters are active

in the environment. Branch Repeater will recognize and parse the incoming ICA stream and take

part in the initial connection negotiations. Once the Citrix Online Plug-in and Delivery Controller

are aware of the Branch Repeaters, they will disable their native ICA compressors and hand-off the

compression to the Branch Repeaters.

0.00

10.00

20.00

30.00

40.00

50.00

60.00

0 5 10 15 20 25

A v g B a n d w i d t h C o n s u

m e d

p e r U s e r ( k b p s )

Users

Office Workflow

XenDesktop Average Bandwidth per User (Native)

XenDesktop Average Bandwidth per User (with Branch Repeater)



When the Branch Repeater was introduced into the environment, the average bandwidth per user

required for the Office workflow was reduced by 28% to 31 kbps while maintaining an excellent

overall user experience.

Figure 3: Office Workflow-Bandwidth Consumed for All Users

Bandwidth Consumed for All Users

One of the key benefits of introducing a Branch Repeater into any branch office scenario is the

ability to add more users to the existing environment without upgrading the WAN connection. When reviewing the total bandwidth consumed for all users, it can be derived that total bandwidth

consumed for 20 users was approximately 861 kbps for native XenDesktop and 622 kbps with

Branch Repeater. Given that a Branch Repeater user consumes an average of 31 kbps, then 7.7

additional users could be added to the environment to reach the same level of WAN utilization

shown without a Branch Repeater; therefore, approximately 40% more users can be added to a

XenDesktop Office workflow environment with a Branch Repeater solution in place.

0

100

200

300

400

500

600

700

800

900

1000

0 5 10 15 20 25

A v g B

a n d w i d t h C o n s u m e d ( k b p s )

Users

Office Workflow

XenDesktop Average Bandwidth (Native)

XenDesktop Average Bandwidth (with Branch Repeater)



Figure 4: Office Workflow-XenDesktop Launch Time

XenDesktop Launch Time

There is an inherent amount of time between the user entering their credentials into Web Interface

and the appearance of the virtual desktop display on the user’s screen. During this period, the

following actions take place:

Web Interface passes the validated credentials to the Delivery Controller XML Service

The XML Service authenticates the user against Active Directory

The XML Service then determines which virtual desktops are available to that user

The available desktop information is sent to Web Interface

Web Interface presents the desktop information to the user device

Web Interface creates an ICA file for user device

The Citrix Online Plug-in on the user device establishes the ICA connection over the WAN

to the desktop

In this test environment, the average XenDesktop launch time took approximately 6 seconds(Figure 4 displays the logon times as collected during the testing cycle). When WAN traffic

consumed more than 60% of the overall available bandwidth, the launch time increased to

approximately 10 seconds. When a Citrix Branch Repeater is introduced into the congested

environment, the launch time of the XenDesktop session returned to the original 6 seconds,

providing up to 40% XenDesktop Session Launch time improvements.

0 5 10 15

XenDesktop Launch Time with Branch

Repeater Low WAN Congestion

Native XenDesktop Launch Time Low WAN

Congestion

XenDesktop Launch Time with BranchRepeater High WAN Congestion

Native XenDesktop Launch Time High WAN

Congestion

Seconds

XenDesktop Launch Time



Internet Explorer Workflows

Internet Explorer browsing through a virtual desktop can be more bandwidth intensive than Office.

Figures 5 and 6 show the average bandwidth consumed per user across the WAN as users are added

to the environment and the total bandwidth consumed across the WAN for all users executing the

Internet Explorer workflow respectively.

Figure 5: Internet Explorer Workflow-Average Bandwidth Consumed per User

Average Bandwidth Consumed per User

In the Average Bandwidth Consumed per User graph, the average bandwidth consumed line flattens

as the number of users continues to increase. The Internet Explorer workflow was more bandwidth

intensive than the Office workflow and the end user experience began to degrade around 12 users.

Therefore, the average bandwidth per user required for the Internet Explorer workflow for native

XenDesktop was extracted from the 10-12 user range and is approximately 85 kbps per user. When

the Branch Repeater was introduced into the environment, the average bandwidth per user requiredfor the Internet Explorer workflow was reduced by 55% to a more WAN-friendly 38 kbps per user

while maintaining an excellent user experience overall.

0.00

20.00

40.00

60.00

80.00

100.00

120.00

0 2 4 6 8 10 12 14 16

A v g B a n d w i d t h C o n s u m e d

p e r U s e r ( k b p s )

Users


XenDesktop Average Bandwidth per User (Native)

XenDesktop Average Bandwidth per User (with Branch Repeater)



Figure 6: Internet Explorer Workflow-Bandwidth Consumed for All Users

Bandwidth Consumed for All Users

When reviewing the Bandwidth Consumed for All Users graph, the data indicates that total average

bandwidth in the 10-12 user range is approximately 900 kbps for native XenDesktop and 425 kbps

with Branch Repeater. Given that a Branch Repeater user consumes only 38 kbps, then 12.5additional users could be added to the environment to reach the same level of WAN utilization

shown without a Branch Repeater. In other words, the user count supported across a WAN link can

be doubled for Internet Explorer based workflows when a Branch Repeater solution is in place.

Printing Workflows

Figures 7 and 8 show the performance data for printing both a Microsoft Word and PDF document

installed on the local desktop to a printer in the remote branch office for a single user.

0

200

400

600

800

1000

1200

1400

0 2 4 6 8 10 12 14 16

A v g D a t a B a n d w i d t h

( k b p s )

Users


XenDesktop Average Bandwidth (Native)

XenDesktop Average Bandwidth (with Branch Repeater)



Figure 7: Printing Workflow-Total Bandwidth per Print Job

Total Bandwidth

The protocol acceleration benefits of Branch Repeater are very pronounced in a data transfer

situation such as the print workflow. The Total Bandwidth per Print Job graph shows that with a

Branch Repeater solution the data transfer is reduced by 84% for the 5MB Word document and by

89% for the 5MB PDF document.

Figure 8: Printing Workflow-Average Bandwidth Consumed per Document

0 500 1000 1500 2000 2500

5MB PDF Native XenDesktop

5MB Word Native XenDesktop

5MB Word XenDesktop with Branch

Repeater

5MB PDF XenDesktop with Branch

Repeater

Total Bandwidth (KB)

Printing Workflow

0 100 200 300 400 500 600 700

5MB Word Native XenDesktop

5MB PDF Native XenDesktop

5MB Word XenDesktop with Branch

Repeater

5MB PDF XenDesktop with Branch

Repeater

Avg Bandwidth (kbps)

Printing Workflow



Average Bandwidth Consumed per Document

Determining the average bandwidth consumed per user is difficult given the variation in content and

file size for a larger number of users. Instead, the Consulting team recommends determining

guidance for the average bandwidth consumed per document. Once the guidance for document

bandwidth requirements is determined, the end user print behaviors must be identified. Thefollowing numbers represent a single user executing a print job on a T1 with all bandwidth available

for the single print request (maximum bandwidth consumed). Please note that the results will be

different on a congested WAN.

Document Average Bandwidth

(kbps)

Time to SpoolPrint Job(seconds)

NativeXenDesktop

5MB Word 593 kbps 28s

5MB PDF 533 kbps 31s

XenDesktop with

Branch Repeater

5MB Word 180 kbps 15s

5MB PDF 155 kbps 12s

Table 3: Printing Workflow

If the branch office user community does a significant amount of printing, then the Consulting team

recommends utilizing the XenDesktop policies to configure session limits on the amount of

bandwidth a print job can consume. There will be a time trade-off for implementing the

XenDesktop policy, but the end user experience in the virtual desktop will not be as impacted when

a large print job is spooling over the WAN. When a Branch Repeater is configured in the

environment, then the Consulting team recommends configuring the Branch Repeater to prioritize

print traffic relative to other (ICA and non-ICA) traffic, rather than just limiting the bandwidth to a

set amount for printing. With Branch Repeater traffic prioritization (QoS), the Branch Repeater can

prioritize the accelerated traffic to ensure that all available bandwidth is consumed.

Video Workflows

The video workflows were separated into three distinct: HDX MediaStream for Standard Windows

Media Video, HDX MediaStream for High Definition Windows Media Video, and Flash Video

(Server-side Rendering).



Figure 9: Video Workflow-Average Bandwidth Consumed per User

Flash Video (Server-side Rendering)

The WAN connection selected for the test data shown throughout this document was configured

for 80ms latency roundtrip. (HDX MediaStream for Flash can render Flash content on the user

device, thereby increasing server scalability, only if the connection latency is below 30ms roundtrip.)

For all the testing in this document, the latency was configured to 80ms roundtrip, this then forced

XenDesktop to render the Flash video server-side. (QuickTime and Silverlight videos are similarly

rendered server-side.)

As Figure 9 shows, the benefits of introducing a Branch Repeater into a server-side rendered video

provides an average bandwidth consumed savings of approximately 25%. The average bandwidth

consumed for native XenDesktop rendering server-side was 174 kbps while the average bandwidth

consumed with Branch Repeater was 128 kbps.

0 50 100 150 200

MediaStream for Flash Native

XenDesktop

MediaStream for Flash for XenDesktop

with Branch Repeater

Avg Bandwidth per User (kbps)

Video Workflow - Flash



Figure 10: Video Workflow-Average Bandwidth Consumed per Video

HDX MediaStream for Standard WMV

The Standard WMV file was fetched on the server-side and rendered on the client utilizing the HDX

MediaStream technology. This configuration allows the video to be sent to the end-user device in its

compact native format versus sending frame updates as represented in the Flash video results.

When the WMV file is sent to the client for rendering, the data transfer time of that WMV file does

not continue for the entire duration of the video. For example, in this test the total data transfer

time of the standard WMV file for native XenDesktop was approximately 400 seconds. When the

video was played, there was an original spike in data transfer at the start of the video varying

between 30 to 100 seconds based on the number of videos actively playing (a maximum of four

simultaneous videos were played for this test). Then the data transfer drops off and the rate

becomes very marginal. The graph in Figure 10 only shows the average bandwidth consumed

during the intial data spike.

When the Branch Repeater is introduced into the environment, the spike in data transfer time was

reduced by the amount of data transferred during the spike and the duration the spike appeared.

The bandwidth consumption for this standard WMV file with Branch Repeater spiked in the first 10

to 30 seconds and then remained below 10 kbps for the remainder of time the video played. The

average bandwidth consumed for the WMV file with native XenDesktop was approximately 464

kbps during the data spike; whereas, the average bandwidth consumed for the WMV file with

Branch Repeater was approximately 148 kbps, a reduction of 68%. The average bandwidth

measurements only focused on the data spike timeframe rather than the entire video play time to

provide a better representation of the actual data transfer rate required.

0 200 400 600

MediaStream for Native XenDesktop

MediaStream for XenDesktop with

Branch Repeater

Avg Bandwidth per Video (kbps)

Video Workflow - Standard WMV



Figure 11: Video Workflow-Average Bandwidth Consumed per Video

HDX MediaStream for High Definition WMV

The High Definition WMV file required more bandwidth than the standard T1 connection used for

all other test scenarios to transfer the data to the user device for rendering. To provide the best

possible bandwidth guidance for a High Definition video, it was determined that the WAN

connection would be increased from 1.5 mbps to 10 mbps for the HD video testing to ensure that

the effective amount of available bandwidth was greater than the 6.5mbps data rate of the video.

The latency and the packet loss were still consistent with 80ms roundtrip latency and 1% packet loss.

The HD video was fetched on the server-side and rendered on the client. This configuration allows

the video to be sent to the end-user device in its native format versus sending frame updates.

If the remote user had a connection lower than the default threshold of 524kbps for client side

rendering of HDX MediaStream for Windows or was unable to utilize the local client resources for

video rendering, then the HD video would render within the virtual desktop on the server and send

individual frames across the WAN connection to ensure that the user could still see the video and

access the virtual desktop although the quality would be degraded.

Unlike the standard video, the data transfer was high for the entire duration of the video. Only

when the Branch Repeater was introduced into the environment did the data transfer spiked at the

beginning of the video and then remainded marginal for the remainder of time that the video played. This is mentioned because the average bandwidth consumed for the HD WMV file with native

XenDesktop was approximately 1812 kbps during the entire video; whereas, the average bandwidth

consumed for the WMV file with Branch Repeater was approximately 206 kbps with a data spike

only for a brief moment at the start of the video. These numbers show that introducing a Branch

Repeater solution into a high definition WMV video environment would show approximately 89%

reduction in the average amount of bandwidth consumed per HD video.

0 500 1000 1500 2000

MediaStream for XenDesktop with

Branch Repeater

MediaStream for Native XenDesktop

Avg Data Throughput per Video (kbps)

Video Workflow - High Definition Video



Conclusion

In conclusion, this paper provides customers with guidance for determining the amount of

bandwidth required to transition branch office employees from a local desktop to a virtual desktop

hosted on Citrix XenDesktop. The graph shown in Figure 12 provides a collective representation of

all the average bandwidth requirements discussed in this document.

Figure 22: Average Bandwidth Consumed per Session

When reviewing the test results represented in Figure 12 and integrating those results into a unique

customer environment, the following key topics should always be considered for any bandwidth

assessment exercise:

1. The process for determining the bandwidth requirements for a XenDesktop solution in a

branch office should always start with having a good understanding of the applications and

current network demand that the branch office employees have on the existing WAN

connection. The application specific bandwidth numbers in this document should provide

guidance for common applications, but more intricate applications such as a CRM or ERP

system should be thoroughly evaluated before making any conclusions regarding WANrequirements.

2. WAN utilization is another key component to consider when evaluating the WAN

connection. When assessing WAN utilization, it should not be assumed that the average

bandwidth consumed for all users should consume 100% of the available bandwidth. If

possible, the virtual desktop performance should be measured when the WAN connection is

congested to determine the acceptable overall percent of average WAN utilization before

user performance is impacted. To ensure that enough bandwidth is available, the maximum

0

200

400

600

800

1000

1200

1400

1600

1800

2000

Office Internet

Explorer

Printing:

Word

Printing: PDF Flash Video

(server

rendered)

Standard

Video

High

Definition

Video

k b p s

Average Bandwidth Consumed per Session

Native XenDesktop XenDesktop & Branch Repeater



WAN utilization must be based on the most network intensive time of the day and the

effective available bandwidth.

3. Although sometimes difficult to predict, future users and application changes can also affect

the bandwidth requirements sooner than expected. The WAN connection selected should

have the potential for company growth without hindering existing user experience.

4. The other key factor when looking to optimize an existing or future WAN connection aspredominantly shown throughout this paper is the introduction of a Citrix Branch Repeatersolution into any branch office environment. As repeatedly shown throughout the results inthis document, the Citrix Branch Repeater can optimize a WAN connection, improve theoverall user experience, and potentially double the amount of users on an existing WANconnection.



Appendix A - Hardware and Software Configurations

The Consulting Solutions lab located in Fort Lauderdale, Florida provided the following hardware

and software for this report in conjunction with our partnership with Login Consultants:

Component Operating system HardwareXenServer Pool Hosting

Virtual Desktops XenServer 5.5.0 4 physical HP DL360G5

2x Dual Core 2.66 Hz Intel XeonProc, 16GB RAM, 2x72GB hard

drivesXenServer Hosting

Infrastructure XenServer 5.5.0 HP DL360G5

2x Dual Core 2.66 Hz Intel XeonProc, 16GB RAM, 2x72GB hard

drivesXenServer Hosting

XenDesktop Environment XenServer 5.5.0 HP DL360G5

2x Dual Core 2.66 Hz Intel Xeon

Proc, 16GB RAM, 2x72GB harddrives

XenServer HostingBranch Office Environment

XenServer 5.5.0 HP DL360G52x Dual Core 2.66 Hz Intel XeonProc, 16GB RAM, 2x72GB hard

drivesComponent Operating system Hardware

Login VSI File Share Windows Server2003 R2 SP2

HP DL360 G5 2.5Ghz Intel XeonProc, 1GB RAM, 1x72GB hard drive

Branch Repeaters Version 5.5.1Build 58.191613

Model 8520 (pair)

Apposite WAN Emulator Version 4.0.1 Apposite Linktropy Mini

Table 4: Physical Hardware

Virtual Component Operating system Virtual Hardware

Virtual Desktops Windows XP SP3 1GB RAM, 1 vCPU

SQL Server Windows Server 2008 2GB RAM, 2 vCPUs Active Directory Windows Server

2003 R2 SP21GB RAM, 1 vCPU

Citrix License Server Windows Server 2008 1GB RAM, 1 vCPUCitrix Provisioning Services Windows Server

2003 R2 SP21GB RAM, 1 vCPU

Citrix Delivery Controller with Web Interface

Windows Server2003 R2 SP2

2GB RAM, 2 vCPUs

Login VSI Launcher Windows Server2003 R2 SP2

4GB RAM, 2 vCPUs

Print Server Windows Server2003 R2 SP2

1GB RAM, 1 vCPU

Table 5: Virtual Hardware



Software Version

Login VSI Pro Version 2.0Microsoft Office Office 2007 SP1

Microsoft SQL Server SQL Server 2005Citrix XenDesktop Version 4

Citrix Provisioning Services Version 5.1.1.2950Internet Explorer Version 7 Windows Media Player Version 11

Real Player Version 1.0.5Build 12.0.0.343

Table 6: Software Applications used in the report

Appendix B - Citrix XenDesktop Configurations

Property Setting

Farm-Wide Properties

Connection Access Controls Any Connection

Desktop Delivery Controller\Session Reliability Disabled

ICA\Auto Client Reconnect Reconnect automatically

ICA\Keep-Alive 60 seconds

HDX\Browser Acceleration Browser Acceleration: Enabled

Image Compression levels: Medium

Variable Image compression: Enabled

Flash Enable Adobe Flash Player

Desktop Group Properties

Basic\Assignment Type Pooled

Advanced\Client Options Colors: True Color (24-bit)

Connection:

Encryption; 128-Bit Login Only (RC-5)

Connection Protocols: ICA

Advanced\Logoff Behavior Restart the virtual desktop

Citrix Policies

Bandwidth\Visual Effects\Turn off menu animation Enabled - Turn off Menu and Window Animations

Bandwidth\Visual Effects\Turn off window content

while dragging

Enabled - Turn off window content while dragging

SpeedScreen\Image acceleration using lossy

compression

Enabled

Compression level: Medium compression; good

image quality

Session Limits\COM Ports Disabled

Session Limits\LPT Ports Disabled

Session Limits\OEM Virtual Channels Disabled

Session Limits\TWAIN Redirection Disabled

Client Devices\Resources\Audio\Microphones Enabled - Use client microphones for audio input

Client Devices\Resources\Audio\Sound Quality Enabled – Medium sound quality; good

performance



Client Devices\Resources\Drives\Connection Enabled – Connect Client Drives at Logon

Client Devices\Resources\Drives\Mappings Enabled

Turn off Floppy disk drives

Turn off CD-ROM drives

Turn off Remote drives

Client Devices\Resources\Optimize\Asynchronouswrites Enabled – Turn on asynchronous disk writes toclient disks

Client Devices\Resources\Ports\Turn off COM

ports

Enabled – Turn off client COM ports

Client Devices\Resources\Ports\Turn off LPT ports Enabled – Turn off LPT ports

Client Devices\Resources\PDA Devices Disabled

Client Devices\Resources\Other\Turn off OEM

virtual channels

Enabled – Turn Off OEM Virtual Channels

Client Devices\Maintenance\Turn off auto client

update

Enabled – Turn off Client Update

Printing\Client Printers\Auto-creation Enabled – Auto-create the client’s default printer

only

Printing\Client Printers\Legacy client printers Disabled

Printing\Drivers\Universal driver Enabled – Use universal driver only if requested

driver is unavailable

Security\Encryption\SecureICA encryption Enabled –RC5 (128-bit) logon only

Appendix C – Citrix Branch Repeater Configurations

Property Setting

Bandwidth Management>Status Softboost

Bandwidth Management>BandwidthScheduler>Bandwidth Consumption

Full Bandwidth

Bandwidth Management>Bandwidth

Scheduler>Bandwidth Limit (Send):

1425kbps

Bandwidth Management>Bandwidth

Scheduler>Bandwidth Limit (Receive)

1425kbps

Service Class Policy>ICA Accelerate

Disk based Compression

Service Class Policy>HTTP Accelerate

Disk based Compression

Appendix D – Login VSI Pro Configurations

Property Setting

VSI Launcher Configuration

Type of connection Custom with CSV

User Credentials NA

Number 1 to n (Varied based on workflow)



Interval Custom

Custom Command line Custom

Location of csv file File Share Path (datacenter)

Auto log off No

VSI Workflow

Office 2007 Customized MEDIUM workflow to execute Officeonly – VSI Pro Feature

IE 2007 Customized to run CORE workflow that executes

custom AutoIT based IE browsing script – VSI Pro

feature

Video Customized to execute Flash, standard WMV, and

HD WMV video

Appendix E – HDX MediaStream Active Directory GPOs

HDX MediaStream for Flash is enabled or disabled through Active Directory Group Policy Objects(GPOs). The Citrix support provides two ADM templates that can be imported into theenvironment: HDX-Flash-Client and HDX-Flash-Server. Both of these templates are found on theXenDesktop 4 media in the W2K3\En\Support\Configuration folder.

Once the HDX-Flash-Client and HDX-Flash-Server ADM templates were imported into the GPOthat applied to the XenDesktop test users, the following settings were made:

Enable HDX MediaStream for Flash on the user device: Enabled

Enable server-side content fetching: Enabled

Enable HDX MediaStream for Flash for connections to the server: Enabled

Server-side content fetching list: Enabled and set to * so all URLs would be fetched

Appendix F - References

Login Consultants’ Login VSI Pro Benchmarking Tool:

http://www.loginvsi.com

Citrix HDX Technologies: http://hdx.citrix.com

High Definition Windows Media Video (robotica.wmv):http://www.microsoft.com/windows/windowsmedia/musicandvideo/hdvideo/contentshowca

se.aspx

HDX MediaStream for Flash Information:http://www.citrix.com/tv/#videos/635

HDX MediaStream GPO Configurations:

http://www.loginvsi.com/


http://hdx.citrix.com/


http://www.microsoft.com/windows/windowsmedia/musicandvideo/hdvideo/contentshowcase.aspx



http://www.citrix.com/tv/#videos/635









http://support.citrix.com/proddocs/index.jsp?lang=en&topic=/xenapp5fp2-w2k3/hd-flash-configure.html

http://support.citrix.com/proddocs/index.jsp?lang=en&topic=/xenapp5fp2-w2k3/hd-flash-configure.html%20






Revision Change Description Updated By Date

0.1 First draft Bhumik Patel & Carisa Stringer January 22, 2010

0.2 QA Paul Wilson January 28, 20100.3 Update Bhumik Patel & Carisa Stringer February 10, 2010

0.4 Final Version Bhumik Patel & Carisa Stringer March 5, 2010

About Citrix

Citrix Systems, Inc. (NASDAQ:CTXS) is the leading provider of virtualization, networking and software as a service

technologies for more than 230,000 organizations worldwide. It’s Citrix Delivery Center, Citrix Cloud Center (C3)

and Citrix Online Services product families radically simplify computing for millions of users, delivering applications

as an on-demand service to any user, in any location on any device. Citrix customers include the world’s largest

Internet companies, 99 percent of Fortune Global 500 enterprises, and hundreds of thousands of small businesses

and prosumers worldwide. Citrix partners with over 10,000 companies worldwide in more than 100 countries.

Founded in 1989, annual revenue in 2008 was $1.6 billion.

©2010 Citrix Systems, Inc. All rights reserved. Citrix®, Access Gateway™, Branch Repeater™, Citrix Repeater™,

HDX™, XenServer™, XenApp™, XenDesktop™ and Citrix Delivery Center™ are trademarks of Citrix Systems, Inc.

and/or one or more of its subsidiaries, and may be registered in the United States Patent and Trademark Office

and in other countries. All other trademarks and registered trademarks are property of their respective owners.

xendesktop to branch offices_v2

Documents