4 th October 2012 Optimising network delivery of virtual desktops Jason Poole Business Development Manager, EMEA (Cloud Networking) Michael Aldridge Senior

4th October 2012

Optimising network delivery of virtual desktops

Jason Poole

Business Development Manager, EMEA (Cloud Networking)

Michael Aldridge

Senior System Engineer, EMEA (Cloud Networking)

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Industry trends and IT resources

Centralisation of Resources Multiple devices Distributed workforce

Work and play from any device, anywhereWork and play from any device, anywhere

Change everything… but wait, consideration?Change everything… but wait, consideration?

• Cost reduction

• Business Agility

• Improved security

• Improved compliance

• Ease of management

Why Implement a Desktop Virtualisation Solution?

• Centralisation is a single point of failure• Benefits of Desktop Virtualisation are realised through centralisation

• Branch office workers might experience poor experience• 80% of employees are located away from the HQ and the data centre

• How to provide the access to the virtual desktop• More and more users are bringing their own devices• Requirement for remote access and maintaining security

Considerations for a successful Desktop Virtualisation

Remote Access

Anywhere Access Allows users to securely access desktops and applications using any device in any location, including home computers and mobile devices.

HDX SmartAccessDelivers simple and seamless secure access

Network and device roamingEnables users’ sessions to transparently and securely move between networks and devices by dynamically adapting access.


Anywhere Access

Single sign-onImproves the user’s experience by reducing unnecessary authentication prompts and the number of passwords users need to remember.


Anywhere Access

Network and device roaming

Granular Action ControlAllows the administrators to define capabilities within application to which users have access.


Anywhere Access

Network and device roaming

Single sign-on

Availability

• Goal: Network Infrastructure Fault tolerance

• Roadblocks:• Virtual desktop hosting

platform• Operating system delivery• Application and desktop

delivery• Desktop controllers• Application controllers

High Availability

Datacenter – High Availability

DHCP Built-In Redundancy

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Microsoft DFS

NetScaler Load Balancing

Bootstrap RedundancyProvisioning Services High-Availability

Web InterfaceXenDesktop Controllers Data CollectorWeb Interface

Provisioning Services

TFTP ServersDHCP Servers

XenServer Pool

Application Hub

XenApp Members

Remote UserBranch Office

Home OfficeTablet

NetScaler

Desktop Delivery

Controller

HQ Office

XenDesktop Farm XenServer Resource Pool

Active Directory

Data Store License Server DHCP

Infrastructure

Virtual Desktop 1Virtual Desktop 1

Personalization: User APersonalization: User A

Apps: OfficeApps: Office

OS: VistaOS: Vista


Personalization: User BPersonalization: User B


OS: XPOS: XP


Personalization:Personalization:

Apps:Apps:

OS:OS:

F i

r e

w a

l l

F i

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w a

l l

F i

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F i

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Personalization

Applications

OS

Provisioning Server

XenApp Controller

File Share

Desktop Delivery

Controller

DataCollector

Vista Windows XP

Windows 7

User A

User B

User C

User D

User E

WebInterface

Strong SLAs

Secure Access

Remote UserBranch Office

Home OfficeTablet

NetScaler

Desktop Delivery Controlle

r

HQ Office

XenDesktop Farm XenServer Resource Pool

Active Directory

Data Store

License Server

DHCPInfrastructure




OS: VistaOS: Vista




OS: XPOS: XP



Apps:Apps:

OS:OS:

F i

r e

w a

l l

F i

r e

w a

l l

F i

r e

w a

l l

F i

r e

w a

l l

Personalization

Applications

OS

Provisioning Server

XenApp Controller

File Share

Desktop Delivery Controlle

r

DataCollector

Vista Windows XP

Windows 7

User A

User B

User C

User D

User E

WebInterface

Strong SLAs

Secure Access

Remote User

Branch Office

Home Office

Tablet

NetScaler

Desktop Delivery

Controller

HQ Office

XenDesktop Farm

XenServer Resource Pool

Active Directory Data

Store License Server DHCP

Infrastructure




OS: VistaOS: Vista




OS: XPOS: XP



Apps:Apps:

OS:OS:

F i

r e

w a

l l

F i

r e

w a

l l

F i

r e

w a

l l

F i

r e

w a

l l

Personalization

Applications

OS

Provisioning

Server

XenApp Controller

File Share

Desktop Delivery

Controller

DataCollector

Vista Windows XP

Windows 7

User A

User B

UserC

UserD

UserE

WebInterface

GlobalAvailability

Remote User

Branch Office

Home Office

Tablet

NetScaler

Desktop Delivery

Controller

HQ Office

XenDesktop Farm

XenServer Resource Pool

Active Directory Data

Store License Server DHCP

Infrastructure




OS: VistaOS: Vista




OS: XPOS: XP



Apps:Apps:

OS:OS:

F i

r e

w a

l l

F i

r e

w a

l l

F i

r e

w a

l l

F i

r e

w a

l l

Personalization

Applications

OS

Provisioning

Server

XenApp Controller

File Share

Desktop Delivery

Controller

DataCollector

Vista Windows XP

Windows 7

User A

User B

UserC

UserD

UserE

WebInterface

• Data may not be replicated to all sites

Data Proximity

WAN

North America

EMEA

• Ensure that only ICA traverses the WAN

GSLB with Site Roaming

WAN

North America

EMEA

User ExperienceDeployment across a WAN

• Sexy interface – graphic intensive

• Chatty protocols

• Testing labs• Gigabit connectivity• 0 ms Latency

Citrix Confidential - Do Not Distribute

Applications are designed for the LAN

Deployed across a WAN? Slow? = “that’s a network issue. You fix it.”

HDXICA protocol is an

underlying technology for HDX (High-Definition User

Experience)

• How much bandwidth is enough?

• It depends on:• Other network traffic• Application bandwidth

requirements • Number of users• User behavior• And more!

Bandwidth Allocation for ICA

vs.

• ICA sessions to drop

• Users experience choppy typing or screen paints

• Session Reliability to be invoked (if enabled)• User sees application but can’t use

it

Insufficient Bandwidth Causes . . .

Dear Mr. Templeton,

I love Citrix XenApp!How can I purchasemore licenses?

• Already highly compressed and optimized

• Automatically tunes itself to further compress when less bandwidth available• Single session bandwidth testing not valid!

ICA Compression

ICA Session

WAN Optimisationfor Desktop Virtualisation

What is ICA Optimization?• Enhancements to Repeater compression engine• ICA Encryption/Decryption• The ICA Parser• ICA Intra-Session Compression enhancements• ICA Cross-Session Compression

Adaptive TCPFlow Control

Adaptive TCPFlow Control

Adaptive Compression

Adaptive Compression

Adaptive Protocol

Acceleration

Adaptive Protocol

Acceleration

Traffic Prioritization

Traffic Prioritization

Branch Staging of Streamed Apps

Branch Staging of Streamed Apps

Branch Caching of

Hosted Apps

Branch Caching of

Hosted Apps

ICA Parser• Acts as an intermediate for decryption/encryption

• Can decrypt all ICA encryption except for SSL.• No cert installed on the acceleration pair• Supports Basic, RC-40, RC-56 and RC-128 encryption levels

• Re-encrypts on WAN, transparently to the client.

Branch Repeater Repeater orBranch Repeater

XenApp FarmBranch Client

LAN

Client is relieved of ICA decompression tasks

ICA Connection initializationWS/CBR Compressed Traffic

Decrypt, ICA Parser looks for ICA/CGP

Signature, Re-encrypt.

De-crypt, then either disk based or memory based compression

histories are used, then re-encrypt.

WAN LAN

ICA Parser• ICA compression requests Server/Client are disabled

• Parsing only occurs on accelerated connections.• When a connection is established the ICA handshake is detected.• At that point it is determined if it is ICA or CGP (detected in the connection

payload).



LAN







WAN LAN

ICA Parser• Separates headers from payload and bulk from interactive

• Print/File/Multimedia• Bulk traffic goes to disk (DBC)

• ThinWire graphics commands• Interactive goes to memory (MBC)

• Header data goes to the small matcher (Nano)



LAN







WAN LAN

ICA Compression - Cross session Compression

Branch Repeater Repeater orBranch Repeater XenApp Farm

LAN


Native ICACompression enabled by

defaultWS/CBR Compressed Traffic

WS/CBR turns off XA compression and enables WS compression during

negociation.

Either disk based or memory based compression histories

are used.

WAN LAN

•Subsequent packets are compared to the compression history on the sending side.•Payload matches are substituted with a token in lieu of the whole packet.•The server still sends, and the client still received what they expect to.

ICA Compression - Cross session Compression

Branch Repeater Repeater orBranch Repeater XenApp Farm

LAN


Native ICACompression enabled by

defaultWS/CBR Compressed Traffic

WS/CBR turns off XA compression and enables WS compression during

negociation.

Either disk based or memory based compression histories

are used.

WAN LAN

•After the histories are populated, if a second client requests the same data in his/her ICA session, a second match can occur.•Tokens are sent and the payload is pulled from the client side compression history.•The more users of the same application, the better.

Use Case – ICA Compression of Display Traffic

• Repeatable data bitmaps can be reused for subsequent requests

• Cross-session compression enhanced

Repeatable vs. Unique Data

Unique data

Repeatable data

Use Case - ICA Optimization of Print Traffic

• Repeater compresses using disk (disk-based compression)ᵒ Minus the headersᵒ Second pass of the same print job

• ~70:1 compressionᵒ Small modifications followed by a print-job resend

• Compresses well (35-40:1)

• What is an ICA Virtual Channel?A Citrix Independent Computing Architecture (ICA) virtual channel is a bidirectional connection for the exchange of generalized packet data between a Citrix XenApp/XenDesktop Server and a ICA compliant client.

Virtual channels correspond to virtual drivers; each providing a specific function. Some are required for normal operation, and others are optional.

Virtual drivers operate at the presentation layer protocol level. There can be a number of these protocols active at any given time by multiplexing channels.

There are a total of 64 virtual channels in the ICA protocol. However for most user sessions, between 8 -12 are usually utilized.

ICA Review – Virtual Channels

ICA QoS Single StreamICA Priority Packet Tagging allows prioritization of ICA sessions based on the virtual channel data being transmitted. (what the user is doing within the app/session)

This is done by associating each virtual channel’s two-bit priority to a packet priority.

The two priority bits combine to form four priority values:

00 (0) - High Priority01 (1) - Medium Priority10 (2) - Low Priority11 (3) - Background Priority

These priority bits can then be assigned to Branch Repeater Quality of Service queues to allow dynamic QoS.

The Single Stream ICA Problem

compressed and encrypted ICA data

•The user creates an ICA session.

•User interface traffic is tagged with a priority bit of zero (thin wire).

•Branch Repeater identifies the priority tags in real time and applies QoS appropriately.

Session Bandwidth



•The user then starts a print job within the ICA session.

•Print traffic is tagged with a priority bit of three (real time).

•Branch Repeater identifies the new priority tags in real time and applies QoS appropriately.

Session Bandwidth



•The user then either returns to the app’s user interface or starts a second application. (thin wire)

•The new observed priority bits of the session cause the session to be QoS’ed as a priority zero.

•Prioritization of printing traffic is now lost.

Session Bandwidth

ICA Stream #1(Very High)

ICA Stream #2(High)

ICA Stream #3(Medium)

ICA Stream #4(Low)

Channel Name Default Priority Description Virtual DriverCTXTW 0 Remote Session Screen Update (THINWIRE) vdtw30n.dll

CTXTWI 0 Seamless Windows Screen Update (THINWIRE)

vdtwin.dll

CTXTWN 0 Winstation wfica32.exe

CTXEUEM 0 End User Experience Monitoring vdeuemn.dll

CTXZLFK 0 Local Text Echo and Keyboard Feedback vdzlcn.dll

CTXZLC 0 Speed Screen Latency Reduction - Screen vdzlcn.dll

CTXZLFK 0 Speed Screen Latency Reduction - Fonts vdfon30n.dll

CTXCTL 0 ICA Session Control vdctln.dll

CTXFLSH 1 Multimedia - Flash vdflash.dll

CTXGUSB 1 USB Redirection vdgusbn.dll

CTXMM 1 Multimedia - Streaming vdmmn.dll

CTXCLIP 1 Client Clipboard Mapping vdclipn.dll

CTXCAM 1 Client Audio Mapping vdcamN.dll

CTXLIC 1 License Management wfica32.exe

CTXVFM 1 Video Server – (no longer used) n/a

CTXPN 1 Program Neighborhood vdpnn.dll

CTXCCM 2 Client COM Port Mapping vdcom30N.dll

CTXCDM 2 Client Drive Mapping vdcdm30n.dll

CTXPASS 2 Transparent Key Pass-Through vdkbhook.dll

CTXCPM 3 Printer Mapping for Spooling Clients vdcpm30N.dll

CTXCM 3 Client Management (Auto-Update) vdcmN.dll

CTXLPT1 3 Legacy LP1 Port Mapping wfica32.exe

CTXLPT2 3 Legacy LPT2 Port Mapping wfica32.exe

CTXCOM1 3 Legacy COM1 Port Mapping wfica32.exe

CTXCOM2 3 Legacy COM2 Port Mapping wfica32.exe

Virtual Channels

Multi-Stream ICA Terminology

• Single-port, Multi-stream ICA (MSI Default)ᵒ 4 random ports at client, 1 primary port on serverᵒ Automatically enabled on ICA server by Branch Repeater 6.0.

• Multi-port, Multi-stream ICAᵒ 4 random ports at client, 1 primary and up to 3 secondary ports on serverᵒ Most common deployment if used without Branch Repeater

• Single-port, Single-stream ICAᵒ 1 random port at client, 1 primary port on serverᵒ The pre-MSI default connection typeᵒ If any Branch Repeater on the link vetos MSI, or old versions used

How Does Branch Repeater Optimize ICA?Adaptive orchestration with XenDesktop and XenApp

Branch Repeater

Repeater

PrintThinwire

CDM

PrintThinwire

CDM

Unprecedented visibility into XenDesktop and XenApp traffic

Custom acceleration modes for print, video and file traffic

Minimum changes to underlying XenDesktop or XenApp infrastructure

Branch Repeater with ICA

• Branch Repeater reduces the bandwidth consumed per session by up to 89%

• Branch Repeater can double the number of users on the same WAN connection

• Branch Repeater reduces session launch times by up to 40% and print spooling times by up to 60%

CTX124457: Data Analysis

Santa Barbara

RedmondSchaffhausen

Chicago Bedford

Dallas

Paris

Madrid

Munich

Copenhagen

Vianen

Chalfont

Sydney

Dublin

Miami

Santa Clara

Cambridge

Mexico City

Toronto

Atlanta (DR)

New York CityBethesda

Fort Lauderdale Hong Kong

Tokyo

Singapore

Bangalore

Stockholm

Data center officeRegional headquartersRegional officesDisaster recovery

Citrix-on-Citrix: 56 Branch Repeaters Deployed

Location Branch Repeater Model

Main data centers 8820

Regional/sales offices 8540

Summary

• Industry trends are driving desktop virtualisation as a solution

• The same trends mean there are considerations for successful deployments

• Networks must be optimised to ensure Availability and User experience

• Citrix has the components to ensure Enterprises can realise the benefits of Centralisation, Consumerisation and Geographical dispersion

43

Desktop virtualisation is a solution not a productDesktop virtualisation is a solution not a product

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Documents

4 th October 2012 Optimising network delivery of virtual desktops Jason Poole Business Development Manager, EMEA (Cloud Networking) Michael Aldridge Senior