If you receive errors when attempting to view this white paper, please install the latest version of
Adobe Reader.
"As a significant percentage of Presentation Server customers have their applications delivered over remote WAN links,
finding ways to improve the speed and the end user experience is a goal of
WAN optimization solutions. Also, by being able
to tap into such a large pool of potential users is extremely enticing for all WAN optimization organizations."
Source : Citrix
How to Boost your WAN to Top Speed
WAN is also known as :
WAN,
Wide Area Network,
WAN Computer Network,
WAN Monitoring Software,
Better WAN Monitoring,
WAN Analysis,
Complete WAN LAN Analysis,
WAN Network Emulator,
Data WAN Info,
Data WAN Access,
Monitor WAN Easily,
WAN Definition,
Term Wide-Area Network,
Report WAN's Shaping,
Router Switch WAN,
Wide-Area Network Lists,
Test Performance WAN Apps,
Frees/WAN Project,
WAN and Broadband News,
Switch WAN,
Language Code WAN,
Report for Language Code WAN,
WAN Optimization,
Ensure WAN,
Storage Area Networking,
WAN Optimization Storage,
Wide Area Network WAN Spans,
WAN Interface,
Voice WAN Interface,
WAN Contains,
WAN Bandwidth Optimization,
Dynamic Internet WAN IP,
Protocols for WAN IP,
WAN Products,
WAN IP Address Detection,
Beyond WAN Optimization,
Download WAN Network Map,
WAN Protocols,
WAN Technologies,
Free Wide Area Network.
A guide to fast
application delivery
at the branch
The trend toward globalization is propelling the branch office
front and center of the enterprise. Meanwhile, concurrent moves
toward consolidation are centralizing IT operations back at
corporate headquarters. Increasing the distance between the
application user and the application causes poor application
performance and reduces worker productivity at the branch
- where business needs it most.
This brief takes a close look at these emerging trends and how
they impact the network, application delivery and, ultimately, the
end user experience at the branch office. You'll find out how to
make your WAN work like a LAN through a simple, cost-effective
solution that will meet these challenges now and into the future.
ENTERPRISE GLOBALIZATION MEETS
IT CONSOLIDATION
Welcome to Make Your WAN Work Like a LAN: A Guide to
Fast Application Delivery at the Branch. Delivering important
applications quickly to business frontlines is mission critical
in today's increasingly distributed enterprise. If branch office
application performance over the wide area network (WAN) is
not living up to expectation, and you want LAN-like speeds from
your WAN, then read on.
The Changing World of the Enterprise
Two distinct trends are transforming the way organizations do
business. Globalization is opening up new opportunities with
greater geographic reach. Meanwhile, IT consolidation is bringing
the focus back to corporate or datacenters. With business
transactions far afield and IT at headquarters, the network is
feeling the tension. Unprecedented demands on enterprise
WANs are compromising application performance, file and data
access, user productivity and the business bottom line.
- Going Global
Moving key business functions, and your workforce, out
of headquarters and into the field alongside your
customers and suppliers makes good business sense. To
maintain a regional foothold, a global organization must
establish a strong local presence. Also, trends toward
business process outsourcing and worker mobility are
further driving globalization.
- The Move Toward IT Consolidation
Pressure to cut costs, assure accuracy and security as
well meet regulatory compliance (e.g. Sarbanes-Oxley
Act) is pushing the move toward application and data
storage and server consolidation - with data easier
to control at the datacenter. Centralized data, along with
application single hosting, enables business processes at
one datacenter to serve the entire organization.
- The Rise of the Branch Office
The branch office has emerged as the key customer touch
point and critical to business success. Now making
up over 50 percent of the workforce, branch office
personnel need access to the same applications -
customer relationship management (CRM), enterprise
resource planning (ERP) and office productivity tools - as
at headquarters. Only, these key applications now reside
at the datacenters.
The New World of the Enterprise
Today's enterprise conducts most of its business at the branch office while
corporate data and IT services are back at headquarters.
Feeling the Pain
THE BRANCH IS WHERE IT HURTS
These growing trends are compelling business to rely more and
more on the network to fill in the gap between the datacenter
and the branch office. Yet, today's networks aren't equipped to
handle these new demands.
Increased Demand on the WAN
The WAN is now facing a huge increase in network traffic that
once traveled short distances over a large-capacity LAN now
traversing states, countries and even continents over a lesscapacity
WAN. With streaming video, remote backups, voice over
IP (VoIP), etc. jamming network pipes, the WAN can slow to a
crawl. And it does.
Branch Office Breakdown
When the WAN falters, critical business application data
doesn't reach its destination on time, if at all. Branch workers
experience slow response times - with email, ERP and CRM,
for example - while slow file access curtails productivity and
collaboration. And IT managers face slow backup and restore,
undermining data integrity and security. Yet, IT must ensure the
same high performance and reliability they once delivered over
the LAN, while also cutting costs and increasing security through
consolidation.
Latency Takes Its Toll
TRAVEL THE DISTANCE
Latency is the key culprit in slow branch office application
delivery. No matter how fast the WAN circuit - or its
implementation (VPN, MPLS, Frame Relay, etc.) - WAN
throughput decreases as WAN distance increases. Sheer
distance, alone, contributes to latency; however, other factors
are also to blame.
TCP Limitations
TCP/IP is notoriously inefficient in coping with high-latency
connections, where TCP windows don't adjust rapidly. When
a packet drops, for example, data recovery mode reduces the
window in half and resends missing packets and/or the entire
TCP window.
Chatty Protocols
Chatty protocols - such as CIFS (Windows drag and drop) and
MAPI (email) - require several communication exchanges in
order to open a connection and transfer data. It may take tens or
hundreds of round trips to complete a single transaction.
Packet Loss
Dropped packets can impact network performance. When a
packet becomes lost or corrupt in transit, the system discards
the bad packet and requests a resend of data, causing all other
packets in transit to backtrack to the beginning of the sequence.
Network Congestion
Competition for the same share bandwidth leads to WAN
congestion and delayed or dropped traffic, slowed throughput
and many packet retransmissions. With IT consolidation, data
used or changed in each branch office must now traverse the
WAN on its way back and forth to the datacenter.
The Trouble with Chatty Protocols
With chatty protocols, the end user has to wait for a large number of small
application messages traveling over great distances to complete before
proceeding - dramatically impacting application performance.
Pain Relievers
BREAK WITH TRADITION
In response to these challenges, IT managers often turn to
traditional approaches, especially when looking for a quick fix to
performance issues. However, what might have worked in the
"old" enterprise won't necessarily stand up in the new. Let's take
a look at some of these traditional approaches.
Setting Thresholds for WAN Utilization
A common technique is to adjust WAN bandwidth in response
to network utilization, adding resources when utilization exceeds
a threshold - often in the range of 70 to 80 percent. Setting
thresholds assumes that performance problems are caused by
heavy latency-sensitive network traffic, which isn't the case with
email and bulk file transfers.
Adding More Bandwidth
Adding bandwidth, an expensive proposition, is one solution
to threshold crossing, but it doesn't necessarily resolve all
performance issues. And it will increase ongoing IT costs.
More importantly, it doesn't get at the root cause or address
other factors such as chatty protocols, data speed on the wire,
number of round trips for a single transaction or the impact of
various intermediate WAN devices. It's not enough just to add more resources, you also need to minimize latency effects and
match resource allocation to business needs.
Reaching for Point Products
There are many individual products on the market that address
specific network issues - accelerators, compression tools,
routers, etc. The temptation is to piece them together to come
up with a workable solution. However, unless these products are
built to work together, they probably won't integrate with each
other or with other network tools and technology, only adding
more complexity to the mix.
The Solution:
Fast Application Delivery at the Branch
ACHIEVING LAN-LIKE PERFORMANCE OVER
THE WAN
The best way to meet the demands of the new enterprise
environments is through a comprehensive branch office
application delivery infrastructure that delivers the tools and
technology needed to ensure top performance and data integrity
without adding complexity and cost. You need a solution that
makes the most of what you already have, and more. One that
will deliver the high level of performance you demand now and
for whatever comes next.
Best-in-Class Optimization Technologies Deliver High
Performance
The right solution gets applications and data quickly and
efficiently to the branch using innovative tools and technology
that work to mitigate the effects of latency, optimize chatty
protocols and cut down the number of packets needed to
transfer data. The following technologies will ensure that
applications are delivered to the branch at LAN-like speed over
the WAN:
- Adaptive TCP Flow Control Mechanisms to optimize
bandwidth utilization by automatically detecting and
adjusting network usage.
- Multi-level Compression to reduce congestion and
make the most of existing bandwidth by shrinking data
size before transmission over the WAN.
- Protocol-specific Accelerators to reduce chattiness
and resulting WAN delays by reducing round trips and,
therefore, effective latency for CIFS, NFS, HTTP, and FTP
protocols.
The Benefits of Fast Branch Office Application Delivery
- Deliver LAN-like performance at the branch
- Capitalize on cost savings with IT resource consolidation
- Protect data centrally
- Accelerate all TCP-based enterprise applications
- Provide application luency for faster data transfers
- Extend collaborative worklows and improve productivity
- Improve application throughput in heavily congested
environments
Less is More
Complexity does not equal sophistication. These high
performance tools can be easily deployed using an unobtrusive
appliance-based approach. A simple appliance - at the data
center and the branch - can greatly impact performance
without comparable impact on your network. Everything stays
intact; only your important applications and data get to their
destinations safely and on time.
- Network Transparency
The right solution should install transparently into your
existing network infrastructure, allowing your network
to function as it did before - only better. No changes
needed to firewalls or routers, monitoring probes or
applications and no impact on security or quality of service
(QoS). Installation is seamless with little to no configuration
and setup, and the network dynamically self-tunes for
optimal performance based on real-time conditions.
- Low Maintenance
As branch office IT will be limited, the solution should be
easy to deploy and maintain. You should be able to continue using your existing set of applications and
management tools. Even with a great number of appliances,
there shouldn't be any need for extensive product-specific
training or professional IT expertise for day-to-day
maintenance or troubleshooting.
Branch Office Application Delivery Infrastructure
An effective branch office application delivery infrastructure will ensure top
performance at the branch without adding complexity and cost.
The Application Delivery Triumvirate
THE THREE POWER TOOLS OF FAST
BRANCH PERFORMANCE
At the heart of the ideal branch office application delivery
system are three advanced technologies working in concert to
intelligently adapt to changing network conditions to fully utilize
existing bandwidth over any distance, reduce round trip times
and speed up file access.
Adaptive TCP Flow Control
Make the Most of Your Link
To optimize bandwidth utilization, Adaptive TCP Flow
Control automatically detects and adjusts network
consumption based on real-time network conditions.
Adaptive TCP Flow Control allows senders to transmit only
as much data as the network can accommodate to
eliminate overflows and ensure that all senders fully utilize
available bandwidth.
Multi-level Compression
Go for Maximum Throughput
To reduce the amount of data traversing the WAN,
compression shrinks data size before transmission,
alleviating congestion on the shared link and improving
overall application performance without WAN upgrade costs. Applying different types of compression to deal with
different applications and situations makes the most of existing bandwidth.
Protocol-specific Acceleration
Optimize with Application-fluent Precision
To reduce net latency, protocol-specific accelerators
increase the numbers of packets that can be transmitted
without receiving acknowledgement. This mitigates
the impact of chatty protocols by cutting back on
redundant application messages. Accelerators that
are optimized explicitly for CIFS, NFS and HTTP will
ensure these protocols run at optimal performance.
Combined with compression, protocol-specific
acceleration moves files and content faster.
Protocol-specific Acceleration
Protocol-specific acceleration localizes traffic flow to reduce chattiness and the
effects of latency.
The Importance of
Network Transparency
SEAMLESS NETWORK INTEGRATION
Your branch office application delivery infrastructure should be
built on a transparent network (and application) architecture,
preserving the key characteristics of traffic flow on the WAN - like
IP addresses, port numbers and protocols (TCP or UDP). Other
solutions may claim application transparency, but not network
transparency, which has broader implications for the WAN,
performance and IT management.
What Transparency Means to the Network
With transparency, your network essentially behaves as it
did without the new system, but even better. Only networktransparent
devices interoperate with other networking products
- firewalls, monitoring, QoS devices - without reconfiguration or
the need to create proprietary TCP or UDP tunnels or replace
network addresses and other identification fields. No need to
rework QoS or traffic tagging, change network security policies
or redirect end user applications - making the system easy to
maintain and support.
The Trouble with Tunnels
Experienced administrators know it's better to administer the
network without having to build or maintain tunnels. Tunnels
have significant limitations. They typically require additional set up and configuration, often requiring non-standard ports to be
opened in firewalls to allow optimized traffic to pass, for example.
When network routes change, for example, tunnels can lead to
unpredictable behavior or even complete loss of connectivity.
Tunnels Interfere with Critical Network Services
Unlike Citrix WANScaler, solutions that tunnel interfere with network services
like QoS, security, and monitoring. Tunneling solutions increases deployment
complexity, introduces risks to the network, and requires costly reconfiguration
of the network so critical network services are once again available. The
complexity and risks associated with tunneling solutions necessitate more
ongoing IT management and thus higher overall total cost of ownership
compared to Citrix WANScaler.
The Benefits of Network Transparency
- Installs fast; easy to get up and running
- Integrates quickly with no coniguration of network, irewalls,
security policies, routers or clients
- Works with all network devices, applications and WAN
technologies
- Won't break downstream and interfere with QoS or irewalls
- Enables visibility for monitoring above Layer 4
- Dramatically reduces ongoing maintenance and management
Branch Ofice
Application Delivery Checklist
FOR GREAT PERFORMANCE, HAPPY END
USERS, IMPRESSIVE BOTTOM LINE
Fast branch office application delivery enables IT to keep up with
the changing world of the enterprise. But not just any system
will do. The right approach will make your WAN work like a LAN
and elevate productivity at the branch where it's needed most.
Use the following checklist as a quick reference to guide you
to the right tools and technology. Then, enjoy great application
availability and performance at the branch, on the road or
wherever you do business.
- Best-in-class WAN Optimization Technologies - with adaptive
TCP flow control mechanisms, multi-level compression and
protocol-specific accelerators
- Fully Transparent Network Architecture - for seamless
integration into your existing network with no need to reconfigure
or create intrusive tunnels
- Quick Plug N' Play Install - to get up and running in no time
- Simple Appliance-based Solution - to bring high performance
to the branch with minimum cost and maintenance
About Citrix
Citrix Systems, Inc. (Nasdaq:CTXS) is the global leader and the
most trusted name in application delivery infrastructure. More
than 180,000 organizations worldwide rely on Citrix to deliver
any application to users anywhere with the best performance,
highest security and lowest cost. Citrix customers include 100%
of the Fortune 100 companies and 98% of the Fortune Global
500, as well as hundreds of thousands of small businesses and
prosumers. Citrix has approximately 6,200 channel and alliance
partners in more than 100 countries. Annual revenue in 2006
was $1.1 billion.
CITRIX WORLDWIDE
WORLDWIDE HEADQUARTERS
Citrix Systems, Inc.
851 West Cypress Creek Road
Fort Lauderdale, FL 33309 USA
Tel: +1 (800) 393 1888
Tel: +1 (954) 267 3000
EUROPEAN HEADQUARTERS
Citrix Systems
International GmbH
Rheinweg 9
8200 Schaffhausen
Switzerland
Tel: +41 (52) 635 7700
ASIA PACIFIC HEADQUARTERS
Citrix Systems
Hong Kong Ltd.
Suite 3201, 32nd Floor
One International Finance Centre
1 Harbour View Street
Central
Hong Kong
Tel: +852 2100 5000
CITRIX ONLINE DIVISION
5385 Hollister Avenue
Santa Barbara, CA 93111 USA
Tel: +1 (805) 690 6400
TABLE OF CONTENTS
- Feeling the Pain
The Branch is Where it Hurts
- Latency Takes Its Toll
Travel the Distance
- Pain Relievers
Break with Tradition
- The Solution: Fast Application Delivery at the Branch
Achieving LAN-like Performance over the WAN
- The Application Delivery Triumvirate
The Three Power Tools of Fast Branch Performance
- The Importance of Network Transparency
Seamless Network Integration
- Branch Office Application Delivery Checklist
For Great Performance, Happy End Users, Impressive
Bottom Line