WAN is the word
Optimization tools boost efficiency and reduce strain on bandwidth.
- By Maggie Biggs
- Jul 09, 2008
Smart sprinters who work to improve their
times don't just work on increasing muscle
mass. They also work on improving technique.
Similarly, adding powerful ? and expensive ?
new equipment isn't the only way to boost performance
of a wide-area network. Technique
counts for a lot, and one technique that can
deliver major gains is WAN optimization.
Organizations that have implemented
WAN optimization have discovered
improved application performance. And
there are several other benefits downstream,
including the ability to consolidate data centers
and servers, centralize and accelerate
backup strategies, improve disaster recovery
capabilities, and reduce bandwidth costs.
Organizations can quickly realize a positive
return on investment with such benefits.
Reduction of bandwith costs is one of the
primary drivers toward WAN optimization.
"WAN optimization can decrease link utilization
from 80 percent to 40 percent by
using [a combination of ] caching and compression,"
said Robert Whiteley, principal
analyst and research director at Forrester
At its core, WAN optimization ? sometimes
also called WAN acceleration ? aims to
improve application performance by increasing
throughput and decreasing latency across network
links. Typically, hardware or software at
both ends of a WAN link work in concert to
achieve optimal performance.
WAN optimization commonly encompasses
four techniques ? caching, protocol optimization,
compression and traffic management.
Caching data locally at remote locations
requires fewer trips across the WAN.
Protocol optimization reduces latency by
addressing inefficiencies in protocols, such as
Microsoft's Common Internet File System.
CIFS typically is used in Windows-based filesharing
Network traffic compression helps increase
throughput across WAN links. Meanwhile, traffic
management techniques use quality-of-service
provisions to shape bandwidth and prioritize
traffic on the network.
There is no single approach to WAN optimization.
The Navy, for example, could
improve ship-to-shore connectivity on a variety
of link types by using a combination of optimization
hardware and software to increase
Dan O'Barr, systems administrator at the
Nevada Department of Corrections, said he has
noted a significant improvement in response
time since implementing WAN optimization.
"It's important that the application has a fast
enough response time to make its use interactive,
even to our most remote locations," O'Barr
WAN optimization also can help push green
initiatives. By blending WAN optimization with
fewer, consolidated data centers using virtualization,
an agency can improve performance
while using less power.
Beyond the data center, workforce distribution
is playing a key role in driving WAN optimization.
"Today, our data shows that more than 70 percent of the workforce works outside
of headquarters," Whiteley said.
WAN optimization footprints can address a
variety of computing situations. For example,
WAN optimization devices might be implemented
between two agency data centers to
improve performance in redundant data center
Likewise, devices can be implemented
between data centers and branch offices or
business partners to speed performance and
reduce the number of servers required.
A combination of hardware in the data center
with software on the client side ? which
administrators often can remotely install across
a virtual private network ? can be used to
implement WAN optimization for mobile and
remote workers. Furthermore, some software-only
solutions can be implemented between an
agency's central location and remote
Although WAN optimization has been around
for a while, there are several new trends in the
Wide Area File System implementations formerly
were devoted to addressing inefficiencies
with CIFS and other so-called chatty network
Today, WAFS is considered a subset of the
broader WAN optimization picture known as
WAN Data Services. Most vendors support
WAFS and WDS in their WAN optimization
WDS goes further than WAFS by optimizing
additional protocols, such as Secure Sockets
Layer, HTTP, Extensible Markup Language
and TCP/IP. In addition, caching, compression,
prioritization and optimization are being
applied to other types of data streams, such as
video and audio.
Optimization of SSL and multimedia traffic
are two of the fastest growth trends in WAN
optimization. However, solution providers in
the WAN optimization marketplace support
varying protocols and methods to streamline
network traffic. Contractors should expect
agencies to compare their network use with
Traditionally, WAN optimization has been
achieved via pairs of hardware devices placed at
complementary sites, such as data centers and
branch offices. With the changes in workforce
distribution, agencies are implementing more
hardware/software and software-only WAN
Major carriers such as AT&T Inc. are examining
the possibility of offering WAN optimization
as part of their managed services offerings.
An important consideration before recommending
a WAN optimization solution is the
existing network traffic trends and changing
topologies and workforce demographics.PRODUCT OPTIONS
More than 20 providers of products and services
offer WAN optimization in some way at
prices ranging from $3,000 to more than
$25,000, depending on the scope of features.
The devices include Riverbed Technology's
Steelhead appliances and Interceptor device
and Blue Coat Systems' SG appliances. Cisco
Systems' approach includes its WAE appliances
and WAAS software. Other providers of
optimization tools include Citrix Systems,
Expand Networks, F5 Networks, Juniper
Networks, Packeteer and Silver Peak.
Replify reflects a likely future direction of
WAN optimization: software-only solutions.
The company's Reptor solution takes advantage
of VMware products that are possibly
already running on agency servers to implement
server-side WAN optimization.
In addition, Replify provides companion
client-side software that agencies can implement
via private WAN links or VPNs to
enable WAN optimization for branch offices,
business partners, and remote and mobile
A Canadian agency executed a proof of concept
before moving forward. "We implemented
gear in remote sites to speed e-mail, calendar,
and file and print services," said Tom
Bimson, strategic planning manager at
Service Canada, which gives residents a single
point of access for government services. "User
reaction was very positive, and our network
administrators found the implementation
and ongoing maintenance reasonably painless."
By capturing network statistics and user
experience before and after implementation,
agencies can determine the relative success of
their WAN optimization initiatives.
"We saw dramatic decreases in WAN bandwidth
consumption [and] speedier access to
files and e-mails, and we received sincere
thanks from our proof-of-concept users,"
Bimson said. "Our defined success criteria
were exceeded."Maggie Biggs is a freelance writer.