Troubleshooting guide

REVIEW DRAFT—CISCO CONFIDENTIAL
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Cisco Wide Area Application Services Configuration Guide
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Chapter 1 Introduction to Cisco WAAS
Overview of the WAAS Interfaces
Cisco WAAS helps enterprises meet the following objectives:
• Provide branch office employees with LAN-like access to information and applications across a
geographically distributed network.
• Migrate application and file servers from branch offices into centrally managed data centers.
• Minimize unnecessary WAN bandwidth consumption through the use of advanced compression
algorithms.
• Virtualize print and other local services to branch office users. Cisco WAAS allows you to configure
a WAE with Windows in a virtual blade so that you do not need to deploy a dedicated system to
provide local services such as Print Services, Active Directory Services, DNS, and DHCP services.
• Improve application performance over the WAN by addressing the following common issues:
– Low data rates (constrained bandwidth)
– Slow delivery of frames (high network latency)
– Higher rates of packet loss (low reliability)
Note A WAAS Express device, which is a Cisco router with WAAS Express functionality enabled, can
interoperate with WAE devices. A WAAS Express device provides basic WAN optimization and some
application optimization but no virtualization. For more information on WAAS Express, see Configuring
WAAS Express.
A virtual WAAS (vWAAS) instance is a virtual WAAS appliance running on a VMware virtual machine
and providing all of the same features as a WAAS appliance. A WAAS Central Manager can manage
WAEs, WAAS Express devices, and vWAAS instances all in the same WAAS network. For more
information on vWAAS, see the Cisco Wide Area Application Services vWAAS Installation and
Configuration Guide.
This section contains the following topics:
• Cisco WAAS Overcomes Common WAN Challenges, page 1-2
• Traffic Optimization Process, page 1-3
Cisco WAAS Overcomes Common WAN Challenges
Table 1-1 describes how Cisco WAAS uses a combination of TCP optimization techniques and
application acceleration features to overcome the most common challenges associated with transporting
traffic over a WAN.
Table 1-1 Cisco WAAS Solution
WAN Issue WAAS Solution
High network latency Intelligent protocol adapters reduce the number of roundtrip
responses common with chatty application protocols.
Constrained bandwidth Data caching provided with the file services feature and data
compression reduce the amount of data sent over the WAN, which
increases data transfer rates. These solutions improve application
response time on congested links by reducing the amount of data
sent across the WAN.