Troubleshooting guide

REVIEW DRAFT—CISCO CONFIDENTIAL
1-4
Cisco Wide Area Application Services Configuration Guide
OL-26579-01
Chapter 1 Introduction to Cisco WAAS
Overview of the WAAS Interfaces
• Establishes an optimized connection with the branch WAE. If the data center WAE has optimization
disabled, then an optimized connection will not be established and the traffic passes over the
network unoptimized.
In an AppNav deployment, an AppNav Controller intercepts the traffic in the data center and
distributes it to a WAAS node that establishes an optimized connection with the branch WAE. For
more information on an AppNav deployment, see Chapter 1, “Configuring AppNav.”
6. WAAS optimizes subsequent traffic between the branch WAE and data center WAE for this
connection.
Cisco WAAS does not optimize traffic in the following situations:
• The WAE intercepts non-TCP traffic (such as UDP or ICMP).
• The WAE is overloaded and does not have the resources to optimize the traffic.
• The intercepted traffic matches an optimization or AppNav policy rule that specifies to pass the
traffic through unoptimized.
Note If unoptimized traffic reaches a WAE, the WAE forwards the traffic in pass-through mode without
affecting the performance of the application using the passed-through connection.
Key Services of Cisco WAAS
Cisco WAAS contains the following services that help optimize traffic over your wide area network:
• TFO Optimization, page 1-4
• Compression, page 1-6
• Application-Specific Acceleration, page 1-6
• File Services for Desktop Applications, page 1-8
• WAAS Print Services, page 1-9
• Virtualization, page 1-10
Note WAAS Express devices provide basic optimization and compression services and some application
acceleration.
TFO Optimization
Cisco WAAS uses a variety of transport flow optimization (TFO) features to optimize TCP traffic
intercepted by the WAAS devices. TFO protects communicating clients and servers from negative WAN
conditions, such as bandwidth constraints, packet loss, congestion, and retransmission.
TFO includes the following optimization features:
• Windows Scaling, page 1-5
• TCP Initial Window Size Maximization, page 1-5
• Increased Buffering, page 1-5
• Selective Acknowledgment, page 1-5