Troubleshooting guide

REVIEW DRAFT—CISCO CONFIDENTIAL

1-3

Cisco Wide Area Application Services Configuration Guide

OL-26579-01

Chapter 1 Introduction to Cisco WAAS

Benefits of Cisco WAAS

Traffic Optimization Process

Figure 1-1 shows the process that Cisco WAAS follows to optimize application traffic.

Figure 1-1 Traffic Optimization Process

The following steps describe how your WAAS network optimizes a connection between a branch office

client and a destination server:

1. A branch office client attempts to connect to the destination server over the native application port.

2. The WAAS network uses WCCP or PBR to intercept the client request, or if deployed on an inline

WAE, WAAS can intercept the request directly using inline mode. For more information on inline

mode, see the “Using Inline Mode Interception” section on page 1-42.

3. The branch WAE performs the following actions:

• Examines the parameters in the traffic’s TCP headers and then refers to the optimization policies to

determine if the intercepted traffic should be optimized. Information in the TCP header, such as the

source and destination IP address and port, allows the branch WAE to match the traffic to an

optimization policy rule. For a list of predefined policy rules, see Appendix 1, “Predefined

Optimization Policy.”

• If the branch WAE determines that the traffic should be optimized, it adds information to the TCP

header that informs the next WAE in the network path to optimize the traffic.

4. The branch WAE passes along the client request through the network to its original destination

server.

5. The data center WAE performs the following actions:

• Intercepts the traffic going to the destination server.

Poor link utilization TCP optimization features improve network throughput by reducing

the number of TCP errors sent over the WAN and maximizing the

TCP window size that determines the amount of data that a client

can receive at one time.

Packet loss Optimized TCP stack in WAAS overcomes the issues associated

with high packet loss and protects communicating end points from

the state of the WAN.

Table 1-1 Cisco WAAS Solution (continued)

WAN Issue WAAS Solution

WAN

154635