Cisco WAAS: optimized the Third-Generation Wireless Network

The application of network technology is the focus of our attention, so for the development of the network, we will give us a detailed introduction to the Development of Cisco WAAS technology. With the acceleration of wireless networks and the enhancement of reliability, a feasible alternative is provided for traditional wired WAN solutions, which can serve as the main access link or backup link of Wired services.

The third-generation (3G) wireless solution aims to provide a relatively low cost and high speed for use in areas that are difficult or unable to obtain wired connections. However, the 3G wireless network is not perfect. Its shortcomings include relatively high latency, asymmetric bandwidth restrictions, and packet loss. This document describes how to use Cisco®Wide Area Application Services (WAAS) to overcome some limitations.

This article is based on a series of tests performed to measure the performance characteristics of a 3G wireless connection before and after optimization using Cisco WAAS. Use the data and applications under the actual application to perform each test to describe the overall experience improvement that the user can gain after the optimization and acceleration links. In all circumstances, as long as Cisco WAAS is deployed, the 3G wireless link can achieve substantial performance improvement.

Cisco WAAS Overview

Cisco WAAS is an industry-leading usability solution that combines application acceleration and WAN optimization technologies, solve application implementation dilemmas, promote the integration of distributed servers and storage, improve the performance of existing centralized services, and maintain the performance level of centralized services.

Organizations can use Cisco WAAS to achieve their main IT goals:

● Centralized application and storage in the data center while maintaining performance similar to LAN applications

● Improve the enterprise's throughput, application implementation, and application data to maintain or improve user productivity and efficiency

● Use existing WAN connections more effectively to reduce the high cost required to upgrade WAN bandwidth

● Local hosting of IT services while reducing the overall floor space used by branch office equipment

Test Topology

The simplified network topology used for testing (2) is based on the method from remote site to core site. The left side of the figure is a remote site consisting of a Cisco 2851 Integrated Service Router consisting of two modules: a network module running the Cisco WAAS software (Cisco NME-502 ), and a 3G High-Speed WAN Interface Card (HWIC) that provides wireless connection to the Internet ). Routers and installed modules achieve wireless connection and WAN optimization in a single chassis, reducing the overall connection process. The Microsoft Windows XP client is the final component of the remote site and the endpoint for all measurements.

The right side is the core site that the remote site will connect. The core site uses a Cisco 3845 Integrated Service Router to provide Internet connectivity, but uses a separate Cisco WAAS device, the Cisco WAE-612 wide area application engine, instead of a module. The second Cisco WAE-612 is used as the central manager to provide management services for Cisco NME at core Cisco WAE and remote sites. Finally, Microsoft Windows 2003 Server is used to provide the common Internet File System (CIFS) file service, Microsoft Active Directory, FTP, HTTP, Domain Name System (DNS), and Network Time Protocol (NTP ).

The connection between the two sites is simplified in the figure. The remote site does not have an outgoing physical connection and relies on HWIC to provide a 3G wireless network connection to the service provider. The service provider terminates the wireless components at the gateway and routes the traffic to the WAN interface of the core site router over the Internet. Because the remote site and core site use a dedicated address, a common Routing Encapsulation (GRE) tunnel is established between the two routers to encapsulate the traffic flowing through the Internet.

The traffic from the client to the remote router uses the Web cache traffic Protocol version 2nd (WCCPv2) to intercept all TCP traffic and send it to the Cisco WAAS module. The traffic is optimized and then sent to the core router through the WAN link. The core router uses WCCPv2 to intercept the optimized traffic and send it to the Cisco WAE on this side. The core Cisco WAE removes traffic optimization and sends it to the server. The data returned from the server is transmitted in a reverse path.

In real scenarios, security needs to be taken into account, so some types of encryption should be added to the tunnel. This can be performed by the router using IP Security (IPsec) on the GRE interface, or using an external VPN solution between two Cisco WAAS.

Both vrouters run Cisco IOS®Software Release 12.4 (15) T7 and Cisco WAAS software 4.1.1