WIRELESS LAN

Wireless LAN



Wireless LAN

Introduction

We have all heard and know that the corporate network must be safe and secure. And even more now with the Sarbanes-Oxley Act, the Gramm-Leach-Bliley Act, and the Health Insurance Portability and Accountability Act (HIPAA) that have their own security requirements(Baker 2002). The initial security solution for wireless LAN relied on WEP (wired equivalent privacy.) WEP used static keys in the encryption process to secure wireless communication.

Discussion

The wireless LAN has become increasingly more popular over the period of time. Applications such as audio, video and voice have become important to users in a network environment. As the need for these real-time applications have increased the handover latency during the movement Of the mobile node (MN) is very crucial. Large number of wireless access points requires centralized Architecture to manage, control and troubleshoot. Control and Provision of Wireless Access Points (CAPWAP) protocol designed by IETF allow Wireless Termination Points (WTP) to be managed Centrally by an access controller (AC). This paper briefly describes the CAPWAP architecture and Proposes a network setup in which the handover latency is reduced during movement of mobile node. In particular it shows if a Generic Routing Encapsulation (GRE) tunnel is produced between the accesses Controllers, the layer 3 handover latency are reduced. The results are obtained by implementing the Protocol in a tested for layer 2 and layer 3 roaming for data and real-time video streaming.

The demand of wireless communication continues to grow at a rapid pace. Many organizations Have opted for wireless networks because of the ease of deployment and extension as compared to A wired network. Wireless communication provides freedom of access to a network at anytime and Anywhere. However it presents many challenges for continuous communication of audio, video And voice applications.

The CAPWAP working group within IETF began its activity with an aim to define standard Solution to the above mentioned problems [2]. In particular the focus of the group is to standardize A protocol to mange centrally access points and provide compatibility between multiple vendors in A large scale environment. Thus a standardized protocol called Control and Provision of Wireless Access Points (CAPWAP) [3] was designed to provide such functions and interoperability Between different vendors allowing mobile users to roam freely.

This paper presents a brief architecture of the CAPWAP protocol and findings from handover Delays associated with it. The protocol is implemented in a tested environment using physical Switches, access controllers, access points and a mobile node. Two different networks are setup to Measure the latency for layer 2 and layer 3 handover. Several tests including echo packets, file Transfer and video streaming are conducted in order to compare the results.

The rest of this paper is organized as follows. The following section highlights the CAPWAP Protocol and its functionalities in terms of IEEE 802.11 standard. In section 3, the handover Process is described. Section 4 presents the performance evaluation.

THE CAPWAP PROTOCOL

Centralized WLAN architecture can simplify the deployment of large scale networks, by enabling ...