application note HP Pr ocurve Switches & Hubs LAN Power: HP Web QoS with HP ProCurve Switches The amount of web traffic in networks is increasing dramatically as more businesses are using the web to provide customers with information about their products and services. As e-commerce becomes more accepted and trusted in the marketplace, there will be even more demands placed on the web servers and on the networks to provide the information and complete the transactions in a timely manner. A common first step is to prioritize e-commerce traffic over Web surfing traffic. However an ideal solution is to prioritize users currently making purchases or with a past purchasing history over those who are browsing the catalog especially when resources are limited. In order to achieve this ideal solution, the bandwidth problem needs to be solved in both web servers and in networks. Hewlett- Packard now has a solution that addresses both of these areas by using HP WebQoS on the servers along with HP ProCurve Switches in the LAN. This application note describes how HP WebQoS and HP ProCurve Switches work together to provide a method of prioritization for different classes of web server traffic. Traffic identified as higher priority receives preferential treatment both within the web server and also in the network. This results in faster response times for users and greater assurance of connectivity between web clients and servers. What is WebQoS? HP WebQoS is a web server-based technology which offers e-commerce sites and service providers the ability to stabilize Web service levels, optimize the use of server and network resources, and prioritize users and applications for their e-commerce transactions. How WebQoS Classifies and Prioritizes Traffic Improving web performance begins with the web server. With WebQoS running in a server, traffic is classified according to several user-configured rules. These rules can be configured according to any of the following methods of classification: Source IP address Destination IP address Destination port Type of Service (ToS) bit settings within the network packet headers URL document path Virtual server name When multiple rules apply to the same packet, the rule that provides the highest level of prioritization will be used. After the HP WebQoS software classifies and prioritizes the requests, they are processed in order of their priority. Less W ork, Mor e Network
Request Queue Control High Stream of incoming requests Requests are handled as soon as they are received so that high priority requests can be quickly identified and processed. Classification, Session Management, Admission Control Med Low WebQoS Priority Queues Queue Processor Web Server Classifying and Prioritizing in the WebQoS Server Queue Processing Policies When the server responds to the request (e.g. downloading a web page to the client), the Precedence value in the IP protocol header can be optionally set for the outbound response. This provides information to network devices such as routers and switches on how to process these packets relative to other traffic in the network. HP ProCurve Switches are an example of devices that can utilize the ToS/IP Precedence information to improve network performance. How HP ProCurve Switches Use ToS/IP Precedence The deployment of ToS/IP Precedence networks is limited and without the means to enforce preferential treatment in the network, the ability of a server to classify traffic with the IP precedence field provides little benefit. Fortunately, HP ProCurve switches can help with both providing differentiation and by classifying data. These switches use multiple outbound port queues to transmit high priority traffic before lower priority traffic sharing the same outbound port. Also, HP ProCurve switches can mark 802.1p/Q tags in packets based on the ToS/IP Precedence settings. This enables downstream network devices that cannot process ToS/IP Precedence, but do understand 802.1p/Q tagging, to process the traffic in priority order. Performance Across the Entire Network By working together, HP WebQoS and HP ProCurve switches provide classification and prioritization in both the web server and the network. When a WebQoS server sets the IP Precedence value in a packet, devices across the entire network can use the information. The HP ProCurve switches use the TOS/IP Precedence value to differentiate services in the LAN. Likewise, routers use the precedence value to differentiate services across the WAN. Additionally, when 802.1p/Q tagging is configured in the LAN, HP ProCurve switches extend the benefits of prioritization to all 802.1p/Q capable devices in the LAN. 2
HP ProCurve Switches IP-TOS Precedence Setting Differentiate traffic classes end-to-end 802.1p Priority Mapping Differentiate traffic classes in the LAN Router 802.1p 802.1p TOS/IP Precedence Internet Intranet Extranet Router HP ProCurve Switches Performance Across the Entire Network Web QoS Server Complex Configuring HP WebQoS to work with HP ProCurve Switches The following provides specific steps for configuring HP WebQoS to work with HP ProCurve switches. I. Set up WebQoS on your web and/or application servers: 1. Modify /etc/opt/webqos/net_tos.conf from the command line before starting WebQoS. 2. In /etc/opt/webqos/net_tos.conf: 2.1. Change the IN_TOS flag to TRUE if you want WebQoS to use TOS for one of the classifying criteria for incoming requests. 2.2. Change the expected value ranges for each user class. Example settings for inbound TOS value mappings: HP WebQoS TOS Values Range 0x80 0xff HI 0x40 0x7f MED 0x00 0x3f LOW HP WebQoS User Class 2.3. Change the OUT_TOS flag to TRUE so WebQoS will set TOS values for outgoing response back to the client. 2.4. Change the expected value for each user class. 3
Example settings for Outbound TOS value mappings: HP WebQoS User Class HI MED LOW HP WebQoS TOS Values Range 0xe0 0x60 0x00 3. Do one of the following: If you have not run the WebQoS setup script, use this command to do so now: /opt/webqos/install/setup If you already have run the WebQoS setup script, stop and re-start the web server, eg: /opt/ns-enterprise36/https-default/stop /opt/ns-enterprise36/https-default/start II. Managing WebQoS from the Management User Interface: Do one of the following: If you have not configured WebQoS from the Management User Interface, see "Configuring WebQoS from the Management User Interface" in Chapter 3 in Installing and Configuring HP WebQoS manual. If you have already configured the WebQoS from the Management User Interface, do the following: 2.1. Go to the Edit Site Configuration window. 2.2. In the Edit Site Configuration window, click on the User Classes tab. 2.3. In the Edit Site Configuration window, click on the Add button. 2.4. In the Add User Classifications window, click on the Classification Type pull-down menu, then select The network sets the user class. 2.5. In the Add User Classifications window, click on OK button. 2.6. In the Edit Site Configuration window, click on the OK button. For complete information on configuring WebQoS on HP servers, see the manual titled Installing and Configuring HP WebQoS. More information on HP WebQos can be found at the HP WebQoS web site at http://www.hp.com/go/webqos. Configuring HP ProCurve Switches To Support HP WebQoS: This section lists the steps for configuring HP ProCurve switches to use the ToS/IP Precedence information in the network traffic to provide preferential treatment to high priority traffic. All HP ProCurve switches that are running OS version C.07.01 or higher can process the ToS/IP Precedence values and prioritize accordingly. There are three methods to configure ToS/IP Precedence prioritization on HP ProCurve Switches: 1. Configure via console or telnet. 1.1. From the main menu select Switch Configuration. 1.2. Select Advanced Features. 1.3. Select Class of Service. 4
1.4. Select Type of Service. 1.5. Select Edit. 1.6. Use the space bar to toggle Type of Service mode to IP Precedence. 1.7. Press the Enter key. 1.8. Select Save. 2. Configure via browser: 2.1. Click on the Configuration tab. 2.2. Click on the Class of Service button. 2.3. Click on the Type of Service button. 2.4. Use the pull-down menu to select IP Precedence. 2.5. Click the Apply Changes button. 3. Configure via TopTools for Hubs & Switches to configure all HP ProCurve switches in the network at once: 3.1. Click on the Policies tab. 3.2. Select Quality of Service. 3.3. Select IP TOS. 3.4. Select IP Precedence. 3.5. Click on Apply. By enabling the IP Precedence feature of Class of Service on the HP ProCurve Switches, the TOS values set by the HP WebQoS server will be mapped to 802.1p priority values by the switches based on the following mappings: HP WebQoS TOS Values Range Corresponding 802.1p Priority 0xe0 0xff 7 0xc0 0xdf 6 0xa0 0xbf 5 0x80 0x9f 4 0x60 0x7f 3 0x40 0x5f 0 0x20 0x3f 2 0x00 0x1f 1 For more details and complete information on configuring HP ProCurve Switches, see the following manuals (shipped with HP ProCurve switch products and also available on the ProCurve web site at http://www.hp.com/go/procurve): The Management and Configuration Guide for the switches you are configuring. Software Update C.7.XX Release Notes for the HP ProCurve Switch 1600M, 2424M, 4000M, and 8000M. 5
Technical information subject to change without notice. All brand and product names are trademarks of their respective companies. All rights reserved. Reproduction, adaptation, or translation without prior written permission is prohibited except as allowed under the copyright laws. Copyright 1999, Hewlett-Packard Company Produced in USA Rev. 1 8/99 6