This section describes how QoS technology can dramatically improve ERP network performance and why IPHighway's OPS is the best solution for helping companies reap the full benefits of costly ERP implementations. In earlier applications that relied on two-tiers, clients stored most application logic and transmitted cumbersome SQL transactions directly to the database server. In today's ERP systems, middleware application servers store the application logic. By using thin clients teamed with an intelligent application server to communicate with the back-end DBMS, fewer database connections are needed and SQL transactions can be communicated in a more efficient form, so overall network traffic is reduced. For example, in order to minimize the bandwidth needed to process ERP transactions, some organizations have tried using Citrix WinFrame servers to manage groups of thin terminal-like Windows clients.
Less bandwidth is required because the application runs entirely on the server.
Only keyboard entries, mouse clicks, and display updates traverse the network between the WinFrame client and server. While these Citrix configurations can reduce network bandwidth requirements, they are extremely delay-sensitive since every user interaction requires communicating with the Citrix server. For example, just scrolling through the displayed data can be quite disorienting unless the round trip delay time between the client and the Citrix server is kept very low. If network latency rises above 300 milliseconds, the slow response time causes the cursor and the display to become unsynchronized. Although an ERP application might require an average of only 25 Kbps per client, a WAN link provisioned with 256K might only be able to support a few ERP application users if it is being shared with other network traffic such as voice or e-mail transmissions.