web services and WAN

In many cases, the roll out of web services must be accompanied with a WAN bandwidth increase to cope with the additional overhead. Unfortunately, there are more challenges as applications are now subjected to the chatty nature of the web (HTTP, DNS, and even FTP). Chatty applications are particularly susceptible to high-latency WAN links, and translate into dismal user performance. Although the flexibility and innovation web services promise are attractive, the implementation costs and poor user performance can make realization of these promises difficult.

Isn't there any other solution than upgrading the WAN bandwidth?

Although web services are based on XML, XML rides on HTTP. Application Acceleration of HTTP improves the user experience for web applications, ensuring their adoption and continued use. Without acceleration, the chatty nature of HTTP can make web applications quite frustrating, as each click signifies a long pause as new pages are fetched. In addition DNS and FTP can be accelerated.

Ref: http://www.expand.com/Solutions/Index.aspx?URL=/Solutions/Web-Applications.aspx