Solutions — Literature
alt="Resonate"> alt="Resonate">By 2005, the number of wireless subscribers will break the one billion mark and a "substantial portion of the phones sold that year will have multimedia capabilities." These multimedia capabilities include the ability to retrieve email and to push and pull information from the Internet. Given the strict requirements for formatting content and bandwidth restrictions for a tiny cell phone or Personal Digital Assistants (PDAs), it becomes clear how important it is for companies to know who is entering their site via a small wireless device and who is using a normal desktop browser.
This application note provides a brief background on wireless technology and the role of Resonate Central Dispatch™ in supporting wireless requests.
The Wireless Application Protocol (WAP) is emerging as the standard transport for Web services being developed and delivered for wireless devices (e.g. cell phones, pagers, PDAs, etc.) According to Phone.com, over 75% of the world's handset manufacturers have already committed to shipping WAP-enabled handheld devices by the end of 2000. By having all handsets designed to support this industry standard protocol, WAP is poised to become the ubiquitous mechanism for wireless communication.
WAP specifies both the protocol and application it uses one of two transports in sending wireless messages: UDP/IP and WDP.
The WAP specification defines the usage of a "WAP Gateway" Web proxy as the core means for connecting wireless devices. A WAP Gateway includes the following:
An example of a WAP gateway is shown below.
Thus, requests from standard WAP devices communicate to WAP Gateways, hosted by the telecommunications carriers (such as Sprint and Worldcom) and convert the WAP request to a standard HTTP request. By the time the request arrives at the particular Web site, it looks like any other request. Companies developing Web services for both browser users and wireless clients are challenged to differentiate this incoming traffic.
Central Dispatch leverages its Data Stream Processing technology to provide an out-of-the-box solution that allows companies to distinguish incoming wireless traffic from other traffic. As a result, wireless requests can be intelligently routed to different resources for optimum performance. This enables companies to maintain a single, unified access point for their services, such as through their www.company.com hostname, without the need for separate hostnames for wireless content such as www.wirelesscompany.com.
Central Dispatch does this through the TCP Data Stream Processing functionality and by creating custom scheduling rules based on browser type. Central Dispatch includes pre-set rules for wireless applications which are easily tailored to a customer's environment. Using binary expressions that search for unique wireless browser-types in the HTTP header, Central Dispatch can now identify incoming wireless users and route them accordingly. This is critical, given the very specific interface formatting and bandwidth restrictions on wireless clients.
It is important to note the WAP supported transport protocols User Datagram Protocol (UDP/IP) and Wireless Datagram Protocol (WDP). WDP is a customized variation of the standard UDP/IP protocol. Central Dispatch does not currently load-balance these WAP protocols because they are UDP, not TCP based. A forthcoming release of Resonate Central Dispatch will add support for UDP/IP.
For more information on how Resonate can help you guarantee the end-user service levels of business-critical applications while cutting operating costs, contact a sales representative at or 408-545-5535.
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