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The following sections provide an overview of the Design Studio application and the Cisco Content Transformation Engine (CTE) Series:
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Note Throughout this publication, the Cisco CTE Series is referred to as the CTE. |
The CTE Design Studio application creates transformation instructions that convert large-screen web applications into a format appropriate for devices with microbrowser screens. Design Studio supports a wide variety of mobile and IP phones and wireless devices, including Personal Digital Assistants (PDAs) such as Palm, Pocket PC, and Research in Motion (RIM) devices. The devices supported in your version of Design Studio and the CTE vary based on your product license.
The real-time conversion of web applications and content does the following:
Typically, microbrowsers are constrained by display size, data input features, and download time. You can leverage applications developed for PC access by indicating in Design Studio how you want the application to appear when delivered to small-screen devices. Design Studio creates content transformation instructions, referred to as transformation rules, based on your decisions.
Depending on the applications that you want to transform and the devices that you want to support, you can choose to create transformation rules for all or just a few of a website's pages. The CTE is an appliance that handles requests for web pages from devices and interprets the transformation rules to convert HTML/XML pages into device-compatible formats. The CTE handles web pages as noted in Table 1-1.
Table 1-1 How the CTE Handles Applications and Web Pages
Design Studio simplifies the task of transforming applications as follows:
CTE XHTML extensions also enable you to specify content transformations in your source HTML files. For more information, see the "Specifying Transformation Rules in HTML Files" section.
Design Studio also includes the ScreenTop editor, which enables you to customize portal pages for phone users. The CTE has a default ScreenTop that you can customize for your site.
The CTE appliance uses rules uploaded from Design Studio to fulfill requests from devices. Figure 1-1 shows the path for a user request for application content in an IP phone enterprise.
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Note The numbers in Figure 1-1 refer to the following process. |
The path a request takes is as follows:
1. An IP phone user requests application content. The IP phone PBX transmits the request to a server load balancer.
2. The server load balancer that receives the request evaluates the request header. The server load balancer directs requests from IP phones to the CTE.
3. The CTE terminates the request and then, acting as a proxy, sends a request to the server load balancer for the application content.
4. When the CTE receives the application content, it uses the rules in the configuration file to transform the content. It also uses the DDF to determine how to handle content for the particular device.
5. The CTE sends the transformed content to the server load balancer for forwarding to the IP phone.
Figure 1-2 shows the path for a user request for application content in an enterprise that services requests from wireless users.
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Note The numbers in Figure 1-2 refer to the following process. |
The path a request takes is as follows:
1. A user requests a URL. A wireless carrier transmits the request to a communications tower, through the Wireless Application Protocol (WAP) carrier gateway, and to the Internet.
2. The server load balancer that receives the request evaluates the request header. The server load balancer directs HTML/XML requests to the application server farm and directs requests from devices to the CTE.
3. The CTE terminates the request and then, acting as a proxy, sends a request to the server load balancer for the application content.
4. When the CTE receives the content, it uses the rules in the configuration file to transform the content. It also uses the DDF to determine how to handle content for the particular device.
5. The CTE sends the transformed content to the server load balancer for forwarding to the device.
The CTE and Design Studio support the formats most commonly used for websites and microbrowser devices.
Website content in the following formats is supported:
The CTE and Design Studio support web pages that use any standard encoding; they transcode web pages to the formats required by supported devices: UTF-8, 7-bit ASCII, and Shift_JIS encoding.
Microbrowsers do not support all content types. Thus, the CTE does not transform the following:
The CTE passes that content to a device without transforming it.
Table 1-2 lists the destination devices supported by the CTE.
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| 1 The DDF Editor contains user agents for the latest device set. |
Design Studio enables you to create transformations for the devices listed in Table 1-2. The base model of the CTE supports the IP phone protocol, enabling multiple, simultaneous transformations from IP phone users. In addition, the base model of the CTE supports one connection at a time for each of the other supported protocols. This feature enables you to test transformations on any CTE, even if you have not paid for support of a particular protocol. To add support for additional protocols, you must purchase license keys.
Most microbrowsers are constrained by display size, navigation, and download time, as described in the following sections. Consider these factors as you choose content for delivery to devices. For information on issues specific to IP phones, go to the Design Studio Help menu and choose Device Help.
Web pages are typically optimized for a 800 x 600 screen resolution; they display reasonably at a 640 x 480 resolution. While some microbrowser devices have a 640 x 320 screen resolution, many devices have a much more limited display size. The amount of web content that you select for display on a device impacts the usability of the content.
A well-designed website uses few clicks to access important content. That same design may not work well on some devices; two or three clicks might be inconvenient to a microbrowser user.
When the page to be served to a device exceeds the amount of text that can display in the microbrowser, the CTE breaks up the page into chunks, serves the first chunk, waits for a request to serve the next chunk, serves the second chunk, and so on.
Large amounts of text take longer to download and require the user to issue requests for the next "page" of content. Depending on the device, the user may request the continuation of a page by spinning a trackwheel, pressing a key, or selecting a button.
For examples of web applications that are transformed, use a microbrowser device to access http://www.screentop.com. This website is a portal to a variety of applications that provide information on such topics as news, stock quotes, weather, white pages, and corporate information. Compare the web page from the originating website to the page delivered by screentop.com to see how the application has been transformed for devices.
Posted: Mon Aug 18 17:50:41 PDT 2003
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