Cisco Systems OL-5375-01 manual Content Expiration Header Setting

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Chapter 5 HTTP Client Requests and Header Settings

HTTP Header Settings

Use the following ASP sample script to set the MIME type and to serve the file that is specified in the #include command:

<%@ Language=JavaScript%> <%

Response.ContentType = "audio/basic";

%><!--#include file="filename.raw" --><% Response.End();%>

Using script to generate the MIME header when playing a sound provides an advantage because you may also include a refresh header to take the phone to a subsequent URL. Usually, you can set the MIME type for pages in any web server by simply performing an association to the .xml or .raw file extension. Your web server documentation should explain how to accomplish this. This action allows you to serve static pages without the need for writing script.

Content Expiration Header Setting

The expiration header can control which URLs are added to the phone URL history. This behavior differs slightly from traditional web browsers but is implemented to perform the same function. Disable the back button functionality to avoid calling a URL twice.

This functionality allows you to make the content of any page that is sent to the phone expire. When a user presses the Exit softkey, the user goes back to the last URL that did not expire when it was loaded. This differs from traditional browsers by not considering the current freshness of the data but the freshness of the data when the URL was requested. This requires you to have a page expire when it is first loaded and to not set a time and date in the future.

The following example shows how to have content on IIS expire by using

Active Server Page (ASP):

<%@ Language=JavaScript %> <%

Response.ContentType = "text/xml"; Response.Expires = -1;

%>

The "Expires" property specifies the number of minutes to wait for the content to expire. Setting this value to -1 subtracts 1 minute from the request time and returns a date and time that have already passed.

 

 

Cisco IP Phone Services Application Development Notes

 

 

 

 

 

 

OL-5375-01

 

 

5-65

 

 

 

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Contents Http Client Requests Http Client Requests and Header SettingsHttp Refresh Setting Http Header SettingsRefresh Display Sample Audio Clips Mime Type and Other Http HeadersContent Expiration Header Setting CiscoIPPhoneDisplay Identifying the Capabilities of IP Phone ClientsCiscoIPPhoneModelName CiscoIPPhoneSDKVersion Accept HeaderMajor version.minor version.maintenance version