Developer Documentation Library > Interviewer - Server > Architecture > Web Service tier > Image/Template cache > How the image cache is used > How Phone Participants uses the image cache
 
How Phone Participants uses the image cache
The Phone Participants activity is essentially the Web Service for the telephone interviewer. It uses the Image Cache in the same way as mrIWeb, but has fewer configuration options: there is no option for disabling the use of the Image Cache, no way to change the default Image Cache URL; and no option for a global templates and images location.
The only Image Cache configuration option available for Phone Participants is the Local Image Cache URL setting. See How the web service uses the image cache for more information.
The Local Image Cache URL is set in the Phone Participants Web.config file, located by default in c:\InetPub\wwwroot\SPSSMR\CatiInt. The LOCAL_IMAGE_CACHE_URL key defines the location of a local image cache that is used to load templates.
<add key="LOCAL_IMAGE_CACHE_URL" value="http://ServerName/SPSSMR/ImageCache/ImageCache.aspx"/>
Since Phone Participants does not support a global templates and images location, the Image Cache should always be used for multimode surveys.
See also
How the image cache is used