To display your company logo on your IP phone, you need a program called gif2cip, which converts a gif image file to a format the IP phone recognizes, called "cip". The cip image is a basic black-and-white format.
You can then create a web page on your web server that will cause a phone to display your logo when the phone calls the web page. If you set this web page as the phone's "idle url", then the phone will display the company logo when it is idle.
This web page describes the XML you would use in the web page to tell the phone to display an image:
http://www.cisco.com/en/US/products/sw/voicesw/ps556/products_programming_reference_guide_chapter09186a00801fb6da.html#wp1033528
There is a book available that describes creating applications for the IP phones. It is a bit old, but it can be a good resource to start with. You can find that book on O'Reilly Network Safari, which has a free 2-week trial (you can read the book online!):
http://safari.oreilly.com/
The title of the book is:
Developing Cisco IP Phone Services: A Cisco AVVID Solution
That book is based on an older version of the IP Phone SDK, but still has good information on getting started.
You may want to join Cisco's Developer Support program and obtain the IP Phone SDK. The SDK provides more information on developing applications for the IP Phones, and has example applications in both ASP and JSP.
This page describes the Cisco Developer Support Program:
http://www.cisco.com/pcgi-bin/dev_support/access_level/product_support
This page describes the IP Phone SDK:
http://www.cisco.com/en/US/products/sw/voicesw/ps556/products_programming_reference_guide_chapter09186a00801fb6dc.html
Below is a sample idle page in ASP (idle.asp). You would replace the contents in the element (Packed Pixel Data) with the output from the gif2cip program, which is a sequence of hexedecimal text data.
<%@ Language=JavaScript %>
<%
Response.ContentType = "text/xml";
Response.Expires = -1;
%>
0
0
133
46
2
Packed Pixel Data
Welcome to AcmeCorp!
