All you need to make your pages wispr complient is to add the wispr xml in the login.html. We use this and it is working with clients from IPASS, WeRoam, Boingo, Skype and several others.
You can still make use of an external hotspot login page by adding some redirectiung using a post.
Example login.html:
<html xmlns="
http://www.w3.org/1999/xhtml">
<head>
<!--
<?xml version="1.0" encoding="UTF-8"?>
<WISPAccessGatewayParam xmlns:xsi="
http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="
https://YOUR WEB SERVER DNS NAME GOES HERE/WISPAccessGatewayParam.xsd">
<Redirect>
<AccessProcedure>1.0</AccessProcedure>
<AccessLocation>isocc=za,cc=27,ac=12,network=AlwaysOn</AccessLocation>
<LocationName>AlwaysOn:ZA, Other, AlwaysOn Office</LocationName>
<LoginURL>$(link-login)</LoginURL>
<AbortLoginURL>$(link-logout)</AbortLoginURL>
<MessageType>100</MessageType>
<ResponseCode>0</ResponseCode>
</Redirect>
</WISPAccessGatewayParam>
-->
<title>...</title>
</head>
<body>
<form name="redirect" action="" method="post">
<input type="hidden" name="mac" value="$(mac)" />
<input type="hidden" name="hostname" value="$(hostname)" />
<input type="hidden" name="ip" value="$(ip)" />
<input type="hidden" name="user" value="$(user)" />
<input type="hidden" name="link-login" value="$(link-login)" />
<input type="hidden" name="link-orig" value="$(link-orig)" />
<input type="hidden" name="error" value="$(error)" />
</form>
<script language="JavaScript" type="text/javascript">
<!--
document.redirect.action = "YOUR EXTERNAL URL GOES HERE";
document.redirect.submit();
//-->
</script>
</body>
</html>
In Logout.html add the following in the head:
<!--
<?xml version="1.0" encoding="UTF-8"?>
<WISPAccessGatewayParam xmlns:xsi="
http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="
https://YOUR WEB SERVER DNS NAME GOES HERE/WISPAccessGatewayParam.xsd">
<LogoffReply>
<MessageType>130</MessageType>
<ResponseCode>150</ResponseCode>
</LogoffReply>
</WISPAccessGatewayParam>
-->
