Шаблон HTTP-запроса:

http://host:port/<domain>/service/call/subsequent

<?xml version='1.0' encoding='latin1'?>
<in xmlns:xs="http://www.w3.org/2001/XMLSchema-instance">
    <request>
        <subsequent conversation_id="06d176f49a2d37c7" digits="3"/>
    </request>
</in>
<?xml version="1.0"?>
<out xmlns:xs="http://www.w3.org/2001/XMLSchema-instance" xs:noNamespaceSchemaLocation="subsequent.xsd">
    <response>
        <ok/>
    </response>
</out>
<?xml version="1.0"?>
<out xmlns:xs="http://www.w3.org/2001/XMLSchema-instance" xs:noNamespaceSchemaLocation="subsequent.xsd">
    <error cmd="subsequent" reason="command_failed" body="no_such_call"/>
</out>
<?xml version="1.0"?>
<out xmlns:xs="http://www.w3.org/2001/XMLSchema-instance" xs:noNamespaceSchemaLocation="subsequent.xsd">
    <error cmd="subsequent" reason="command_failed" body="unsupported_digits_value"/>
</out>