soap.wsdl_cache_dir [/temp] # make sure this folder is writeable by php (if using disk cache)
    # otherwise give the web server access to it
    # check what webserver has for user for example _www or www-data
    # Example on MAC:
    # chown -R $(whoami):_www /temp

soap.wsdl_cache_ttl [seconds] # Time To Live, how long it is cached