下列常量由此扩展定义，且仅在此扩展编译入 PHP 或在运行时动态载入时可用。
GUPNP_TYPE_BOOLEAN
(integer)
GUPNP_TYPE_INT
(integer)
GUPNP_TYPE_LONG
(integer)
GUPNP_TYPE_DOUBLE
(integer)
GUPNP_TYPE_FLOAT
(integer)
GUPNP_TYPE_STRING
(integer)
GUPNP_SIGNAL_DEVICE_PROXY_AVAILABLE
(integer)
GUPNP_SIGNAL_SERVICE_PROXY_AVAILABLE
(integer)
GUPNP_SIGNAL_ACTION_INVOKED
(integer)
GUPNP_SIGNAL_NOTIFY_FAILED
(integer)
GUPNP_SIGNAL_SUBSCRIPTION_LOST
(integer)
GUPNP_CONTROL_ERROR_INVALID_ACTION
(integer)
GUPNP_CONTROL_ERROR_INVALID_ARGS
(integer)
GUPNP_CONTROL_ERROR_OUT_OF_SYNC
(integer)
GUPNP_CONTROL_ERROR_ACTION_FAILED
(integer)