It's is about (45-60)min test. And it needs reliable internet connection, it is preferable to use cable internet than wi-fi. It's minimum speed should be 1Mb. You also need quiet and bright room or place to take the test. Overall you can practice the sample test. Btw you can only take the test by PC. You will spend the 1st 5min filling your personal info (You need to have passport since only passport is allowed for Ethiopian test taker). The most important is your internet reliability, if not you may not be able to upload your test at the end.