The end-to-end delay of Internet is a fundamental indicator for network performance evaluation and has been becoming a hot issue in network measurements in recent years. There are two kinds of metrics related to the end-to-end latency, i.e., Round Trip Delay and One-way Delay metric. In the paper, we survey the recent progresses on these two types of metrics measurement. Special concerns are on the clock synchronization issue in one-way delay measurement. The problems in deploying end-to-end delay measurement and the timestamping issue are also summarized. The potential new research directions in delay measurement and analysis are discussed.