passive activity-that is, it does not drive process control-and it can tolerate delay. File transfer can also tolerate losses because a reliable protocol such as TCP ensures that any errored or lost data is retransmitted, hence no data is lost. With file transfer, error control can be performed at the endpoints. Two other important applications are interactive computing and information retrieval. With these applications, bandwidth is dependent on the objects being retrieved: If it's text, it's low bandwidth; if it's streaming or interactive video, the experience may not always be satisfactory. Interactive computing and information retrieval are delay sensitive when it comes to downloads, so higher speeds are pre- ferred. Real-time voice is a low-bandwidth application but is extremely delay sensitive. Real-time audio and video require medium, high, and even very high bandwidth, and they are extremely delay sensitive (both end-to-end delay and jit- ter), and the applications work much better if the packets arrive in their original Chapter 5 Data Communications Basics sequence. Multimedia traffic and interactive services require very high bandwidth, and they are also extremely sensitive to end-to-end delay and jitter, perform better if the packets arrive in their original sequence, and are extremely loss sensitive. Anything that is text-based-such as e-mail, transaction processing, file trans- fer, and even the ability to access a database for text-based information-is fairly tolerant of losses. But in real-time traffic-such as voice, audio, or video-losses cause severe degradation in the application. For new generations of networks, the ITU (www.itu.int) suggests that packet loss should not exceed 1%; that's far from the case in today's networks. The public Internet, being a global infrastructure, has a wide range of experiences. In some parts of the world, generally in developing countries, packet losses can surpass 40% during peak hours, while developed nations have an average of approximately 5% during the day. 