Many symptoms that are seen here can be indications of several types of problems. For example, a packet can be retransmitted because of an error that caused the packet to be lost, or because of bad network conditions (low bandwidth or high delay) that caused the packet not to arrive on time. It can also be because of a non-responsive server or client. The expert info system will give you the symptom. How to solve the problem? We will learn later in this book.