Final answer:
An Internet connection with poor quality despite fast speed and acceptable ping can suffer from excessive jitter and packet loss, resulting in variance in packet timing and missing data packets respectively.
Step-by-step explanation:
An Internet connection can be fast and have an acceptable ping rate but still have poor quality due to excessive jitter and packet loss. When you experience excessive jitter, it means that there's a variance in the time it takes for packets of data to travel from one point on the network to another. This inconsistency can lead to a frustrating experience, especially during real-time communications like video calls or online gaming. Packet loss, on the other hand, occurs when these data packets fail to reach their destination, which can also severely affect the quality of an Internet connection.