Which one of the following algorithm is not used for congestion control?

Among the common algorithms used for congestion control in networking, the options often include:

1. TCP Tahoe
2. TCP Reno
3. TCP NewReno
4. Random Early Detection (RED)
5. Explicit Congestion Notification (ECN)

Without a specific list provided in your question to select from, the above are all examples of mechanisms or algorithms that are indeed used for congestion control in networks, mainly within the context of TCP/IP networking. Congestion control algorithms are essential for managing the amount of data that can be sent over the network without overwhelming it, thus preventing packet loss and ensuring data is transmitted efficiently.

If the question implies providing an option that is NOT used for congestion control, then without specific options listed, it’s critical to note commonly discussed algorithms or mechanisms in computer networking related to congestion control are indeed designed for this purpose. Other algorithms or mechanisms outside the scope of network congestion management, such as sorting algorithms (e.g., QuickSort, MergeSort) or encryption algorithms (e.g., RSA, AES), are clearly not used for congestion control.

So, for an accurate answer, I would need the specific options you’re considering. Without that, it’s challenging to pinpoint an algorithm not used for congestion control among a general set of algorithms or mechanisms.