The previous version of the TFTP specification, RFC 783, included the following statement:

All packets other than those used for termination are acknowledged individually unless a timeout occurs.

The RFC 1350 specification revises this to say:

All packets other than duplicate ACK’s and those used for termination are acknowledged unless a timeout occurs.

The change was made to fix a problem referred to as the “Sorcerer’s Apprentice.”

Deduce and explain the problem.