This BOF is to introduce a new "Packetization Layer Path MTU Discovery Algorithm" and discuss IETF venues that might be used to complete the work. This new algorithm does not rely on ICMP or other messages from the network (so it is not subject to the problems described in RFC2923). Instead it finds the proper MTU by starting with relatively small packets and searching upwards by probing with test packets. Key portions of the algorithm need to be implemented in the transport layer. In particular any lost probes should not be treated as congestion signals. For this reason, it can be argued that this work belongs in the TSV area. Many of the unresolved design issues pertain to the efficient use of shared state between concurrent and successive connections to the same destination. The complexities of the this aspect of the algorithm are due to the huge technological breadth and subtleties of the delivery semantics associated with the network and lower layers. For this reason, it can be argued that this work belongs in the INT area.