We study the signaling cost factors from two aspects: reservation retry process (or how to recover from reservation blocking), and one-pass signaling. Through simulation, we discover that the reservation retry mechanism used in RSVP is not only process intensive, but also the reservations are slow to converge. We thus explore several design options that can speed up reservation setup and quickly recover from partial reservations. To gain a better understanding of reservation overhead, we have implemented a lightweight one-pass reservation protocol, YESSIR. We show that with careful implementation and by using some of basic hashing techniques to manage flow states, we can achieve good performance with low processing cost. Our YESSIR implementation can support up to 10,000 flow setups per second (or about 300,000 active flows) on a commodity 700 MHz Pentium PC.