Implementing Real-Time Transport Services over an Ossified Network

Real-time applications require a set of transport services not currently provided by widely-deployed transport protocols. Ossification prevents the deployment of novel protocols, restricting solutions to protocols using either TCP or UDP as a substrate. We describe the transport services required by real-time applications. We show that, in the short-term (i.e., while UDP is blocked at current levels), TCP offers a feasible substrate for providing these services. Over the longer term, protocols using UDP may reduce the number of networks blocking UDP, enabling a shift towards its use as a demultiplexing layer for novel transport protocols.