An upper bound delay for the virtual-clock service discipline

Proves that a connection composed of virtual-clock servers provides an upper bound on delay for leaky bucket constrained sessions, i.e., sessions conforming to a token bucket filter. This upper bound on delay is calculated, and it is the same upper bound on delay given by PGPS. The authors also prove that leaky bucket constrained sessions are the only type of sessions for which an upper bound on delay can be provided by servers with an upper bound on link capacity