Jitter transfer requirements are specified in terms of jitter templates, which cover a specified gain/frequency region. Jitter transfer requirements are intended to ensure that clock recovery circuits and desynchronizer phase smoothing circuits adequately attenuate jitter. If the relationship between the jitter appearing at the input and output ports of a digital equipment can be described in terms of a linear process (A process which is both additive and homogeneous), then a narrowband measurement will characterize its jitter transfer performance and the term “jitter transfer function” is used.