Sometimes called stacked channel but more properly reflected channel.
Lars H: I don't think stacked channel and reflected channel are equivalent concepts. A stacked channel is a channel that is a modification of an existing channel; this can functionally be done using the chan create API, but probably more often something like Trf is used. Conversely a reflected channel does not have to have another channel underneath. Virtual channel would make sense as a collective term for both types of channels not existing as OS channels.