Build the label for one of a transfer's parallel data channels.
Labels follow the scheme rtcforge-ft-<transferId>-<index>, letting the receiver route an incoming channel to the correct transfer and lane.
rtcforge-ft-<transferId>-<index>
Id of the transfer the channel belongs to.
Zero-based index of the parallel channel within the transfer.
The data-channel label.
Build the label for one of a transfer's parallel data channels.
Labels follow the scheme
rtcforge-ft-<transferId>-<index>, letting the receiver route an incoming channel to the correct transfer and lane.