Circuit-based Transport Services

Description: The Circuit-based Transport Services provide the transport of data channels between two points, multiplexed over a transmission line (leased line, or digital trunk line) using Time Division Multiplexing (TDM). Channels can carry raw synchronous data which is framed to fit into the channelized structure of the transmission line. Trunk lines can be switched at intermediate points. In these services switching is performed on a per-channel basis. The services’ “unit” is the channel within the digital trunk line, and each channel carries a framed synchronous data stream (voice or data). Circuit-based Transport Services can be native, or emulated over higher layer protocols (e.g. IP or ATM). Circuit-based Transport Services service classes (and various support protocols within) are * Native Circuit-based Transport Services – ISDN PRI, and TDM (E1,E3, etc.); and * Circuit Emulation Services – ISDN PRI over IP, TDM over IP, and E3 over ATM.

The following mandatory standards are recommended for this taxonomy node: