Description: Point in network where last loopback was performed.

Meaning for t1 CSU/DSU: dtePayload - local DSU loopback. The configured 'fractions' of the DS1 signal is looped back as the receive signal. Used to verify operation of DSU portion of local CSU/DSU. dteFull - local CSU loopback. DS1 transmit signal is looped back as the receive signal. Runs at full bandwidth irrespective of fractions configured. Used to verify operation of local CSU/DSU. lineFull - DS1 signal received from the network is transmitted back to the network. Signal is regenerated but not reframed. Loopback performed at the CSU. Used to verify operation of T1 network. linePayload - DS1 signal received from the network is transmitted back to the network. Data is regenerated and reframed with any LCV or CRC errors corrected. Loopback performed at the DSU. Used to verify operation of local CSU/DSU and T1 network. remoteSmartJack - the remote smart jack (telco installed wall socket device used to delineate network between CPE and telco equipment) is used to loopback the DS1 signal. Similar to remoteFull loopback except that the signal is looped at the smart jack before reaching remote CSU/DSU. Used to verify operation of local CSU/DSU and T1 network. remoteFull - remote unit placed in lineFull loopback. Used to verify operation of local CSU/DSU and T1 network. remotePayload - remote unit placed in linePayload loopback Used to verify operation of local CSU/DSU, T1 network, and remote CSU/DSU.

Meaning for switched 56k CSU/DSU: dteFull - local CSU loopback. Transmit signal is looped back as the receive signal at a point close to the physical network interface. Used to verify operation of local CSU/DSU. lineFull - CSU/DSU is split into separate DTE and loop interface sections. Signal received from the network is transmitted back to the network. Data received from DTE is transmitted back to DTE. Used to verify operation of local CSU/DSU and network from remote site. linePayload - Signal received from the network is looped back at the DTE interface and transmitted back to the network. Data received from DTE is ignored. Used to verify operation of local CSU/DSU and network from remote site. remotePayload - Similar to linePayload except that the remote unit is placed into loopback. Used to verify operation of local CSU/DSU, T1 network, and remote CSU/DSU.