Verilink 2000 (34-00182) Product Manual - Manual (Page 51)

Configuration Screens 4-17
(D4 to ESF and ESF to D4). Older D4 equipment can be supported with newer
ESF spans. ESF framing allows the user and telco access to the increased
serviceability and information available through the FDL protocols. The choices
are ESF and D4.
DTE Line Code
Selects the line coding for the DTE side of the CSU. The choices are AMI and
B8ZS.
DTE Keep Alive
Selects the action to take place when there is a loss of frame or signal on the
network as shown in Figure 4-14. The choices are as follows.
AIS. Transmit unframed all ones toward the DTE.
ONES. Transmit framed all ones toward the DTE.
LOOP. Activate a payload loopback on the DTE interface.
DTE->NET CRC
This field determines whether received CRC data from the DTE passes to the
network or if a new CRC is generated. The choices are PASS and REGEN.
DTE DSX Level
Specifies the line build out for the DTE output of the unit. The choices
are 0 -110ft, 111-220ft, 221-330ft, 331-440ft, 441-550ft, 551-660ft, and > 660ft.
FDL Pass Through
This field determines whether the ESF FDL passes through the CSU or terminates.
The choices are PASS and TERMINATE.
Framing, CRC, FDL
Tx
Rx
Rx
Tx
NET LOF, AIS to DTE
DTE
Interface
NET
Interface
AIS
Framing, CRC, FDL
Tx
Rx
Rx
Tx
NET LOF, Framed Ones to DTE
DTE
Interface
NET
Interface
F1s
Framing, CRC, FDL
Tx
Rx
Rx
Tx
NET LOF, LLB on DTE
DTE
Interface
NET
Interface
F1s
Figure 4-14 DTE Keep Alive Descriptions