Chapter 6. Data Port Configuration
6-2 TSU IQ+ User Manual 61200275L1-1

PORT MAP

The PORT MAP designates which DS0s are assigned to which port.
For example, to pass the channel’s data to a PBX, map the channel
to the DSX-1 port. To pass data to another device (such as a router),
map the channel to the NXport. Set all unassigned channels to
IDLE.

NX PORT

Configure the PHYSICAL LAYER and FRAME RELAY options for the
V.35 Nx56/64 port. Descriptions of the available selections follow.

Physical Layer Options (PHYS LYR OPTS)

Flow Control
This option determines how the TSU IQ+ responds to congestion
during DBU operation.
None
No flow control is used and the TSU IQ+ drops frames during
severe congestion while in DBU operation.
Hardware
The TSU IQ+ varies the DTE TC clock as necessary to relieve
congestion during DBU operation.
FECN/BECN
While in a congested state during DBU operation, frames across the
DBU PVCs have FECN or BECN set depending on the direction.
Frames outbound to the network have FECN set, while frames
inbound to the attached DTE device have BECN set. This method
is useful if the attached DTE devices can respond to congestion
notification.
CTS Option
Set the CTS lead to FORCED ONor FOLLOW RTS.
Forced On
The CTS lead is always on and the RTS lead is ignored.