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Configuring CBX or GX Logical Ports
Setting Logical Port Attributes
ATM Services Configuration Guide for CBX 3500, CBX 500, GX 550, and B-STDX 9000
1/19/05
3-33
When you finish configuring the ATM fields, proceed to the next section,
“ILMI/OAM Attributes” on page 3-34
.
User NPC
Function
NNI
Enables or disables the Network Parameter Control (NPC)
function for user circuits. You can also enable or disable the
NPC function for individual PVCs. If you want to use the
NPC function on a per-PVC basis, you must enable the
NPC function on the logical port.
Enabled – Enables the NPC function for circuits on this
logical port for all QoS classes, except ABR. Cells that do
not conform to the traffic parameters are dropped or tagged
as they come into the port.
Disabled – (default) All traffic, including non-conforming
traffic, passes in through the port. If you disable the NPC
function on a logical port, quality of service is no longer
guaranteed on the network due to the potential for
increasing the cell loss ratio on network circuits. With NPC
disabled, Lucent recommends that all ATM UNI ports have
UPC enabled. Traffic entering the network should have
traffic shaping performed.
Enabled with ABR – Enables the NPC function for circuits
on this logical port for all QoS classes, including ABR.
For information on NPC traffic parameters, see
“Configuring ATM Traffic Descriptors.”
Control
NPC
Function
NNI
Enables or disables policing on a user port for control
circuits (signaling and ILMI) independent of user traffic.
The default is disabled.
Enable policing to prevent an attached device from
overloading the switch with data on the control circuit. The
switch polices the control circuit to pre-defined default
traffic characteristics (see
). The attached device
typically needs to support per-VC shaping on the control
channels.
Note: If the attached device is another Lucent switch, do
not enable policing since the CBX 500 and GX 550 do not
support per-VC shaping on the control channels.
Table 3-4.
Add Logical Port: ATM Tab Fields (Continued)
Field
Logical Port
Action/Description
Summary of Contents for CBX 3500
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