Beta Draft Confidential
Configuring ATM Over MPLS Gateway Solution on CBX 3500
Configuring a Layer 2 Tunnel Over MPLS Core Network
ATM Services Configuration Guide for CBX 3500, CBX 500, GX 550, and B-STDX 9000 1/19/059-55
Continue with “Layer 2 Tunnel VNN Attributes” or “Layer 2 Tunnel PNNI 
Attributes” to configure this Layer 2 tunnel for VNN or PNNI.
Table 9-22. Add Layer 2 Tunnel: ATM Tab Fields
Field Description
• ATM Data rate QOS 1
• ATM Data rate QOS 2
• ATM Data rate QOS 3
• ATM Data rate QOS 4
For each QoS class, select Fixed (default) or 
Dynamic:
• Dynamic – Enables the bandwidth 
allocation to change dynamically 
according to bandwidth demands. 
Dynamic bandwidth allocation pools the 
remaining bandwidth for this logical 
port. This includes bandwidth that has 
not already been allocated to a specific 
queue or assigned to a connection.
• Fixed – Specifies that a percentage of 
bandwidth be reserved for the service 
class. If the network requests a circuit 
that exceeds the fixed value, the circuit 
cannot be created. If all four service 
classes are set to Fixed, all four values 
should equal 100% bandwidth.
If the Layer 2 tunnel type is set to 
Lucent-Proprietary or Atmforum, you can 
select Fixed or Dynamic from the pull-down 
list, then specify the percentage of 
bandwidth in (kbps).
Data Rate (0-max) Enter a value between zero (0) and the 
maximum bandwidth for this tunnel. This 
field is mandatory for dynamic bandwidth 
Layer 2 tunnels. The value in this field may 
not exceed the bandwidth of the PSN tunnel 
set that this Layer 2 tunnel is bound to, or 
the switch will fail CAC.
CLP Copy Check the box to enable CLP copying to the 
EXP on this Layer 2 tunnel. Leave the box 
unchecked (default) if you do not want this 
function enabled.
CW Insert Check the box to enable Control Word 
insertion on this Layer 2 tunnel. Leave the 
box unchecked (default) if you do not want 
this function enabled.