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Chapter 21
Configuring ATM Connections
Figure 21-27 VBR.3 Connection, Policing = 3, with Bucket 2 non-Compliant
Connection setup
and compliance status:
VBR.3
Policing = 3
Bkt 1 depth < CDVT(0+1)
Bkt 2 depth > BT + CDVT
CLP=1
Time
interval
variations
CDVT(0+1)
Leaky Bkt 1
ABR Connection Policing
Available Bit Rate (ABR) connections are policed the same as the VBR connections, but in addition use
either the ABR Standard with VS/VD congestion flow control method or the ForeSight option to take
advantage of unused bandwidth when it is available.
UBR Connection Policing
The contract for a unspecified bit rate connection is similar to the ABR connection service for bursty
data. However, UBR traffic is delivered only when there is spare bandwidth in the network.
When a connection is added, a VPI.VCI address is assigned, and UPC parameters are configured for the
connection. For each cell in an ATM stream, the VPI.VCI addresses are verified and each cell is checked
for compliance with the UPC parameters as shown in Figure 21-28.
Leaky Bucket 1
Leaky bucket 1 polices the UBR connection for PCR compliance. When CLP=No (UBR.1), all cells that
are compliant with leaky bucket 1 are applied to the network. However, these cells are treated with low
priority in the network with a percentage utilization default of 1 percent.
Release 9.3.30, Part Number 78-12907-01 Rev. E0, May 2005
5
4
3
2
CLP=0
CLP=1
CLP=0
5
CLP=1
CLP=0
CLP(0) cells
+
compliant with
Leaky Bkt 1
are applied to
Leaky Bkt 2
PCR(0+1)
Leaky Bkt 1
discards
if depth >
CDVT(0+1)
1
CLP=0
3
CLP(1) cells compliant with Leaky Bkt 1, admit to network
CLP=1
4
2
1
CLP=0
CLP=0
BT + CDVT
Leaky Bkt 2
Cisco BPX 8600 Series Installation and Configuration
Traffic Policing Examples
4
CLP=0
CLP=1
Two CLP(0) cells, 1 and 2,
are shown as non-compliant
+
with the BT + CDVT limit of
Leaky Bkt 2. With policing = 3,
the cells are tagged as CLP=1
and admitted to the network.
SCR
2
1
CLP=1
21-51
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Troubleshooting
