Prerequisites For Dynamic Bandwidth Selection; Restrictions And Limitations For Dynamic Bandwidth Selection - Cisco 10000 Series Configuration Manual

Applying Traffic Shaping Parameters Using RADIUS Profiles

Prerequisites for Dynamic Bandwidth Selection

To download a service policy to a VC dynamically (through RADIUS), you must first enable dynamic
bandwidth selection on the VC by using the dbs enable command. Otherwise, the input and output
policy map that is pulled from RADIUS is not applied on the VC.
For example, when using the atm:vc-qos-policy-out and atm:vc-qos-policy-in RADIUS attributes, first
enable dynamic bandwidth selection as shown in the following sample configuration:
vc-class atm 416k
interface ATM 5/0/0.1 multipoint
The input and output policy map is then applied to the PVC 1/101 as shown in the following sample
debug output:
Nov 25 09:49:23.244: Service policy input Ingress policy output Egress applied on 1/101
Nov 25 09:49:23.244: %c10k_atm_modify_vc_policy(ATM5/0/0): 1/101, vcd 1
Nov 25 09:49:23:244: %c10k_atm_modify_vc_policy(ATM5/0/0): Service policy output Egress
applied on 1/101, vcd 1
Nov 25 09:49:23:252: %c10k_atm_modify_vc_policy(ATM5/0/0): Service policy input Ingress
applied on 1/101, vcd 1

Restrictions and Limitations for Dynamic Bandwidth Selection

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Cisco 10000 Series Router Quality of Service Configuration Guide
17-8
vbr-nrt 416 416
dbs enable
create on-demand
idle-timeout 86400
atm pppatm passive
range pvc 1/101 1/180
class-range 416k
encapsulation aal5mux ppp Virtual-Template1
queue-depth 24 20
Dynamic bandwidth selection (DBS) applies the dynamically updated bandwidth to the ATM VC or
permanent VC (PVC). DBS does not support applying the bandwidth to individual sessions.
The Cisco 10000 series router supports DBS for only ATM interface protocols, such as PPPoA and
PPPoEoA. The router does not support DBS for PPPoE natively over Ethernet or over VLAN.
DBS does not support switched virtual circuits (SVCs).
DBS does not allow all QoS class of service category changes due to segmentation and reassembly
(SAR) firmware limitations. For example, if you have VBR-nrt VCs configured, you can modify the
VCs' shaping parameters (PCR and SCR) using DBS, but you cannot change VBR VCs to shaped
UBR VCs by downloading only the PCR from RADIUS. This behavior also applies to shaped UBR
VCs. Currently, you can change the ATM VC traffic class only by using the modular QoS command
line interface (CLI). For more information, see the
page 17-7.
DBS does not allow unspecified bit rate (UBR) unshaped transitions. The Cisco 10000 series router
does not allow all transitions to and from UBR unshaped PVCs. An unshaped UBR PVC is a PVC
that does not have a rate specified or the rate specified is greater than or equal to the actual
bandwidth. In pxf queuing mode, the router treats all UBRs as unshaped. UBR unshaped is not a
unique service category, but rather a pseudo service category based on the local or RADIUS user
configuration.
Chapter 17 Configuring Dynamic Subscriber Services
"Service Category Transitions" section on
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