# Configuring ANCP for QoS Adaptive Mode

The system can QoS adjust VLAN and ATM VC downstream rates received from ANCP when you enable QoS adaptive mode by issuing the qos-adaptive-mode command.

When QoS adaptive mode is enabled, ANCP dynamically creates QoS parameter instances associated with the QoS downstream rate application. ANCP also determines the value the system uses when recalculating the QoS shaping rate. The values of the parameter instances track the bandwidth of the local loop that is communicated by ANCP.

Issuing the clear l2c neighbor command removes all QoS parameter instances associated with the neighbor, including those associated with the QoS downstream rate and QoS cell mode applications.

Similarly, issuing the clear l2c discovery-table command without specifying an entry removes all QoS parameter instances associated with the neighbor. Specifying an entry in the table removes the QoS parameter instance associated with that entry.

After clearing ANCP entries or neighbor sessions, the system recreates the QoS parameter instances when QoS adaptive mode is enabled and ANCP learns the rates again.

For more information about the QoS downstream rate application and QoS parameters, see QoS Downstream Rate Application Overview.

clear l2c discovery-table

- Use to clear all entries or a specified entry from the topology discovery table associated with the neighbor.
- Example
  host1#clear l2c discovery-table neighbor ACCESS_NODE_1
- There is no no version.
- See clear l2c discovery-table.

qos-adaptive-mode

- Use to enable the QoS adaptive mode for ANCP.
- QoS adaptive mode enables the system to shape VLAN and ATM VC downstream rates received from ANCP by dynamically creating QoS parameter instances associated with the ANCP (L2C) downstream application.
- Example
  host1(config-l2c)#qos-adaptive-mode
- Use the no version to disable QoS adaptive mode for the system.
- See qos-adaptive-mode.