Configuring Quality of Service

Do the following to configure the QoS for the tunnel. The same configuration can be used on both tunnel end points.

To configure DSCP TTL Mode for one of the tunnel end points.

Enter global configuration mode.
```
SLX# configure terminal
SLX (config)# 
```
Use the interface tunnel command to enter interface configuration mode and configure a tunnel. Here we are configuring tunnel with ID 20.
```
device (config)# interface tunnel 22
```
The valid range for tunnel IDs is from 1 through 1024.
Configure the DSCP value.
```
device(config-intf-tunnel-20)# dscp 28
```
Configure the TTL value.
```
device(config-intf-tunnel-20)# ttl 135
```
Configure the QoS mode for this tunnel. Configure this value from either pipe or uniform modes.
```
device(config-intf-tunnel-20)# dscp-ttl-mode pipe
```
Note
The default QoS mode is pipe.

When the DSCP TTL mode is configured as pipe, the DSCP and TTL values that are configured on this tunnel interface are used.

When the DSCP TTL mode is configured as uniform, the DSCP and TTL values are copied from the packet being transported over the tunnel and is used in the tunnel header.

Note

When the DSCP TTL mode is set to pipe and the DSCP and TTL values are not configured within the tunnel, the default DSCP and TTL values are used.

The following is the consolidation of the above configuration steps.

interface tunnel 20 
mode gre ip
source loopback 6
destination 32.32.32.1
router-interface ve 5
ttl 135
dscp 28 
dscp-ttl-mode pipe

The following shows the configuration of a tunnel end point where the DSCP TTL mode is uniform. Here TTL and DSCP configurations are not required.

interface tunnel 20 
mode gre ip
source loopback 6
destination 32.32.32.1
router-interface ve 5
dscp-ttl-mode uniform