User guide

BSGX4e Business Gateway User Guide 187
Release 01.01 NN47928-102
GoS Configuration
Interface Max Comment
------------------------------------------------------------
eth0 1500000 Office link
Delete GoS Link
NOTE: Before you can delete a GoS link, you must delete all quality groups that
apply to the link. To list the quality groups, enter the command show
quality group.
For example, the following command deletes the GoS link for the WAN interface
eth0:
>
del qos link eth0
*> save
Configuring Quality Groups
This section describes how to configure quality groups. A quality group is the
definition of a GoS treatment, including bandwidth, policing, and GoS class.
Configuration Constraints
 The GoS link must be configured before the quality groups that reference that
link.
 Ten percent of link capacity is always reserved for Best Effort traffic. Thus, no
more than 90% of the maximum link rate can be explicitly committed to other
quality groups. The sum of the committed rates for all other quality groups must
not be greater than 90% of the link rate.
Downgraded and Dropped Packets
Consider the following when configuring GoS quality groups:
 When a quality group specifies committed access rate (CAR) policing, traffic can
be downgraded and discarded, as follows:
n Traffic received between the committed rate and the burst rate is
downgraded; it becomes best effort (BE) traffic.
n Traffic assigned to BE is forwarded only if bandwidth is available. If bandwidth
is not available, the traffic is discarded; thus, the forwarding of downgraded
traffic is not guaranteed.
 Traffic is always discarded if the offered load is out of contract: traffic is not
forwarded if it exceeds what is guaranteed. Traffic received over the committed
rate for a policed quality group or over the burst rate for a CAR quality group is
always discarded.