Cisco 10000 Series User Manual

5-2
Cisco 10000 Series Router Quality of Service Configuration Guide
OL-7433-09
Chapter 5 Distributing Bandwidth Between Queues
Bandwidth Distribution Between Queues
The router can commit up to 99 percent of the interface bandwidth to one or more class queues. If you
attempt to attach a policy map to an interface when the sum of the bandwidth assigned to classes is
greater than 99 percent of the available bandwidth, the router logs a warning message and does not
allocate the requested bandwidth to all of the classes. If the policy map is already attached to other
interfaces, it is removed from them.
Bandwidth includes the Layer 2 header, Layer 2 payload, and two bytes of trailer.
• On ATM networks, the bandwidth is cell-based and includes Layer 2 overhead and cell overhead
(for example, cell overhead for SNAP and AAL5, the cell header, the AAL5 trailer, and AAL5
padding).
• On Frame Relay networks with link fragmentation and interleaving (LFI) enabled, bandwidth is
based on fragments with Layer 2 overhead included.
The router converts the specified bandwidth to the nearest multiple of 1/255 (PRE1) or 1/65535 (PRE2)
of the interface speed. Use the show policy-map interface command to display the actual bandwidth.
Feature History for Bandwidth Distribution Between Queues
Interfaces Supporting Bandwidth Distribution
The following describes interface support for bandwidth distribution using the bandwidth command:
Interfaces Supporting the bandwidth Command (Outbound Only)
• Physical
• Multilink PPP and Multilink Frame Relay
• ATM shaped (peak cell rate is specified) unspecified bit rate (UBR) PVCs and point-to-point
subinterfaces
• ATM constant bit rate (CBR) PVCs and point-to-point subinterfaces
• ATM variable bit rate (VBR) PVCs and point-to-point subinterfaces
• Label-controlled ATM (LC-ATM) subinterfaces *
• Frame Relay PVCs, point-to-point subinterfaces, and map classes *
• Ethernet VLANs *
* Requires a specific type of hierarchical policy. For more information, see the Chapter 13, “Defining
QoS for Multiple Policy Levels.”
Cisco IOS Release Description Required PRE
Release 12.0(17)SL This feature was introduced on the PRE1. PRE1
Release 12.2(15)BX This feature was introduced on the PRE2. PRE2
Release 12.2(28)SB This feature was integrated in Cisco IOS
Release
12.2(28)SB for the PRE2.
PRE2
Release 12.2(31)SB2 This feature was introduced on the PRE3. The Distribution
of Remaining Bandwidth Using Ratio feature was also
introduced on the PRE3 only.
PRE2
PRE3

Cisco 10000 Series Specifications

General

Brand	Cisco
Model	10000 Series
Category	Network Router
Language	English