About QoS considerations
We recommend the maximum classes, rules, and sites shown in this table for optimal performance and to avoid delays while changing the QoS configuration.
The QoS bandwidth limits are global across all WAN interfaces and the primary interface. Traffic that passes through the appliance but isn’t destined to the WAN isn’t subject to the QoS bandwidth limit. Examples of traffic that isn’t subject to the bandwidth limits include routing updates, DHCP requests, and default gateways on the WAN-side of the SteelHead that redirect traffic back to other LAN-side subnets.
Appliance model | Recommended maximum configurable root bandwidth (Mbps) | Recommended maximum classes | Recommended maximum rules | Recommended maximum sites |
255-P | 6 | 300 | 300 | 50 |
255-U | 10 | 300 | 300 | 50 |
255-L | 12 | 300 | 300 | 50 |
For the following appliance models, the network services flows and WAN capacity replace the maximum configurable QoS root bandwidth in previous versions.
For the GX 10000, the total number of classes and rules cannot exceed 4,000.
Appliance model | Network services flows | Network services WAN capacity (Mbps) | Recommended maximum classes | Recommended maximum rules | Recommended maximum sites |
5080-B010 | 160,000 | Unrestricted | 3,000 | 3,000 | 500 |
7080-B010 | 160,000 | Unrestricted | 3,000 | 3,000 | 500 |
7080-B020 | 320,000 | Unrestricted | 3,000 | 3,000 | 500 |
7080-B030 | 800,000 | Unrestricted | 3,000 | 3,000 | 500 |
GX 10000 | 768,000 | Unrestricted | 2,000 | 2,000 | 500 |
QoS doesn’t support IPv6 traffic for shaping or application-based classification. If you enable QoS shaping for a specific interface, all IPv6 packets for that interface are classified to the default class. You can mark IPv6 traffic with an IP ToS value. You can also configure appliances to reflect an existing traffic class from the LAN-side to the WAN-side of the appliance.
By default, the setup of optimized connections and the out-of-band control connections aren’t marked with a DSCP value. Existing traffic marked with a DSCP value is classified into the default class. If your existing network provides multiple classes of service based on DSCP values, and you are integrating a SteelHead into your environment, you can use the Global DSCP feature to prevent dropped packets and other undesired effects.