QoS Packet Marking

Reference Guide to Implementing Crypto and QoS


As VPNs grow to include data, voice, and video traffic, the different types of traffic need to be handled differently in the network. Quality of service (QoS) and bandwidth management features allow a VPN to deliver high transmission quality for time-sensitive applications such as voice and video. Each packet is tagged to identify the priority and time sensitivity of its payload, and traffic is sorted and routed based on its delivery priority. Cisco VPN solutions support a wide range of QoS features.

This document is designed to serve as a single reference for users who configure Cisco IOS® encryption and QoS features on the same network or set of routers. You will see basic configurations of both input and output QoS policies in the presence of IP Security (IPSec) and generic routing encapsulation (GRE) tunnels. This document helps you to understand the configuration tasks. It also provides information on restrictions and known issues, to ensure optimal performance and successful implementation of enhanced IP services using Cisco routers.



Readers of this document should have knowledge of these topics:

  • IPSec technology

For a more exhaustive document on IPSec, refer to An Introduction to IP Security (IPSec) Encryption.

Components Used

This document is not restricted to specific software and hardware versions.


For more information on document conventions, refer to the Cisco Technical Tips Conventions.

IPSec Protocols

A detailed discussion of the IPSec protocols is beyond the scope of this document. However, an overview is provided in this section. See the Related Information