Large-Scale IP Network Solutions (CCIE Professional Development)

QoS Policy Propagation

Propagation of QoS policy within a network is typically provided in one of three ways:

• Hard state Techniques are applied in circuit or connection-oriented networks. Resource reservations are made prior to or in conjunction with call routing through the network, and the reservations remain until the call or data transfer is terminated. This approach relies on complex signaling techniques for call setup, such as those associated with ATM call routing.

• Soft state Techniques in this process are similar to hard state, except that the reservations must be periodically refreshed. The actual path through the network may change through the duration of the data transfers, which is one of the benefits of soft-state reservation. ...