Configuring the WSM using Device Manager

Data pacing

Data pacing keeps individual traffic flows under control. It is based on the concept of a virtual clock and theoretical departure times (TDT). The actual calculation of the TDT is based initially on the soft limit rate. The soft limit, also called Best Effort, can be thought of as a target limit for the ISP's customer. If bandwidth is available and the classification queue is not being filled at a rate greater than the soft limit, the TDT will be met for both incoming frames and outgoing frames and no borrowing or bandwidth limitation will be necessary.

If the data is arriving more quickly than it can be transmitted at the soft limit and sufficient bandwidth is still available, the rate is adjusted upwards based on the depth of the queue, until either the rate is fast enough to reduce the queue depth or the hard limit is reached.

If the data cannot be transmitted at the soft limit, then the rate is adjusted downward until the data can be transmitted or the committed information rate (CIR) is hit. If the CIR is overcommitted among all the contracts configured for the WSM, graceful degradation will reduce each CIR until the total bandwidth allocated fits within the total bandwidth available.

Each BWM contract is assigned a bandwidth policy index and (optionally) a name. Contracts can be enabled and disabled. For frames qualifying for multiple classifications, precedence of contracts is also specified per contract. If no precedence is specified, the default order is used.

When both filter Types-Of-Service (TOS) and BWM TOS are applied, BWM TOS has precedence.
BWM configurations will optionally be synchronized during VRRP synchronization except the port contracts and VLAN contracts, which will not be synchronized.