Partitions create a virtual pipe within a link for an aggregate traffic class, as opposed to individual flows within a class.
They provide a minimum and maximum bandwidth guarantee.
One of the features of PacketWise partitions is that they do not waste bandwidth. If bandwidth allocated to a class is not used up, it is loaned out to other classes until needed by the allocated class.
Partitions can be static (non-burstable) or burstable up to a pre-determined maximum or up to the entire link.
Use a partition to limit a traffic class and keep it from becoming predatory.
You can also use partitions to protect traffic classes from predators. In fact, you can combine partitions to allocate bandwidth with policies to further shape the flows within the pipe.
Typical examples of partition use:
* "No matter how many sessions are active, make sure that Microsoft Exchange never uses more than 400k on the link, so that there is still room for other applications to work." (Partition of minimum 0k, burstable to 400k)
* "The Accounting department pays for 25% of the cost of the 512k link, the Engineering department pays for the rest. Therefore, we want to make sure that each receives at least the share they are paying for." (Partition for Accounting of 128k, burstable to 512k; partition for Engineering of 384k, burstable to 512k)
* "We have two separate PVCs going out of our router: 64k to Cleveland, 384k to Houston." (Partition for Cleveland using IP subnet range, 64k minimum, 64k maximum; partition for Houston using IP subnet range, 384k minimum, 384k maximum)
For more information about partitions, see the following topics in PacketGuide: