Example using communication lines

Lines are often shared between processors, and can even be shared between operations. Lines are never allocated by z/OS®, because they are owned by a communication controller, but you might want to ration the number of file transfer jobs, for example. If you have a number of lines from New York to London, with a total capacity of 256 kbaud, you can specify a quantity of 256. If you give a file transfer operation exclusive use of 20 units, for example, that gives the lines a limit of 12 file transfers.

You can protect online and voice systems that use the same lines by giving them a shared allocation of, for example, 50 units each. Because they share units, they do not compete with each other; you can have an unlimited number of operations each sharing 50 units, but this limits the quantity available for file transfers to 206.

Specify the resource like this:
Name
LINES.TO.LONDON
Quantity
256
Used for
B (both planning and action).
On-error action
Free all.
Workstations
Connect to all workstations that can use the lines.
Intervals
Reduce the number available at peak hours, which will keep more transfer jobs out and improve the performance of online systems.