The Partition_ID is allocated dynamically, at run-time. Each partition connects to a Partition ID Server which is located on the boot server and asks for a free Partition_ID. The advantage of this approach is that it supports easily client / server solution (client partitions may be duplicated, they will obtain different Partition Ids). There is no need to recompile or relink all the partitions when a new partition is added to the system. The Partition_ID is not tied in any way to a specific protocol or to a specific location.