WWNN and WWPN
In a Fiberchannel network,
each network node has a World Wide Node Number (WWNN). Every network node has one or more World Wide Port Numbers
(WWPN).
Imagine a street where many buildings have a house number. There can be some little houses for one familiy having one entrance as well as a big company having a house number but multiple entrances. In the latter you could drive to "XY corporation, Example Drive 38, Entrance D". 38 is the house number - or the World Wide Node Number. "D" would represent the entrance or the "World Wide Port Number".
The WWPN (World Wide Port Number) is an absolute and unique address - the world wide node address may have many ports assigned to it. Communications take place between WWPNs. Normally, WWPNs may be derived from the WWNN. Look at the following graphic which shows a very easy configuration: (there are some vendors where the WWPN may not be derived from the WWNN of the device, this is a very simple example)
Imagine a street where many buildings have a house number. There can be some little houses for one familiy having one entrance as well as a big company having a house number but multiple entrances. In the latter you could drive to "XY corporation, Example Drive 38, Entrance D". 38 is the house number - or the World Wide Node Number. "D" would represent the entrance or the "World Wide Port Number".
The WWPN (World Wide Port Number) is an absolute and unique address - the world wide node address may have many ports assigned to it. Communications take place between WWPNs. Normally, WWPNs may be derived from the WWNN. Look at the following graphic which shows a very easy configuration: (there are some vendors where the WWPN may not be derived from the WWNN of the device, this is a very simple example)
