Connectionless network service clns addressing

NSAP address structure of ISIS
The NSAP address is divided into three parts: the region address is 6 bytes, and the system ID selector is used.
AFI and Idi are similar to the address class in an IP address.
A specific part of hodsp's high-end domain, similar to the host ID in an IP address
NSEL is used to identify a process on the device. It is similar to the Service port number in the IP address. If NSEL is set to 00, it indicates that the device is comfortable. In this case, NSAP is called the Network Real Name body.
The region address is used to identify the routing region, and the system ID is used to identify a node.
All routers in the same region must have the same region and address.
The region address is routed by level2.