Protocol Hierarchies

• The protocol stack is an implementation of a computer networking protocol suite.
•  The terms are often used interchangeably.
•  Strictly speaking, the suite is the definition of the protocols, and the stack is the software implementation of them.
• Individual protocols within a suite are often designed with a single purpose in mind.

• 

Hierarchical protocols is nothing new, but provides an interesting approach to the balance between scalability and performance. 

The most well known service in use today that uses a hierarchical protocol is DNS. 

The purpose of DNS is to translate a human friendly domain name, 

such as www.ietf.org, to its corresponding IP address (in this case 4.17.168.6). 

The DNS architecture consists of the following:

• Root name servers
• Other name servers
• Clients