Diameter Articles about
Diameter 		 

Information About

Diameter
  CATEGORIES ABOUT DIAMETER
   
authentication methods
   
internet protocols
   
internet standards
   
APPAREL
BABY
BEAUTY
BOOKS
CAR TOYS
CELL PHONES
DVD'S
ELECTRONICS
GOURMET FOOD
GROCERIES
HEALTH & PERSONAL
HOME & GARDEN
JEWELRY
MUSIC
MUSIC INSTRUMENTS
OFFICE PRODUCTS
SOFTWARE
SPORTING GOODS
TOOLS & HARDWARE
TOYS
VIDEO GAMES
SHOPPING HOME
MORE SHOPPING...



Diameter is an AAA (authentication, Authorization And Accounting) Protocol for applications such as network access or IP mobility. The basic concept is to provide a base protocol that can be extended in order to provide AAA services to new access technologies. Diameter is intended to work in both local and roaming AAA situations.


UPGRADE FROM RADIUS

The name is a pun on the RADIUS protocol, which is the predecessor (a diameter is twice the radius). Diameter is not directly Backwards Compatible , but provides an upgrade path for RADIUS. The main differences are :
  • it uses reliable transport protocols ( TCP or SCTP , not UDP )

  • it uses transport level security ( IPSEC or TLS )

  • it has transition support for RADIUS

  • it has larger address space for AVPs (Attribute Value Pairs) and identifiers (32-bit instead of 8-bit)

  • it is a Peer-to-peer protocol, not Client-server : supports server-initiated messages

  • both stateful and stateless models can be used

  • it has dynamic discovery of peers (using DNS SRV and NAPTR )

  • it has capability negotiation

  • it supports application layer acknowledgements, defines failover methods and statemachines (RFC 3539)

  • it has error notification

  • it has better Roaming support

  • it is easier extended, new commands and attributes can be defined

  • basic support for user-sessions and accounting is built in



PROTOCOL DESCRIPTION

The Diameter Base Protocol is defined by RFC 3588, and defines the minimum requirements for an AAA protocol. ''Diameter Applications'' can extend the base protocol, by adding new commands and/or attributes.


Packet format

0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  { Class "wikitable" style="margin: 0 auto text-align: center
  { Class "wikitable" style="margin: 0 auto text-align: center