Why to use Diameter Protocol

Question

Probably a basic question but still want better clarity so some basic question ?
1. What is the Diameter protocol in simple explanation?
2. Why is it used?
3. How can one use it?

Answer 1

Google and this is what I found

Per the ITU, DIAMETER is the successor to RADIUS (twice as good). No, it's not a joke. RADIUS was, and is still used, in many telecommunications networks as the interface to the authorization, authentication and accounting protocol server (typically just called the AAA). The problem with RADIUS is that:

It's built on UDP -- RADIUS packets can just drop off. It was never designed to handle much more than short, attribute/value pairs. While it is extendible, it's limited to vendor-specific attributes (VSAs)

Theses were all wonderful back with Livingston incorporated made the Portmaster terminal/modem server. (Ah, back in the day... I can hear the telebit trailblazers now...) But that was when 19.2Kb UUCP was cool.

DIAMETER aims to address these issues for the modern world. First, it's based on TCP. This addresses the drop-out problem. We now know that packets don't get there "half way". We can also encrypt streams. It's also, courtesy of TCP, capable of having much larger attribute sets (we call them AVPs). Thus, it's much easier to convey value sets beyond the simple key/value pair.

As an example, in DIAMETER< you can do a login request, sending far more than a username/password. You can send the course location for example, telling the AAA where the user is at login (maybe there are geo-location rules for access). And, because we have a more robust, richer language to say things in, the AAA can convey, not only the yes/no, but the rules for a given yes, or the reasons for the no.

http://stackoverflow.com/questions/11502522/what-is-the-diameter-protocol

Comments

To add a bit of market perspective: Diameter has gained popularity in the recent years because 3GPP adopted it as a key control protocol and defined many 'applications' (protocol extensions) for policy control, billing etc. 3G and LTE networks use this protocol.

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Do we have any other use of diametere other then LTE/UMTS??? AAA is the feature required outside of LTE/UMTS, do we have any use case of diameter being used in Non UMTS/LTE scenario.

Answer 2

Diameter grew out of a previous standard, the RADIUS protocol, to cope with the more complex access control mechanisms and increased security required by the current generation of mobile IP devices and wireless networks. RADIUS (Remote Authentication Dial-in User Service) was inadequate to deal with the new requirements. Diameter is built to allow extension when needed.

Diameter Terms and Components
At its heart, the Diameter protocol is about message exchange. Diameter is constructed as a peer-to-peer architecture, where every node can be a client, server or agent. Agents relay messages between clients and servers. A Diameter message is the base unit used to send commands or deliver notifications to other nodes.

AAA in Diameter
Diameter handles authentication and authorization by way of generalized message passing that is customized by the application being used. In this way, Diameter allows individual applications to perform functions applicable to their use. Accounting messages are more well-defined than authentication messages, and are handled as such by the protocol. One important feature is the enforcement of non-duplication of accounting records using session and message IDs.

Answer 3

1. What is the Diameter protocol in simple explanation?
   Used only to do AAA [Authentication Authorization Accounting]

2. Why is it used?
   I guess only these 2 protocols [Radius, Diameter] can be used for AAA.
   But diameter will support Roaming also, and it have multiple communication over peer nodes where Radius does not do this.

3. How can one use it?
   ???? We have treat this is Protocols [TCP/IP etc].