Diameter Protocol: For AAA and Much More in 4G Networks
What Makes IP Based Network Technology Work
Can you think of a time when people weren’t walking around with their heads down looking at their smart device to check their latest email, Facebook posting or instant message? These IP-based services are skyrocketing in popularity and the smart device that delivers these services is becoming a mass market commodity. These are two of the main drivers for significant investments in network rollouts of 4G such as LTE (Long Term Evolution).
Similar to past generations, 4G networks require secure and efficient provision of Authentication Authorization and Accounting (AAA) services, which is the basis for service administration such as deciding which services a user can access, at what quality-of-service (QoS) and how much to bill them. Since the advent of IP-based technology in a telecommunications network, Diameter protocol has been chosen as the AAA protocol for all fixed and mobile networks. Diameter has the competitive edge over legacy AAA solutions and is a foundation of EPS (Evolved Packet System) – the new core network that supports LTE technology.
The Diameter name is a play on words on its predecessor RADIUS protocol (Remote Authentication Dial-In User Service). Diameter has been embraced by the many standards’ bodies such as the 3GPP and ETSTI as the foundation for all AAA functionalities in next-generation networks (NGN).
Diameter was developed as AAA grew to support additional needs such as policy control, dynamic rules, quality-of-service, bandwidth allocation and new charging schemes. These, and other upgrades in 4G such as real-time functionality for transactions, can only be handled with Diameter protocol.
Some of Diameter protocol’s advantages include:
- Unlimited scalability: Growing a network according to its business policies and while scaling, to prevent network fragmentation.
- Fault-tolerance: Defining the procedures that allow for performance of failover or failback on the network when any of the other node’s services are unavailable. By doing this, Diameter solutions guarantee message delivery.
- Agent support: Clearly defining the responsibilities of all possible Diameter node deployment modes, either as Proxy, Redirect, Relay or Translation Agents.
- Secured communication: Providing an optional secure transmission of Diameter message packets.
- Reliable transmission: Transmitting the Diameter packets over Transmission Control Protocol (TCP) or Stream Control Transmission Protocol (SCTP).
- Capability negotiation: Mandating the exchange of capabilities whenever a connection is established with any peer mode so that the nodes know in advance about the peers before beginning traffic (e.g. what applications, security mechanisms etc).