Mobius Diameter Gateway Configuration Setup

Introduction

After successfully installing the Mobius Management Platform (refer to the installation guide for more details), the next step is configuring the Mobius Diameter Gateway. The gateway configuration ensures that your system is ready to handle Diameter protocol-based communication. This guide provides a step-by-step approach to configuring the Mobius Diameter Gateway through the intuitive UI, covering essential parameters such as Diameter settings, Destination setup, Server setup, and Links configuration. 

Diameter Gateway Network Logic

Realm
A realm is an administrative domain in a Diameter network. It is used to identify where a Diameter node belongs and where its requests should be sent. Realms are typically represented as domain names, similar to how web addresses or email domains work. The main purpose of a realm is to group nodes that belong to the same administrative domain or service provider. For example, a mobile network operator might use operator.com as its realm, and all Diameter nodes (e.g., Home Subscriber Server (HSS), Policy and Charging Rules Function (PCRF)) within that operator's domain would belong to that realm.

When a Diameter node sends a message, it includes certain key pieces of information to help with routing:

• Origin-Realm: The realm of the sending node (where the message originates from).
• Destination-Realm: The realm of the receiving node (the intended target of the message).

These AVPs (Attribute-Value Pairs) are included in every Diameter message to indicate where the message is coming from and where it should be routed.

Local Realm Routing
If a message is intended for a node within the same realm, it can be routed internally, based on local routing tables. For example, if a Diameter message is sent from node1.yourcompany.com to node2.yourcompany.com, the message is routed within the same realm (yourcompany.com) without needing to be forwarded externally.

Inter-Realm Routing
When the Destination-Realm differs from the Origin-Realm (e.g. from node1.yourcompany.com to node1.othercompany.com), the message needs to be routed through an intermediate node or Diameter agent (such as a Diameter Proxy) that can forward the message to the appropriate realm. 

Architecture

Fig.1 - Architecture of network connection between Local Cluster and remote Destination in Mobius Diameter Gateway

At the core of the architecture is the Local Cluster, which represents the local Diameter cluster, defined by its Default Local Host and Default Local Realm. The Default Local Host is the IP address or hostname of the machine where the Mobius Diameter instance is running, allowing it to be addressed by other nodes within the network. The Default Local Realm acts as a domain or network segment identifier that facilitates logical grouping and routing of Diameter messages.

On the other end is the Destination, representing the remote network that the local Diameter node communicates with. The Destination Host is the hostname of this remote node, while the Destination Realm serves as its administrative or network domain identifier, supporting the routing of messages within the remote network.

Between the local and destination nodes, a Server is configured for each destination, defining how a particular Diameter application will communicate with the remote peer. The server handles the configuration for application-specific exchanges, ensuring that messages are properly formatted and routed based on the desired use case.

The communication between the local server and the destination host is established through Links. These transport links use either SCTP or TCP protocols to provide a transport layer over which Diameter messages are exchanged between the servers at both ends. Links ensure that the local Diameter instance can send requests and receive responses from the destination node reliably.

Diameter Settings Configuration

To configure Diameter Settings in Mobius Diameter Gateway:

• Navigate to the Diameter Settings page in the UI.
• Enter the following general configuration parameters:

• After filling in the required fields, click Save to store the configuration.

Destination Setup

A Destination in the Mobius Diameter Gateway represents the target network element or service that the Diameter instance will communicate with. This could be another Diameter node, server, or service to which the Diameter client sends requests or from which it receives responses.
The primary purpose of a Destination is to define the remote network cluster with which the Mobius Diameter node will establish a communication channel.
It allows the configuration of specific parameters for connecting to the remote Diameter node, such as the Destination Name, Destination Realm, and the IP/host configuration.

Workflow:

• Configuration: During the setup, the user specifies the Destination Name, Destination Realm, and the local Diameter host/realm information.
• Connection: Once the configuration is complete and saved, the Mobius Diameter node uses this information to establish a connection with the remote peer.
• Routing: All Diameter requests sent by the local node to this remote peer will be routed based on this Destination configuration. For example, requests targeting a specific service (e.g., Credit Control) will be routed to the appropriate Destination realm and host.

By having multiple Destinations, the Diameter node can communicate with different peers or services within the network.

Once the Diameter parameters are configured, set up destinations by following these steps:

• Navigate to the Destinations tab and click Add new row.
• Enter the following configuration parameters:

• Once all fields are completed, click Save to store the destination settings.

Server Setup

A Server in the Mobius Diameter Gateway setup represents the specific configuration tied to a Destination that is responsible for handling communication with a peer for a particular application. Each server defines how a Diameter application will operate for the defined Destination.
The Server defines the particular application that will be supported and used for communication with the defined Destination.
It links the Destination to a specific Diameter application, specifying the host (peer) and enabling message exchanges relevant to that application.
Workflow:

• Association: The Server is associated with a particular Destination, and it specifies the Diameter application that will be used in communication with that Destination.
• Application Support: For instance, if the server is configured for Credit Control (GY), all messages related to credit control functions will flow through this Server.
• Message Handling: The Server is responsible for sending and receiving messages for the Diameter application, ensuring that the appropriate Diameter requests and responses are exchanged between the local and remote nodes.

Multiple Servers can be created under the same Destination to support different Diameter applications, allowing versatile and scalable communication.
The next step is to set up the server associated with the destination:

• Navigate to the Servers tab under the respective destination.
• Click Add new row.
• In the Server Setup dialog:

• Click Save to store the server configuration.

Links Setup

A Link in the Mobius Diameter Gateway represents the transport connection between the Local Cluster and a Destination. It defines the communication channel (either SCTP or TCP) through which Diameter messages will be exchanged between the local node and the remote peer.
The Link defines whether the local node will act as a Client (initiating requests) or a Server (responding to requests) for the specific connection.
The Link specifies the IP addresses and ports for both the local and remote peers, creating the path for message transmission.
In practical setups, multiple Links can be created, one for each Server and Client communication. Each Link defines a unique communication path for message routing based on the configured ports and roles.
To set up the links between server and destination:

• Navigate to the Links tab under the server you created.
• Click Add new row.
• In the Link Setup dialog:

• Click Save to store the link configuration.

Testing the Setup

Once all configurations are completed, verify that the setup is functional:

• The destination should be visible in the Destinations tab.
• The server should be listed under the configured destination, and its status should show as Enabled.
• Ensure that the links are operational, and the status shows as Up.

This concludes the setup and configuration process for the Mobius Diameter Gateway UI. Be sure to test connectivity and message exchange to ensure all parameters are functioning as expected.