Can Diameter Signaling Controller capabilities overcome architectural issues within the LTE/EPC/Diameter network, thus allowing service providers the ability to build a topology that best meets their needs? In our previous posts we have discussed different types of EPC network architectures from mesh to centralized to core/edge. I think, based on all the discussion throughout the industry, we have come to the conclusion that mesh networks are not acceptable. So, the question remains, are there advantages and disadvantages to both the centralized and core/edge approaches, and furthermore, can capabilities in Diameter overcome the disadvantages?
Centralized Diameter Routing Challenges
The LTE/EPC/Diameter central routing topology is characterized by all nodes within a carrier’s network being connected to the central diameter router. Additionally, all external network connections would also terminate at the central Diameter router. This combination of a complex LTE/EPC network, numerous interconnected networks, and vendors’ wide diversity of equipment, presents service providers with the challenge of setting up routing rules, shaping traffic, and handling Diameter protocol inconsistencies on an interconnected network basis. This massive routing configuration leads to complexity and increases the chance of errors when making routing/traffic rules changes.
Centralized Diameter Routing Topology
Centralized Diameter Routing Solutions
An efficient approach to the dilemma of massive routing databases and traffic shaping to individual areas of the network is for Diameter Routing Agents to include routing segmentation concepts. This routing segmentation would be used to virtulize instances of the Diameter Routing Agent on a single platform and would include individual routing and traffic shaping tables on a per Diameter Routing Agent instance. This concept would be used to subdivide the network into regions, territories, or any other category that meets the business and architectural requirements of the service provider. Furthermore, routing segmentation has the following benefits:
- Routing table on a per region basis
- Traffic shaping on a per region basis
- Protocol inconsistencies on a per region or per network element basis
- Reduction of administration errors (changes are made on a per instance basis)
- Maintains capital expenditures savings of centralized routing
Centralized LTE/EPC/Diameter Network with Routing Segmentation
Core/Edge Diameter Routing Challenges
In a LTE/EPC/Diameter Core/Edge network topology the issues of the core Diameter Routing Agent are similar to those in the centralized Diameter routing architecture, albeit reduced somewhat due to the more distributed nature of the network. Typically, the edge portion of the core/edge topology is the GSM Association (GSMA) recommended Diameter Edge Agent (DEA). This Diameter Edge Agent would be used to interface all interconnected networks. The questions to be answered regarding the Centralized DEA are:
- Can changes be made on an individual interconnected network basis?
- Do changes made on interconnected networks have to be made in the master routing database?
Core/Edge Diameter Routing Solutions
The use of Diameter routing segmentation within Diameter Edge Agents makes it possible to virtualize the DEAs on an interconnected basis while maintaining a single platform. Diameter routing segmentation will provide the capability to solve the following in the most efficient manner:
- Changing routing rules on a per interconnected network
- Traffic shaping per interconnected network
- Topology hiding per interconnected network
- Protocol inconsistencies per interconnected network
- Firewalling of incoming Diameter messages per interconnected network.
Diameter Routing Agents including routing segmentation capabilities give LTE/EPC/Diameter service providers the ability to design, implement, and maintain the most efficient and cost effective architectures to meet their individual business requirements.