Diameter Relay Agent (DRA)

Optimizing Network with Diameter Relay Agent (DRA):

•A fully meshed Diameter network is regarded as quite complex in administration and configuration.

•To optimize the network architecture Diameter Relay Agents are introduced.

•Diameter Relay Agent is used to forward protocol messages to appropriate Diameter Server.

•DRA plays similar role as STP in SS7 networks.

 

 

 

Diameter Proxies:

 

In roaming case the visited MME has to contact the home HSS in order to fetch the profile of the subscriber.

S6a is pure IP interface with Diameter protocol at application layer

Diameter Based Protocol defines the function of Proxying:

•The operator will use edge proxies to connect to GRX provider

•Edge Proxy Agent is the only point of contact into and out of an operator network at Diameter application layer

•Multiple edge-proxies are recommended for resilience and scalability.

•A Diameter Proxy Agent has similar function as Diameter Relay Agent but it can modify the content of the message in order to address routing of diameter messages between different domains.

•Diameter Proxy Agent can modify messages to enable policy enforcement, resource usage control, admission and provisioning, functions that cannot be done by Diameter Relay Agent.

 

Roaming in LTE:

•Roaming for home routed traffic is the similar scenario used at the moment in 3G data networks

•Subscriber traffic is routed from Visited PLMN to Home PLMN via the GRX provider

•The S8 interface is the reference point between visited S-GW and home P-GW

•S8-GTP is a natural choice for roaming as many operators are using GTP for roaming in 2G/3G