SS7 – Diameter Interconnect
Diameter for Mobility Management Interworking LTE & Legacy Interworking Use Case
Connectivity to legacy elements, protocols, and interfaces is one major aspect of 4G technology that was designed to avoid full replacement of network nodes. However, the mix of LTE and legacy elements, protocols and interfaces require the right kind of connectivity to guarantee a smooth transition and to deliver the promised cost reductions.
The Signaling Delivery Controller (SDC) supports an interworking function (IWF) that interconnects between legacy SS7 elements within a mobile network or roaming scenarios that involve legacy network elements. This signaling translation function supports widest range of message oriented protocols like SS7, and also SIP, RADIUS, HTTP/SOAP, LDAP, GTP’, JMS and others, ranging from simple message translation and adaptation to complex multi-protocol translation of state machines (e.g, Diameter Session<->TCAP Dialogues).
Standard Bodies 3GPP and GSMA Defined
Industry standard bodies 3GPP and GSMA have defined the Interworking Function (IWF) that specifies Diameter to SS7/MAP and vice versa for interworking. By supporting SS7 legacy protocol with the IWF, Traffix enables operators to enable 2G/3G network elements to communicate with LTE elements such as Mobility Management Entity (MME) and Home Subscriber Server (HSS) for subscriber management. Other use cases enabled by the SDC IWF include reciprocal roaming of new (greenfield) LTE operators on non-LTE networks, and allowing connectivity of an SS7 Equipment Identity Register (EIR) in an LTE network.
The Inter-working Function (IWF) of Diameter/SS7-MAP solution enables seamless connection of LTE elements, interfaces and protocols to legacy SS7, thereby delivering cost savings on the reuse of legacy elements.
The SDC is designed to support the following capabilities:
- IWF Mobility Management – MAP/Diameter interworking for S6a, S6d and S13 interfaces based on TS 29.305
TS 29.305 specifies the Inter Working Function (IWF) between MAP-based Gr, Gf interfaces and Diameter-based S6a, S6d, S13, S13a interfaces
- Roaming – MAP/Diameter roaming interworking for S6a and S6d based on IR.88
The GSMA IR.88 provides a standardized view on how LTE networks can interwork when users roam onto a network different from their home network.