S6a/S6d Topology Hiding is applied only to the S6a/S6d Command Codes defined in 3GPP TS 29.272, Mobility Management Entity (MME) and Serving GPRS Support Node (SGSN) related interfaces based on Diameter protocol, and requires knowing which S6a/S6d messages are HSS-initiated versus MME/SGSN-initiated.
S6a/S6d HSS Topology Hiding is concerned with hiding the identity(s) of a Protected Network's HSS when it exchanges messages with Untrusted Networks. An HSS's Hostname is embedded in the Origin-Host and Session-Id AVPs sent in Request messages and in the Origin-Host AVP sent in Answer messages.
S6a/S6d HSS Topology Hiding determines which entity (HSS or MME/SGSN) initiated a message based on the Command Code in the message.
S6a/S6d HSS Topology Hiding can be enabled for each Protected Network by assigning an S6a/S6d HSS Topology Hiding Configuration Set to the configured Protected Network.
MME/SGSN Topology Hiding is concerned with hiding the identity of a Protected Home Network's MME/SGSNs, as well as the number of MME/SGSNs in the network, when it exchanges messages with Untrusted Networks. A MME/SGSN's identity is embedded in the Origin-Host and Session-Id AVPs sent in Request messages and in the Origin-Host AVP sent in Answer messages.
MME/SGSN Topology Hiding determines which entity (HSS or MME/SGSN) initiated an S6a/S6d message, based on the Command Code in the message.
MME/SGSN Topology Hiding can be enabled for each Protected Network by assigning an MME/SGSN Topology Hiding Configuration Set to the configured Protected Network.
Note:
S9 PCRF topology hiding is only applied to the S9 and Rx command codes.S9 AF/pCSCF Topology Hiding is only applied to the Rx command codes when Visited Access Roaming Architecture is used and AF/pCSCF is communicating to H-PCRF in Proxy Mode. It allows the operator to hide the host names of AF/pCSCF's in a Protected Network as well as the number of AF/pCSCF's from Untrusted Networks.
Path Topology Hiding is Diameter application-independent, and can be applied to any Diameter Command Code.
Path Topology Hiding can be enabled for each Protected Network by assigning a Path Topology Hiding Configuration Set to the configured Protected Network.