Topology Hiding Types

Topology Hiding can be a Diameter application-specific or Diameter application-independent procedure.

• Topology Hiding is Diameter application-specific if the rules apply only to a Diameter application-specific message set (such as S6a).
• Topology Hiding is Diameter application-independent if the rules apply to any Diameter message (any Command Code).

The information to be hidden can be controlled based upon the following Topology Hiding types:

• S6a/S6d Topology Hiding

  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 HidingHSS

    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

    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.

• S9 PCRF Topology Hiding
  S9 PCRF Topology Hiding is concerned with hiding the host names of PCRF's in a Protected Network, as well as the number of PCRFs from Untrusted Networks.

  Note:

  S9 PCRF topology hiding is only applied to the S9 and Rx command codes.
• S9 AF/pCSCF Topology Hiding

  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

  Path Topology Hiding is Diameter application-independent, and can be applied to any Diameter Command Code.

  Path Topology Hiding is concerned with hiding a Protected Network's Hostnames and the number of hosts in the following AVPs:

  • Route-Record AVP: Sent in Request messages. More than one Route-Record AVP can exist in a Request message.
  • Proxy-Host AVP: An AVP embedded in the grouped Proxy-Info AVP that is sent in Request and Answer messages. More than one Proxy-Host AVP can exist in a message.
  • Error-Reporting-Host AVP: Sent in Answer messages. More than one Error-Reporting-Host AVP can exist in an Answer message.

  Path Topology Hiding can be enabled for each Protected Network by assigning a Path Topology Hiding Configuration Set to the configured Protected Network.