Diameter Interfaces in LTE (EPC)

Evolved Packet Core majorly have 5 nodes.
1) Mobility Management Entity (MME)
2) Home Subscriber Server (HSS) 
3) Serving Gateway (S-GW)
4) PDN Gateway (P-GW)
5) Policy and Charging control entity/Function (PCRF)

These nodes interact then uses diameter based interfaces.



Dark Lines shows the major Diameter Interfaces in EPC.
Some times CSS data is not stored at HSS then S7a interface is used to communicated with MME. S7a is also diameter based interface

13 comments:

  1. Wow. Awesome article. Please do more articles like this in the future. Very informational and knowledgeable. I will expect more from you in the future. For now i will just bookmark your page and surely I'm gonna come back later to read more. Thank you to the writer!


    Rica
    www.imarksweb.org

    ReplyDelete
  2. Gx, Rx interface use diameter but you have not highlighted them, Why??

    ReplyDelete
    Replies
    1. Hi Nissar

      You are right.

      Thanks for your suggestion.
      Team-Diameter

      Delete
  3. I had one more doubt- EIR doesn't support diameter based s13/s13' directly right? It needs the Interworking functionality of a DRA to translate it to Gf interface?

    ReplyDelete
    Replies
    1. Dear Nissar Ali

      Following link shall help you.
      http://diameter-protocol.blogspot.in/2013/08/s13s13.html

      Thanks for your query.
      Happy to help you again.
      Team-Diameter

      Delete
  4. Hi All,

    Does anyone have any info on a free PCRF product I can use?

    ReplyDelete
  5. Hello all,
    Can some one help me to know the AVPs to consider for the VoLTE charging? Which all AVPs inside the Service-Information and PS-Information and IMS-Information AVPs of Ro interface?

    ReplyDelete
  6. Hello all,
    As there will be usage traffic from PGW as well as IMS side(either from SCSCF or AS), to charge for VoLTE which traffic to consider and can some one help me to know which all AVPs to consider for the charging and how to know which service have been used (like if call forwarding, call hold, call wait etc) happens while making the VoLTE call..how to know and how to charge it accordingly?

    ReplyDelete
  7. What is the difference between Diameter as a client and Diameter as a server?

    Till now I have installed and run freediameter. CER and CEA messages are exchanged between client and server successfully. But I am unable to grasp what makes one of the instance run every time as "client" and the other as "server" since both the client and server instance consists of the same source code. Is it dependent on the "diameter identity" or value of "ip" or by the action of a certain "flag" or "command line arguments"? I want my current client instance to run as a server and the current server instance to run as a client but I am unable to do so.

    ReplyDelete
    Replies
    1. There is no different specification for Client or Server.
      Node that initiate Request Message shall act as Client, Node that give Response to the received message shall act as a Server.

      A node can be acting as a server and client at the same time.
      In RCF 6733 you can also check the prefix I and prefix R for the same.

      Thanks for your query.

      Delete
  8. Thanks for making 3GPP TS description very easy. Please find list of all Diameter interfaces defined by 3GPP, IETF and ETSI for LTE based network architecture with link pointing to 3GPP Technical Specification document. https://www.packetforce.in/diameter-interfaces.htm

    ReplyDelete
  9. This comment has been removed by the author.

    ReplyDelete
  10. In diameter Gy interface is it optional to have sub AVP inside trigger AVP. Trigger AVP is part of MSCC AVP. If child AVP of trigger AVP (1264) are optional how we can make it as generic in our code to skip length check after decoding it's header.

    ReplyDelete