Diameter Protocol

  1. New :: RFC-6737 (DIAMETER Capabilities Update)
  2. New :: Capture Diameter Messages without wire-shark.
  3. New :: RFC-6733 (Diameter Base Protocol)
  1. DIAMETER at a Glance  [Frequently Asked Diameter Questions]
  1. Introduction to Diameter
  2. Improvements of Diameter over RADIUS
  3. Diameter Message Structure and Message Flow
  4. Diameter AVP Structure
  5. Diameter Peer Discovery
  6. Capability Negotiation
  7. DIAMETER Connection Establishment
  8. Election Process
  9. Diameter Agents
  10. Diameter Peer Connection and Disconnection
  11. Peer Table Explained
  12. Realm Based Routing Table
  13. Diameter Message Processing
  14. Message Processing at Redirect Agent
  15. Securing Diameter Messages
  16. IPsec
  17. TLS Transport Layer Security
  18. Transport Failure Detection
  19. Diameter Address Format
  20. Diameter Errors
  21. Result Code and Experimental Result Code.
  22. List of Result Codes
  23. List of Experimental Result codes
  24. Diameter Sessions and Session States
  25. Authorization Session
  26. Diameter Session establishment and disconnection
  27. Important Session AVPs and their usage in session.


  1. Can i get some information about Diameter Hd interface between HSS and HLR?
    What are the diameter messages exchanged between the two nodes during 4G to 3G fallback and vice versa?

  2. This comment has been removed by the author.

  3. Que implementación hoy en día seria útil o beneficioso este Protocolo ??

  4. Is it legal to send a Diameter request to one host (dest-host AVP = x) and receive a diameter answer from a different host (orig-host AVP=Y)?

    1. Diameter answer doesn't use destination host/realm to reach the destination. it just back trace the path by which request was received. So you can't send Diameter answer from different host.

    2. Thanks for the answer but Im not sure I understand.
      Can you alobrate regaring the trace back?
      Because the problem I thought about is that a peer receives an answer from a different peer then expected. You write that there will be problem with routing the answer and I dont understand why.

    3. Hi Ben,
      In your scenario you must be using realm based routing on DRA, so DRA is not considering the Destination host AVP in request message.
      You must be sending the request to some host X through DRA, but getting response from host Y.
      The actual thing is that host Y have received the request instead of host X because of the routing policy at DRA.

      Note: Diameter Answer will always come from only the host which has received the request.

  5. Hi,
    According 3GPP TS 32.299 do you know if there is any avp to carry the imsi of the called party address if it is available? For exemple for SIP URI forrmat numbers do you know if MTAS support the imsi parameter inside the called-party-address avp?

  6. website link stop working, only Front page is working

    1. Hi Mayoor

      Thanks for your feedback.
      Please check now.

      Happy to server you better again
      Team Diameter