Diameter Address Format


Every diameter address (Diameter Node Address) should follow the DiameterIdentity format. DiameterIdentity is used to uniquely identify a Diameter Node.DiameteIdentity has following format

DiameterIdentity=FQDN (DiameterURI)

DiameterURI MUST follow the URI syntax given below

aaa://FQDN [Port][Transport][Protocol]  //No Transport security
aaas://FQDN [Port][Transport][Protocol]  //Transport security used

= Fully Qualified Host Name
Port = :<1*digit>
Port Number of the port use for listen the incoming connection if Absent the default Diameter port 3868 is assumed.
Transport= ;transport=
Name of the transport used to listen. if Absent then default SCTP is assumed. we shall not mention the UDP when Protocol field is set to diameter.
Protocol = ;protocol=
If absent then by default diameter is assumed.

Example of Valid diameter host identities

1) aaa://host.example.com
on default port (3868), default transport(SCTP) and default protocol(diameter)

 Port=6666, Transport=tcp , Protocol=diameter


Your Comments/Suggestions and Questions are always welcome. We would try to clarify doubts with best of our knowledge. So feel free to put Questions.


  1. Thanks for this Blog.It is very useful.
    Could you please explain the peer state machine, especially what is this I (initiator connection ) and R (responder connection) means.Thanks in advance.

    1. Please visit following link

      Diameter Sessions and Session States

      This will might help you

      Thanks for your query.
      Happy to help you again.

  2. what is the difference between DiameterIdentity and DiameterURI ?

    1. Hi Naseem Rahman

      Difference is in the context where both are used.

      Diameter URI -- is used to uniquely identify a node as an abstract or physical resource

      Diameter Identity -- is used to identify a node in a realm, to protect loop detection during routing of a message to next peer.

      We hope above explanation shall help you.

      Thanks for your query.
      Happy to help you again.

  3. I am getting the Origin host as SOLKTXEAvCMM-L-NK-X-02.vzimstest.com which is basically a MME address in the ULR message.
    It does not contain the mccXXX.mncYYY.epc format in the Origin host.
    where can i find the specification of the Origin host and whether the origin host is SOLKTXEAvCMM-L-NK-X-02.vzimstest.com valid or not.

    1. Hi
      Format can be identified from 3gpp specification 29272 under "Visited-Network-Identifier" and "MIP-Home-Agent-Host".

  4. This comment has been removed by the author.

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