View Source Standards Compliance

The table below summarizes the diameter application's compliance with RFC 6733. Since the diameter application isn't a Diameter node on its own, compliance is strictly the responsibility of the user in many cases, diameter providing the means for the user to be compliant rather than being compliant on its own.

The Compliance column notes C (Compliant) if the required functionality is implemented, PC (Partially Compliant) if there are limitations, NC (Not Compliant) if functionality is not implemented, or a dash if text is informational or only places requirements that must be met by the user's implementation.

Capitalized Diameter refers to the protocol, lowercase diameter to the Erlang application.

RFC 6733 - Diameter Base Protocol

SectionTitleComplianceNotes
1Introduction—
1.1Diameter Protocol—
1.1.1Description of the Document Set—
1.1.2Conventions Used in This Document—
1.1.3Changes from RFC 3588—It is possible to configure a 3588 dictionary in order to get 3588 semantics, where the differ from 6733.
1.2Terminology—
1.3Approach to Extensibility—The dictionary interface documented in diameter_dict(4) provides extensibility, allowing the user to defined new AVPs, commands, and applications. Ready dictionaries are provided for the RFC 6733 common message, base accounting, and relay applications, as well as for RFC 7683, Diameter Overload Indicator Conveyance.
1.3.1Defining New AVP Values—
1.3.2Creating New AVPs—New AVPs can be defined using the dictionary interface. Both RFC data formats and extensions are supported.
1.3.3Creating New Commands—New commands can be defined using the dictionary interface.
1.3.4Creating New Diameter Applications—New applications can be defined using the dictionary interface.
2Protocol Overview—Session state is the responsibility of the user.   The role of a Diameter node is determined by the user's implementation.
2.1TransportPCPorts are configured by the user: diameter places no restrictions.   The transport interface documented in diameter_transport allows the user to implement their own methods. Ready support is provided for TCP, TCP/TLS, and SCTP, but not DTLS/SCTP.   Multiple connections to the same peer is possible. ICMP messages are not interpreted.
2.1.1SCTP GuidelinesCUnordered sending is configurable in diameter_sctp. There is no special handling of DPR/DPA: since a user that cares about pending answers should wait for them before initiating DPR.   A PPID can be configured with a a gen_sctp sctp_default_send_param option.
2.2Securing Diameter MessagesPCDTLS is not supported by diameter_sctp. See also 2.1.
2.3Diameter Application Compliance—
2.4Application IdentifiersCThe user configures diameter with the identifiers to send at capabilities exchange, along with corresponding dictionaries defining the messages of the applications.
2.5Connections vs. SessionsCConnections are realized by configuring transport. Sessions are the responsibility of the user.
2.6Peer TablePCRouting is implemented by the user in callbacks documented in diameter_app. A peer table of the documented form is not exposed to the user.
2.7Routing TablePCSee 2.6. A routing table of the documented form is not exposed to the user.
2.8Role of Diameter AgentsCMost role-specific behaviour is implemented by the user. How a node advertises itself at capabilities exchange is determined by user configuration.
2.8.1Relay AgentsC
2.8.2Proxy AgentsC
2.8.3Redirect AgentsC
2.8.4Translation AgentsC
2.9Diameter Path Authorization—Authorization is the responsibility of the user.
3Diameter HeaderCHop-by-Hop and End-to-End Identifiers are set by diameter when sending outgoing requests.
3.1Command CodesC
3.2Command Code Format SpecificationCCommands are defined as CCF specifications in dictionary files.
3.3Diameter Command Naming Conventions—
4Diameter AVPsCAny required padding is added by diameter when encoding outgoing messages.
4.1AVP HeaderC
4.1.1Optional Header ElementsC
4.2Basic AVP Data FormatsC
4.3Derived AVP Data FormatsCArbitrary derived data formats are supported by the dictionary interface.
4.3.1Common Derived AVP Data FormatsCBeware that RFC 6733 changed the DiameterURI transport/port defaults specified in RFC3588. Relying on the defaults can result in interoperability problems.
4.4Grouped AVP ValuesCThe M-bit on a component AVP of a Grouped AVP that does not set M is ignored: such AVPs are not regarded as erroneous at decode.   Grouped AVPs are defined as CCF specifications in dictionary files.
4.4.1Example AVP with a Grouped Data Type—
4.5Diameter Base Protocol AVPsCThe base AVPs are defined in the common dictionary provided by diameter. There are common dictionaries for both RFC 3588 and RFC 6733 since the latter made changes to both syntax and semantics.
5Diameter Peers—
5.1Peer ConnectionsPCA peer's DiameterIdentity is not required when initiating a connection: the identify is received at capabilities exchange, at which time the connection can be rejected if the identity is objectionable.   The number of connections established depends on the user's configuration. Multiple connections per peer is possible.
5.2Diameter Peer DiscoveryNCNo form of peer discovery is implemented. The user can implement this independently of diameter if required.
5.3Capabilities ExchangeCAll supported applications are sent in CEA. The user can reject an incoming CER or CEA in a configured callback.   Both transport security at connection establishment and negotiated via an Inband-Security AVP are supported.
5.3.1Capabilities-Exchange-RequestCCER is sent and received by diameter.
5.3.2Capabilities-Exchange-AnswerCCEA is sent and received by diameter.
5.3.3Vendor-Id AVPC
5.3.4Firmware-Revision AVPC
5.3.5Host-IP-Address AVPC
5.3.6Supported-Vendor-Id AVPC
5.3.7Product-Name AVPC
5.4Disconnecting Peer ConnectionsCDPA will not be answered with error: a peer that wants to a avoid a race can wait for pending answers before sending DPR.
5.4.1Disconnect-Peer-RequestCDPR is sent by diameter in response to configuration changes requiring a connection to be broken. The user can also send DPR.
5.4.2Disconnect-Peer-AnswerCDPR is answered by diameter.
5.4.3Disconnect-Cause AVPC
5.5Transport Failure Detection—
5.5.1Device-Watchdog-RequestCDWR is sent and received by diameter. Callbacks notify the user of transitions into and out of the OKAY state.
5.5.2Device-Watchdog-AnswerCDWA is sent and received by diameter.
5.5.3Transport Failure AlgorithmC
5.5.4Failover and Failback ProceduresC
5.6Peer State MachinePCThe election process is modified as described in 5.6.4.
5.6.1Incoming ConnectionsC
5.6.2Events—
5.6.3Actions—
5.6.4The Election ProcessPCAs documented, the election assumes knowledge of a peer's DiameterIdentity when initiating a connection, which diameter doesn't require. Connections will be accepted if configuration allows multiple connections per peer to be established or there is no existing connection. Note that the election process is only applicable when multiple connections per peer is disallowed.
6Diameter Message Processing—
6.1Diameter Request Routing Overview—Routing is performed by the user. A callback from diameter provides a list of available suitable peer connections.
6.1.1Originating a RequestCRequests are constructed by the user; diameter sets header fields as defined in the relevant dictionary.
6.1.2Sending a RequestC
6.1.3Receiving RequestsCLoops are detected by diameter when the return value of a request callback asks that a request be forwarded. Loop detection in other cases is the responsibility of the user.
6.1.4Processing Local RequestsCThe user decides whether or not to process a request locally in the request callback from diameter.
6.1.5Request ForwardingPCSee 2.6.
6.1.6Request RoutingPCSee 2.7.
6.1.7Predictive Loop AvoidanceCSee 6.1.3.
6.1.8Redirecting RequestsPCSee 2.6.
6.1.9Relaying and Proxying RequestsCA Route-Record AVP is appended by diameter when the return value of a request callback asks that a request be forwarded. Appending the AVP in other cases is the responsibility of the user.
6.2Diameter Answer ProcessingCAnswer message are constructed by the user, except in the case of some protocol errors, in which case the procedures are followed.
6.2.1Processing Received AnswersCAnswers with an unknown Hop-by-Hop Identifier are discarded.
6.2.2Relaying and Proxying Answers—Modifying answers is the responsibility of the user in callbacks from diameter.
6.3Origin-Host AVPCThe order of AVPs in an encoded message is determined by the CCF of the message in question.   AVPs defined in the RFC are defined in dictionaries provided by diameter. Their proper use in application messages is the responsibility of the user.
6.4Origin-Realm AVPC
6.5Destination-Host AVPC
6.6Destination-Realm AVPC
6.7Routing AVPs—
6.7.1Route-Record AVPC
6.7.2Proxy-Info AVPC
6.7.3Proxy-Host AVPC
6.7.4Proxy-State AVPC
6.8Auth-Application-Id AVPC
6.9Acct-Application-Id AVPC
6.10Inband-Security-Id AVPCSee 2.1.
6.11Vendor-Specific-Application-Id AVPCNote that the CCF of this AVP is not the same as in RFC 3588.
6.12Redirect-Host AVPC
6.13Redirect-Host-Usage AVPC
6.14Redirect-Max-Cache-Time AVPC
7Error HandlingCAnswers are formulated by the user in most cases. Answers setting the E-bit can be sent by diameter itself in response to a request that cannot be handled by the user.
7.1Result-Code AVPC
7.1.1InformationalC
7.1.2SuccessC
7.1.3Protocol ErrorsCResult codes 3001, 3002, 3005, and 3007 can be sent in answers formulated by diameter, if configured to do so.
7.1.4Transient FailuresCResult code 4003 is sent in CEA if there is an existing connection to the peer in question and configuration does not allow more than one.
7.1.5Permanent FailuresCMessage reception detects 5001, 5004, 5005, 5008, 5009, 5010, 5011, 5014, 5015, and 5017 errors. It ignores 5013 errors at the admonition of sections 3 and 4.1.   Note that RFC 3588 did not allow 5xxx result codes in answers setting the E-bit, while RFC 6733 does. This is a potential interoperability problem since the Diameter protocol version has not changed.
7.2Error BitC
7.3Error-Message AVPCThe user can include this AVP as required.
7.4Error-Reporting-Host AVPCThe user can include this AVP as required.
7.5Failed-AVP AVPCThe user constructs application-specific messages, but diameter provides failed AVPs in message callbacks. Failed component AVPs are grouped within the relevant Grouped AVPs.
7.6Experimental-Result AVPC
7.7Experimental-Result-Code AVPC
8Diameter User Sessions—Authorization and accounting AVPs are defined in provided dictionaries. Their proper use is the responsibility of the user.
8.1Authorization Session State Machine—Authorization is the responsibility of the user: diameter does not implement this state machine.
8.2Accounting Session State Machine—Accounting is the responsibility of the user: diameter does not implement this state machine.
8.3Server-Initiated Re-Auth—
8.3.1Re-Auth-RequestC
8.3.2Re-Auth-AnswerC
8.4Session Termination—Session-related messages and AVPs are defined in provided dictionaries. Their proper use is the user's responsibility.
8.4.1Session-Termination-RequestC
8.4.2Session-Termination-AnswerC
8.5Aborting a Session—Session-related messages and AVPs are defined in provided dictionaries. Their proper use is the user's responsibility.
8.5.1Abort-Session-RequestC
8.5.2Abort-Session-AnswerC
8.6Inferring Session Termination from Origin-State-Id—Session-related messages and AVPs are defined in provided dictionaries. Their proper use is the user's responsibility.
8.7Auth-Request-Type AVPC
8.8Session-Id AVPC
8.9Authorization-Lifetime AVPC
8.10Auth-Grace-Period AVPC
8.11Auth-Session-State AVPC
8.12Re-Auth-Request-Type AVPC
8.13Session-Timeout AVPC
8.14User-Name AVPC
8.15Termination-Cause AVPC
8.16Origin-State-Id AVPC
8.17Session-Binding AVPC
8.18Session-Server-Failover AVPC
8.19Multi-Round-Time-Out AVPC
8.20Class AVPC
8.21Event-Timestamp AVPC
9Accounting—Accounting-related messages and AVPs are defined in provided dictionaries. Their proper use is the user's responsibility.
9.1Server Directed Model—
9.2Protocol Messages—
9.3Accounting Application Extension and Requirements—
9.4Fault Resilience—
9.5Accounting Records—
9.6Correlation of Accounting Records—
9.7Accounting Command Codes—
9.7.1Accounting-RequestC
9.7.2Accounting-AnswerC
9.8Accounting AVPs—
9.8.1Accounting-Record-Type AVPC
9.8.2Acct-Interim-Interval AVPC
9.8.3Accounting-Record-Number AVPC
9.8.4Acct-Session-Id AVPC
9.8.5Acct-Multi-Session-Id AVPC
9.8.6Accounting-Sub-Session-Id AVPC
9.8.7Accounting-Realtime-Required AVPC
10AVP Occurrence Tables—
10.1Base Protocol Command AVP Table—
10.2Accounting AVP Table—
11IANA Considerations—
11.1AVP Header—
11.1.1AVP Codes—
11.1.2AVP Flags—
11.2Diameter Header—
11.2.1Command Codes—
11.2.2Command Flags
11.3AVP Values—
11.3.1Experimental-Result-Code AVP—
11.3.2Result-Code AVP Values—
11.3.3Accounting-Record-Type AVP Values—
11.3.4Termination-Cause AVP Values—
11.3.5Redirect-Host-Usage AVP Values—
11.3.6Session-Server-Failover AVP Values—
11.3.7Session-Binding AVP Values—
11.3.8Disconnect-Cause AVP Values—
11.3.9Auth-Request-Type AVP Values—
11.3.10Auth-Session-State AVP Values—
11.3.11Re-Auth-Request-Type AVP Values—
11.3.12Accounting-Realtime-Required AVP Values—
11.3.13Inband-Security-Id AVP (code 299)—
11.4_diameters Service Name and Port Number Registration—
11.5SCTP Payload Protocol Identifiers—
11.6S-NAPTR Parameters—
12Diameter Protocol-Related Configurable Parameters—
13Security ConsiderationsPCSee 2.1.   IPsec is transparent to diameter.
13.1TLS/TCP and DTLS/SCTP UsagePCSee 2.1.
13.2Peer-to-Peer Considerations—
13.3AVP Considerations—
14References—
14.1Normative References—
14.2Informative References—

Table: RFC 6733 Compliance