Editing Diameter (protocol) (section)

=== Commands ===
Each command Request/Answer pair is assigned a command code. Whether it is the request or answer is identified via the 'R' bit in the Command Flags field of the header.

The values 0-255 are reserved for RADIUS backward compatibility.
The values 256-16777213 are for permanent, standard commands allocated by [[Internet Assigned Numbers Authority|IANA]].
The values 16777214 and 16777215 (hex 0xFFFFFE and 0xFFFFFF) are reserved for experimental and testing purposes.

A Command Code is used to determine the action that is to be taken for a particular message. Some common Diameter commands defined in the protocol (base and applications) are:

{| class="wikitable sortable"
|-
!align=left|Command-Name!!Abbr.!!Code!!Application
|-
| AA-Request||AAR||265||Diameter NAS Application - RFC 7155
|-
| AA-Answer||AAA||265||Diameter NAS Application - RFC 7155
|-
| Diameter-EAP-Request||DER||268||Diameter EAP Application - RFC 4072
|-
| Diameter-EAP-Answer||DEA||268||Diameter EAP Application - RFC 4072
|-
| Abort-Session-Request||ASR||274||Diameter base
|-
| Abort-Session-Answer||ASA||274||Diameter base
|-
| Accounting-Request||ACR||271||Diameter base
|-
| Accounting-Answer||ACA||271||Diameter base
|-
| [[Diameter Credit-Control Application#Message structures|Credit-Control-Request]]||CCR||272||Diameter Credit-Control Application - RFC 8506 (Obsoletes RFC 4006)
|-
| [[Diameter Credit-Control Application#Message structures|Credit-Control-Answer]]||CCA||272||Diameter Credit-Control Application - RFC 8506 (Obsoletes RFC 4006)
|-
| Capabilities-Exchange-Request||CER||257||Diameter base
|-
| Capabilities-Exchange-Answer||CEA||257||Diameter base
|-
| Device-Watchdog-Request||DWR||280||Diameter base
|-
| Device-Watchdog-Answer||DWA||280||Diameter base
|-
| Disconnect-Peer-Request||DPR||282||Diameter base
|-
| Disconnect-Peer-Answer||DPA||282||Diameter base
|-
| Re-Auth-Request||RAR||258||Diameter base
|-
| Re-Auth-Answer||RAA||258||Diameter base
|-
| Session-Termination-Request||STR||275||Diameter base
|-
| Session-Termination-Answer||STA||275||Diameter base
|-
| User-Authorization-Request||UAR||283||Diameter SIP Application - RFC 4740
|-
| User-Authorization-Answer||UAA||283||Diameter SIP Application - RFC 4740
|-
| Server-Assignment-Request||SAR||284||Diameter SIP Application - RFC 4740
|-
| Server-Assignment-Answer||SAA||284||Diameter SIP Application - RFC 4740
|-
| Location-Info-Request||LIR||285||Diameter SIP Application - RFC 4740
|-
| Location-Info-Answer||LIA||285||Diameter SIP Application - RFC 4740
|-
| Multimedia-Auth-Request||MAR||286||Diameter SIP Application - RFC 4740
|-
| Multimedia-Auth-Answer||MAA||286||Diameter SIP Application - RFC 4740
|-
| Registration-Termination-Request||RTR||287||Diameter SIP Application - RFC 4740
|-
| Registration-Termination-Answer||RTA||287||Diameter SIP Application - RFC 4740
|-
| Push-Profile-Request||PPR||288||Diameter SIP Application - RFC 4740
|-
| Push-Profile-Answer||PPA||288||Diameter SIP Application - RFC 4740
|-
| User-Authorization-Request||UAR||300||Diameter base (3GPP) RFC 3589
|-
| User-Authorization-Answer||UAA||300||Diameter base (3GPP) RFC 3589
|-
| Server-Assignment-Request||SAR||301||Diameter base (3GPP) RFC 3589
|-
| Server-Assignment-Answer||SAA||301||Diameter base (3GPP) RFC 3589
|-
| Location-Info-Request||LIR||302||Diameter base (3GPP) RFC 3589
|-
| Location-Info-Answer||LIA||302||Diameter base (3GPP) RFC 3589
|-
| Multimedia-Auth-Request||MAR||303||Diameter base (3GPP) RFC 3589
|-
| Multimedia-Auth-Answer||MAA||303||Diameter base (3GPP) RFC 3589
|-
| Registration-Termination-Request||RTR||304||Diameter base (3GPP) RFC 3589
|-
| Registration-Termination-Answer||RTA||304||Diameter base (3GPP) RFC 3589
|-
| Push-Profile-Request||PPR||305||Diameter base (3GPP) RFC 3589
|-
| Push-Profile-Answer||PPA||305||Diameter base (3GPP) RFC 3589
|-
| User-Data-Request||UDR||306||Diameter base (3GPP) RFC 3589
|-
| User-Data-Answer||UDA||306||Diameter base (3GPP) RFC 3589
|-
| Profile-Update-Request||PUR||307||Diameter base (3GPP) RFC 3589
|-
| Profile-Update-Answer||PUA||307||Diameter base (3GPP) RFC 3589
|-
| Subscribe-Notifications-Request||SNR||308||Diameter base (3GPP) RFC 3589
|-
| Subscribe-Notifications-Answer||SNA||308||Diameter base (3GPP) RFC 3589
|-
| Push-Notification-Request||PNR||309||Diameter base (3GPP) RFC 3589
|-
| Push-Notification-Answer||PNA||309||Diameter base (3GPP) RFC 3589
|-
| Bootstrapping-Info-Request||BIR||310||Diameter base (3GPP) RFC 3589
|-
| Bootstrapping-Info-Answer||BIA||310||Diameter base (3GPP) RFC 3589
|-
| Message-Process-Request||MPR||311||Diameter base (3GPP) RFC 3589
|-
| Message-Process-Answer||MPA||311||Diameter base (3GPP) RFC 3589
|-
| Update-Location-Request||ULR||316|| 3GPP TS 29.272 [RFC 5516]
|-
| Update-Location-Answer||ULA||316|| 3GPP TS 29.272 [RFC 5516]
|-
| Cancel-Location-Request||CLR||317|| 3GPP TS 29.272 [RFC 5516]
|-
| Cancel-Location-Answer||CLA||317|| 3GPP TS 29.272 [RFC 5516]
|-
| Authentication-Information-Request||AIR||318|| 3GPP TS 29.272 [RFC 5516]
|-
| Authentication-Information-Answer||AIA||318|| 3GPP TS 29.272 [RFC 5516]
|-
| Insert-Subscriber-Data-Request||IDR||319|| 3GPP TS 29.272 [RFC 5516]
|-
| Insert-Subscriber-Data-Answer||IDA||319|| 3GPP TS 29.272 [RFC 5516]
|-
| Delete-Subscriber-Data-Request||DSR||320|| 3GPP TS 29.272 [RFC 5516]
|-
| Delete-Subscriber-Data-Answer||DSA||320|| 3GPP TS 29.272 [RFC 5516]
|-
| Purge-UE-Request||PER||321|| 3GPP TS 29.272 [RFC 5516]
|-
| Purge-UE-Answer||PEA||321|| 3GPP TS 29.272 [RFC 5516]
|-
| Notify-Request||NR||323|| 3GPP TS 29.272 [RFC 5516]
|-
| Notify-Answer||NA||323|| 3GPP TS 29.272 [RFC 5516]
|-
| Provide-Location-Request||PLR||8388620||3GPP-LCS-SLg (Application-ID 16777255)
|-
| Provide-Location-Answer||PLA||8388620||3GPP-LCS-SLg (Application-ID 16777255)
|-
| Routing-Info-Request||RIR||8388622||3GPP-LCS-SLh (Application-ID 16777291)
|-
| Routing-Info-Answer||RIA||8388622||3GPP-LCS-SLh (Application-ID 16777291)
|-
| AA-Mobile-Node-Request||AMR||260|| Diameter Mobile IPv4 - RFC 4004
|-
| AA-Mobile-Node-Answer||AMA||260|| Diameter Mobile IPv4 - RFC 4004
|-
| Home-Agent-MIP-Request||HAR||262|| Diameter Mobile IPv4 - RFC 4004
|-
| Home-Agent-MIP-Answer||HAA||262|| Diameter Mobile IPv4 - RFC 4004
|-
| Configuration-Information-Request||CIR||8388718|| S6t per 3GPP TS 29.336
|-
| Configuration-Information-Answer||CIA||8388718|| S6t per 3GPP TS 29.336
|-
| Reporting-Information-Request||RIR||8388719|| S6t per 3GPP TS 29.336
|-
| Reporting-Information-Answer||RIA||8388719|| S6t per 3GPP TS 29.336
|-
| NIDD-Information-Request||NIR||8388726|| S6t per 3GPP TS 29.336
|-
| NIDD-Information-Answer||NIA||8388726|| S6t per 3GPP TS 29.336
|}