| APEX, Application Exchange Core | 
|  | Description | Glossary | RFCs | Publications | Obsolete RFCs | 
| Protocol suite: | TCP/IP. | 
| Protocol type: | Application layer protocol. | 
| Ports: | 912 (TCP) relay - relay service. 913 (TCP) endpoint - relay service. | 
| SNMP MIBs: | |
| Working groups: | |
| Links: | 
APEX provides an extensible, asynchronous message relaying service for application layer programs. APEX, at its core, provides a best-effort datagram service. Each datagram, simply termed "data", is originated and received by APEX "endpoints" -- applications that dynamically attach to the APEX "relaying mesh".
APEX is specified, in part, as a BEEP "profile". Accordingly, many aspects of APEX (e.g., authentication) are provided within the BEEP core.
| MAC header | IP header | TCP header | BEEP | APEX message | 
APEX reply codes:
| Code | Description | 
|---|---|
| 250 | Transaction successful. | 
| 421 | Service not available. | 
| 450 | Requested action not taken. | 
| 451 | Requested action aborted. | 
| 454 | Temporary authentication failure. | 
| 500 | General syntax error (e.g., poorly-formed XML). | 
| 501 | Syntax error in parameters (e.g., non-valid XML). | 
| 504 | Parameter not implemented. | 
| 530 | Authentication required. | 
| 534 | Authentication mechanism insufficient. | 
| 535 | Authentication failure. | 
| 537 | Action not authorized for user. | 
| 538 | Authentication mechanism requires encryption. | 
| 550 | Requested action not taken. | 
| 553 | Parameter invalid. | 
| 554 | Transaction failed (e.g., policy violation). | 
| 555 | Transaction already in progress. | 
RFCs:
[RFC 3340] The Application Exchange Core.
[RFC 3341] The Application Exchange (APEX) Access Service.
[RFC 3342] The Application Exchange (APEX) Option Party Pack, Part Deux!
[RFC 3343] The Application Exchange (APEX) Presence Service.
|  | Description | Glossary | RFCs | Publications | Obsolete RFCs |