The Diameter Routing Function and invoked DSR Applications record detailed information about each Diameter transaction - called transaction metadata. Each metadata record describes an important event in the lifetime of a Diameter transaction. Metadata appears in the Trace Transaction Record (TTR) in the order that the metadata-generating events actually occurred. Together, all of the metadata records combine to document the processing performed on the entire transaction, and can later be used to provide diagnostic information when performing troubleshooting. Metadata is recorded to a TTR for each transaction so that, even if the transaction is selected to be sent to IDIH at an Answer Troubleshooting Trigger Point (TTP-IA or TTP-EA), the metadata for all of the messages in the transaction will be present.
PCA will record the Application-specific metadata events described in Table 1.
| Event | Instance Data | When Recorded |
|---|---|---|
| PCA Function Invoked | PCA Function Name | When an application with multiple functionality receives an ingress Diameter message (including both requests and answers) and routes it to one of its functions for processing Note: This metadata is only recorded if the application function is enabled and available processing messages.
|
| PCRF Pool Selected |
|
When P-DRA receives a binding-capable session initiation request |
| Binding Query Request Sent |
|
When P-DRA sends a "Find or Create Binding" stack event to a SBR |
| Binding Query Result Received |
|
When P-DRA receives a "Find or Create Binding Result" stack event from a SBR |
| Topology Hiding Applied | N/A | When P-DRA receives a bind-capable or binding-dependent session initiation/in-session answer destined for a peer for which topology hiding is configured |
| Create Session Request Sent |
|
When P-DRA sends a "Create Session" stack event to a SBR |
| Create Session Result Received |
|
When P-DRA receives a "Create Session Result" stack event from a SBR |
| Update Binding Request Sent |
|
When P-DRA sends an "Update Binding" stack event to a SBR |
| Update Binding Result Received |
|
When P-DRA receives an "Update Binding Result" stack event from a SBR |
| Find Binding Request Sent |
|
When P-DRA sends a "Find Binding" stack event to a SBR |
| Find Binding Result Received |
|
When P-DRA receives a "Find Binding Result" stack event from a SBR |
| Refresh Session Request Sent | Session ID | When P-DRA sends a "Refresh Session" stack event to a SBR |
| Refresh Session Result Received |
|
When P-DRA receives a "Refresh Session Result" stack event from a SBR |
| Delete Session Request Sent | Session ID | When P-DRA sends a "Remove Session" stack event to a SBR |
| Delete Session Result Received |
|
When P-DRA receives a "Remove Session Result" stack event from a SBR |
| Find Session Request Sent | Session ID | When P-DRA sends a "Find Session" stack event to a SBR |
| Find Session Result Received |
|
When P-DRA receives a "Find Session Result" stack event from a SBR |
| Remove Suspect Binding Request Sent |
|
When P-DRA sends a "remove Suspect Binding" stack event to a SBR |
| Remove Suspect Binding Result Received |
|
When P-DRA receives a "Remove Suspect Binding Result" stack event from a SBR |
| Session Release Initiated | Application Name | When an "Update Binding" request, a "Create Session" request or, a "Create Alternate Key" request fails |
| Session Query Initiated | Application Name | When a stale Gx session is detected by a SBR |
| Routing Exception |
|
After any routing exception is encountered |
| SBR Request Failure |
|
When a PCA Function fails to send a request to the SBR |
| SBR Response Timeout |
|
When a PCA Function times out waiting to receive a response from a SBR for a previous request |
| Routing Error Indication Received | Routing Error | When a PCA Function initiates a Diameter request (Session Release RAR) that is rejected by DRL due to a routing error. Note: The Routing Error recorded is the Error-Message AVP value of the Answer message initiated by DRL.
|
| Create OC Session Request Sent |
|
When OC-DRA sends a "Create OC Session" stack event to the Session SBR |
| Create OC Session Result Received |
|
When OC-DRA receives a "Create OC Session Result" stack event from the Session SBR |
| Find and Refresh OC Session Request Sent | Session ID | When OC-DRA sends a "Find and Refresh OC Session" stack event to the Session SBR |
| Find and Refresh OC Session Result Received |
|
When OC-DRA receives the "Find and Refresh OC Session Result" stack event from the Session SBR |
| Find and Remove OC Session Request Sent | Session ID | When OC-DRA sends a "Find and Remove OC Session" stack event to the Session SBR |
| Find and Remove OC Session Request Received |
|
When OC-DRA receives the "Find and Removed OC Session Result" stack event from the Session SBR |
The metadata captured by IDIH for the PCA includes the results of each query that PCA makes to the session and binding database and the associated result. Whenever the result of a database query is captured in PCA metadata, it will include the identity of the specific server that generated the response.
The following are key concepts for PCA as it relates to IDIH:
- IDIH can display traces in multiple formats (for example, two- or three-way split screen or single screen). Because it is very difficult to display all of the information in a single screen, output columns slide out of view. Sliders allow the column views to be manipulated.
- There are two basic ways to view Event and metadata information:
- A graphical display (for example, ladder and object)
- An event list, which provides a listing of events
The following examples illustrate the type and format of information that is collected and used from Policy DRA IDIH traces.
Note: Although these examples are for Policy DRA, information collected and used from Online Charging DRA IDIH traces is similar in presentation.
Event Diagram Trace - CCR Example
Update Request Policy DRA Example
Event Diagram - Hover (Mouse-over) Example