Oracle Communications Diameter Signaling Router (DSR)
 

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In this Document

Symptoms

Changes

Cause

Solution

References

Created from <SR 3-15404587761>

Applies to:

Symptoms

Diameter connection or connections configured in the DSR as responder and using a specific IPFE TSA show instability particularly if newly configured or experiencing low traffic.  The connection is terminated with RST (if TCP) or ABORT (if SCTP), generally after Device Watchdog message or other traffic forwarded from IPFE to a different host DA-MP than expected for the connection.  Although it can occur for both transport protocols, this condition is more likely to be observed for a TCP connection than for a multi-homed SCTP connection.

Changes

 Any of these changes may have been recently imposed:

- The Connection is new or recently taken offline and configuration altered to use new Target Set Address.
- The Target Set Address entry is new or recently edited to utilize new values.
- The Connection Configuration Set is newly assigned to this Connection or recently had Watchdog values changed.

Cause

 The IPFE Target Set's Delete Age value is set too low.

Solution

For each configured IPFE Target Set Address, a parameter known as Delete Age governs the length of time an association remains known to the IPFE.  The default value for this parameter is 600s (10min) but can be edited to any value between 10s and 3110400s (36 days).  It is generally recommended to leave the value at default for most connections, but the value MUST be larger than the Device Watchdog interval (initial value from DSR side is set to 30s but is also an edit-able parameter in the Connection Configuration Set).  If altering, the minimum recommended value is no less than 2x the smallest Device Watchdog interval on the connection, which is not exclusively governed by DSR side.

The Solution to the problem in this Article is to check the Delete Age for the TSA(s) in use for the Connection and ensure the value is set sufficiently high for the Device Watchdog interval and/or traffic frequency.  The Delete Age can be found via SOAM GUI -> Main Menu -> IPFE -> Configuration -> Target Sets [Edit], or you can export the IPFE configuration and look in the IPFE Options file to see the value for the TSA.  The Device Watchdog interval value may not be so easily defined or identified, as both ends of the connection are capable of initiating watchdog message exchange and the intervals may not be a fixed value.  Thirty seconds is a typical default or average value.

Reference the Diameter Signaling Router IP Front End (IPFE) User's Guide for more information on Delete Age.  The document sets are available on docs.oracle.com.

References

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