Diameter Signaling Router (DSR): Throttling To A Reduced Value Than Configured Maximum Egress Message Rate (Max EMR) Configured In Per Connection Egress Message Throttling (PCEMT)

Asset ID:	1-72-2173967.1
Update Date:	2016-12-14
Keywords:

Solution Type Problem Resolution Sure

Solution 2173967.1 : Diameter Signaling Router (DSR): Throttling To A Reduced Value Than Configured Maximum Egress Message Rate (Max EMR) Configured In Per Connection Egress Message Throttling (PCEMT)

Applies to:

Oracle Communications Diameter Signaling Router (DSR) - Version DSR 7.0.1 and later
Information in this document applies to any platform.

Symptoms

Customers may see lower than expected Max EMR while PCEMT is occurring.

Changes

Upgrade from DSR 5.0 to DSR 7.0.1

Cause

Egress connections sending low traffic in scenarios where the Egress Traffic has exceeded the configured Onset Threshold levels of Egress Message Throttling Configuration Set applied on the connection and the traffic subsequently drops to 0 due to congestion and ingress requests are priority 0, the threshold alarm (Event Number# 22057) would not clear until traffic resumes.
A total absence of traffic is not likely and Diameter has watch dog traffic that will eventually kick in and flush the alarm otherwise.

Solution

This issue is identified as “Bug 21365624 - CSL: metric thresholds not abating in the absence of traffic”.
This Bug is resolved in DSR 7.1 and above, it is recommended to upgrade to latest GA release.
Further it is also recommended to re-evaluate your PCEMT related timers
- Abatement Time
- Convergence Time
- Abatement Threshold Level 1/ Abatement Threshold Level 2 and Abatement Threshold Level 3
- Throttle Threshold Level 1, Throttle Threshold Level 2 and Throttle Threshold Level 3
It recommended to keep a low value for Abatement Time because it helps DSR to reduce the congestion level quickly and traffic will be allowed to flow through again until the Throttle Threshold Level is reached again and the cycle continues.
Also refer KM Doc ID 2069057.1
- Patch 24454070: Patch for Diameter Signal Routing 7.0.1.0.0-70.28.0, was also created to fix this issue on DSR 7.0.1
- MOP to apply the patch is on
https://stbeehive.oracle.com/content/dav/st/DSR%20Technical%20Support%20Center%20%28DSR%20TSC%29/Public%20Documents/MOP%20LIBRARY/OrangeFR_Prod_DSR701_Patch_24328222_MOP_%28001%29.pdf

References

<NOTE:2069057.1> - Diameter Signaling Router (DSR): Throttling To A Reduced Value Than Configured Maximum Egress Message Rate (Max EMR) Configured In Per Connection Egress Message Throttling (PCEMT) & Egress Throttling Group (ETG) Due to High Abatement Time
<BUG:21365624> - CSL: METRIC THRESHOLDS NOT ABATING IN THE ABSENCE OF TRAFFIC

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