Oracle Communications Diameter Signaling Router (DSR)
 

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In this Document

Symptoms

Cause

Solution

References

Created from <SR 3-11880728501>

Applies to:

Symptoms

It is observed that sometimes DSR does not sends first SCTP INIT message on Primary path of Multihomed Connection when configured as Initiator

Note System Impact:
This is only GUI display issue and doesn't have any signalling impact. The term
Primary and Secondary Local/Peer IP Addresses are misleading and user can
think that they are for load balancing while they are NOT as SCTP MH is
used only for redundancy and NOT used for load balancing

Cause

• While configuring the connection from SOAM GUI (Main Menu: Diameter -> Configuration -> Connections) Primary Local IP Address, Secondary Local IP Address, Primary Peer IP Address & Secondary Peer IP Address is defined.
• So, it is expected that when DSR is configured as Initiator it sends first SCTP INIT on Primary Path as per the definition in GUI.
• However sometimes it is noticed that during SCTP Initialization, DSR sends first SCTP INIT on Secondary Path while the Primary path (as configured in SOAM GUI) is up and reachable.
  1. It is determined that selection of Primary and Secondary IP path is not in control of dsr application and is done by LKSCTP in kernel.
     • The terms Primary/Secondary used in GUI has actually no meaning and it does not determines the Primary and Secondary IP Paths of Multihomed Connection.
  2. Further it was discovered that the container type change introduced in DSR 7.0 is leading to the issue, where INIT was being sent on configured secondary IP addresses.
     • In DSR 7.0, DCL started using std::unordered_set container to store the local and peer IP addresses of the connections, which stores the element based on hash value of its element and have changed the stored order with reference to they have configured.

Solution

• Bug# 22891849 has been opened to change GUI display so it does not uses the terms Primary and Secondary (and avoid confusion).

The GUI display will be changed as below for clarity:
SOAM GUI: (Main Menu: Diameter -> Configuration -> Connections)
Primary Local IP Address --> Local IP Address
Secondary Local IP Address --> Alternate Local IP Address
Primary Peer IP Address --> Peer IP Address
Secondary Peer IP Address --> Alternate Peer IP Address
This Bug is fixed in DSR Release 7.2

• Further below bug is also opened to fix the issue related to change in container type introduced in DSR 7.0

1. 1. Bug# 23033748- SCTP MH INIT is sent on configured secondary address
   2. Bug# 23033755 - patch delivery mechanism for DSR7.0.1 -SCTP MultiHom Path Priority -Bug 23033748
      • <Patch 23033755> has been created to fix this issue in DSR# 7.0 itself
      • MOP for patch application is at https://stbeehive.oracle.com/content/dav/st/DSR%20Technical%20Support%20Center%20%28DSR%20TSC%29/Public%20Documents/MOP%20LIBRARY/Orange%20FR_Prod_DSR701_Patch_23033755_MOP%20%28005%29.pdf

The container type has been already changed to std::vector in DSR 7.2 72.4.0 release with the fix of Bug #21428062 - DCL: Remove DbConnectionNodeIp table monitoring, where IPs from TransportConnection table will be considered for connection. So, the issue is present in DSR 7.0 & 7.1 releases only.

• Customers on DSR 7.0 and DSR 7.1 impacted by this issue should upgrade to DSR 7.2 and above to fix this issue.

References

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