Oracle Communications Diameter Signaling Router (DSR)
 

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In this Document

Goal

Solution

References

Created from <SR 3-11202603591>

Applies to:

Goal

The Goal of this document is to understand why Info EventId 22701 "Protocol Error in Diameter Answer" indicating "AuthApplicationId AVP is missing" may be raised when the DSR PCA application receives RAA with no Auth-ApplicationId AVP.  The document also explains plans to remove the generation of this Event in future releases.

Please note that DSR may generate this 22701 Event for other conditions; validate conditions to determine if this article applies.

Solution

Background:
==========
The 3GPP spec has conflicting sections regarding the required content of RAA messages.  The internal Oracle DSR design documentation takes the following statements in 3GPP TS 29.212 (v13.2.0 2015-06) as the guide for Auth-Application-Id AVP inclusion:

                    [Chapter 5 Gx protocol, Section 5.1 Protocol support]
                    Due to the definition of the commands used in Gx protocol, there is no possibility to skip the
                    Auth-Application-Id AVP and use the Vendor-Specific-Application-Id AVP instead. Therefore the
                    Gx application identification shall be included in the Auth-Application-Id AVP.

                    [Chapter 5 Gx protocol, Section 5.6 Gx Messages, Subsection 5.6.1 Gx Application]
                    Due to the definition of these commands there is no possibility to skip the Auth-Application-Id AVP
                    and use the Vendor-Specific-Application-Id AVP instead. Therefore the Gx application identifier
                    shall be included in the Auth-Application-Id AVP.

It has been pointed out that section 5.6.5 of the same document does not include the Auth-Application-Id AVP in the message construction.  This creates a conflict with the statements in the preceding sections of the TS.

                    5.6.5 Re-Auth-Answer (RAA) Command
                    The RAA command, indicated by the Command-Code field set to 258 and the 'R' bit cleared in the
                    Command Flags field, is sent by the PCEF to the PCRF in response to the RAR command.
                    Message Format:
                    <RA-Answer> ::=  < Diameter Header: 258, PXY >
                    < Session-Id >
                    { Origin-Host }
                    { Origin-Realm }
                    [ Result-Code ]
                    [ Experimental-Result ]
                    [ Origin-State-Id ]
                    [ OC-Supported-Features ]
                    [ OC-OLR ]
                    [ IP-CAN-Type ]
                    [ RAT-Type ]
                    [ AN-Trusted ]
                     0*2 [ AN-GW-Address ]
                    [ 3GPP-SGSN-MCC-MNC ]
                    [ 3GPP-SGSN-Address ]
                    [ 3GPP-SGSN-Ipv6-Address ]
                    [ RAI ]
                    [ 3GPP-User-Location-Info ]
                    [ User-Location-Info-Time ]
                    [ NetLoc-Access-Support ]
                    [ User-CSG-Information ]
                    [ 3GPP-MS-TimeZone ]
                    [ Default-QoS-Information ]
                    *[ Charging-Rule-Report]
                    [ Error-Message ]
                    [ Error-Reporting-Host ]
                    *[ Failed-AVP ]
                    *[ Proxy-Info ]
                    *[ AVP ]

Present Status, DSR7.x:
===================
Currently in DSR7.0.x on receipt of a Diameter Answer message without mandatory [as interpreted when designed] Auth-Application-Id AVP present, DSR PCA application will generate Event 22701 but continue processing the message using the Auth-Application-Id from the corresponding Request.  This event is level 'INFO' rather than MN/MJ/CR alarm and is meant for informational purposes only.  The event can be ignored; there is no signaling or other operational impact to the network or the DSR.


Planned Changes:
===================
Due to the conflict in the TS sections and apparent difference in RAA content from vendors, until the 3GPP spec makes clear the intended content there is no benefit from generating the INFO event for this case.  Oracle has concluded that a code change should be pursued to remove the appearance of any 22701 ("Protocol Error in Diameter Answer") events for this case.  This change will appear in a future DSR software release.

Please note that DSR may generate this 22701 Event for other conditions; validate conditions to determine if this article applies.  This article is specific to RAA messages.

References

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