Cisco Cisco ASR 5000 トラブルシューティングガイド
Explanation
It turns out that if the call is responded to during the early stages of the setup, there is no bearer
context included in the response, and so therefore only one instance of a cause code included. An
early stage can include being rejected at the demux process level (i.e. egtpinmgr), parse error, or
incorrect Information Element (IE). But if calls are rejected in later stages, such as Diameter S6b,
Gx, Gy, etc., while being processed by sessmgr, which is the more common scenario, then a
cause code at the bearer context level is included (which effectively duplicates the main cause
code).
context included in the response, and so therefore only one instance of a cause code included. An
early stage can include being rejected at the demux process level (i.e. egtpinmgr), parse error, or
incorrect Information Element (IE). But if calls are rejected in later stages, such as Diameter S6b,
Gx, Gy, etc., while being processed by sessmgr, which is the more common scenario, then a
cause code at the bearer context level is included (which effectively duplicates the main cause
code).
Per specification the behavior of not including the bearer context is acceptable: 3GPP 29.274-a50
Section 6.1.1 clearly says that “Only the Cause information element at message level shall be
included in the response if the Cause contains a value that indicates that the request is not
accepted regardless of whether there are other mandatory or conditional information elements
defined for a given response message”. In summary, what is normally a mandatory IE becomes
optional (and so it is OK not to include it) in the case where the message level response is a
rejection.
Section 6.1.1 clearly says that “Only the Cause information element at message level shall be
included in the response if the Cause contains a value that indicates that the request is not
accepted regardless of whether there are other mandatory or conditional information elements
defined for a given response message”. In summary, what is normally a mandatory IE becomes
optional (and so it is OK not to include it) in the case where the message level response is a
rejection.
Related Information
●
●