Cisco Cisco Packet Data Interworking Function (PDIF)
MME Changes in Release 16
MME Enhancements for 16.4 ▀
Release Change Reference, StarOS Release 16 ▄
217
Previous Behavior: By default, when a UE was in connected state with an MME and whenever the MME received a
TAU Request over Initial-UE, then the MME initiated a UE-CONTEXT-RELEASE with cause NAS-Unspecified.
TAU Request over Initial-UE, then the MME initiated a UE-CONTEXT-RELEASE with cause NAS-Unspecified.
New Behavior: Now, by default, an MME initiates the UE-CONTEXT-RELEASE with cause NAS-Normal-Release
whenever the MME receives a TAU Request over Initial-UE if the UE is in the connected state. As well, the CLI has
been changed to enable the operator to configure a preferred cause code for init-ue-from-enodeb-for-tau.
whenever the MME receives a TAU Request over Initial-UE if the UE is in the connected state. As well, the CLI has
been changed to enable the operator to configure a preferred cause code for init-ue-from-enodeb-for-tau.
Customer Impact: This change only impacts a customer if the customer update their KPI calculation based on this
cause.
cause.
Command Changes
s1-ue-context-release
This new CLI command enables the operator to specify the cause code to be sent in UE-CONTEXT-RELEASE initiated
by the MME upon the reception of TAU Request over INITIAL-UE message when a UE is in connected state.
by the MME upon the reception of TAU Request over INITIAL-UE message when a UE is in connected state.
configure
context context_name
mme-service service_name
s1-ue-context-release reason init-ue-from-enodeb-for-tau cause type { nas
value nas_value | radio value radio_value }
value nas_value | radio value radio_value }
default s1-ue-context-release reason init-ue-from-enodeb-for-tau cause
end
Notes:
This CLI enables the operator to configure the MME cause code mapping to be sent in a UE-CONTEXT-
RELEASE message initiated from MME due to the reception of TAU procedure on Initial-UE message from
the same eNB or from a different eNB. The configured cause code will be sent in the UE-CONTEXT-
RELEASE message whenever MME releases the existing S1AP connection upon receiving a TAU procedure
in an Initial-UE message.
the same eNB or from a different eNB. The configured cause code will be sent in the UE-CONTEXT-
RELEASE message whenever MME releases the existing S1AP connection upon receiving a TAU procedure
in an Initial-UE message.
Currently, the only release reason possible is ‘init-ue-from-enodeb-for-tau’.
There are two cause options for which cause code values can be assigned:
nas value nas_value
options are:
0 - Normal Release (default value)
1 - Authentication Failure
2 - Detach
3 - Unspecified
4 - CSG Subscription Expiry
radio value radio_value
must be an integer from 0 to 38.