Cisco Cisco Packet Data Gateway (PDG)
MME Changes in Release 17
MME Enhancements for 17.7 ▀
Release Change Reference, StarOS Release 17 ▄
239
CSCux33388, CSCur41900 - CLI Control for Target Access Restriction
CSCux33388 - InterSGSN 3G to 2G HO fails
CSCur41900 -Rollback Behavior in EPC during TAU/RAU Needs to be Corrected
Feature Changes
Target Access Restriction
Target Access Restriction feature was added to the SGSN and MME in release 17.4. The purpose of this feature is to
avoid rollback behavior that exists in RAU and TAUs by checking target RAT Type IE present in the Context Request
at the source node, and then rejecting the TAU/RAU based on the subscriber’s ARD profile earlier in the cycle if the
target RAT is restricted for the subscriber. Rollback behavior caused late TAU/RAU rejection, resulting in PDP/bearer
deletion for the MME, PGW, and the SGSN, requiring the UE to reattach and reactivate lost PDP/bearer.
avoid rollback behavior that exists in RAU and TAUs by checking target RAT Type IE present in the Context Request
at the source node, and then rejecting the TAU/RAU based on the subscriber’s ARD profile earlier in the cycle if the
target RAT is restricted for the subscriber. Rollback behavior caused late TAU/RAU rejection, resulting in PDP/bearer
deletion for the MME, PGW, and the SGSN, requiring the UE to reattach and reactivate lost PDP/bearer.
Previous Behavior: As a part of this functionality, the target access restriction feature instructs the source-SGSN or the
source-MME to reject outbound RAU when the target access was restricted for the subscriber. Rejection was performed
without checking "access-restriction-data no-check" in the call control profile configuration.
source-MME to reject outbound RAU when the target access was restricted for the subscriber. Rejection was performed
without checking "access-restriction-data no-check" in the call control profile configuration.
New Behavior: With release 17.6.1, a new command keyword
target-access-restriction
has been introduced
to the call control profile configuration to control (enable/disable) target access restriction functionality. Target access
restriction is now disabled by default on both the SGSN and the MME. Refer to the Command Changes section below
for the command information to enable/disable this functionality.
restriction is now disabled by default on both the SGSN and the MME. Refer to the Command Changes section below
for the command information to enable/disable this functionality.
The default behaviors for the SGSN and the MME now differ:
New Behavior for the MME only:“target-access-restriction” keyword configuration will control the target
access restriction feature for the MME without other consideration:
No Rejection: if “target-access-restriction” is not enabled, then the source-MME will not reject the
outbound RAU Request based on the ARD profile of the subscriber per the Access-Restriction-Data
received in ULA/ULR using the RAT Type IE received in the Context Request.
received in ULA/ULR using the RAT Type IE received in the Context Request.
Rejection: if “target-access-restriction” is enabled, then the source-MME will reject the outbound RAU
Request based on the ARD profile of the subscriber per the Access-Restriction-Data received in
ULA/ULR using the RAT Type IE received in the Context Request.
ULA/ULR using the RAT Type IE received in the Context Request.
New Behavior for the SGSN only:"target-access-restriction" keyword configuration enables/disables the target
access restriction feature. The SGSN also considers "access-restriction-data no-check" in the call control
profile configuration prior to rejecting outbound RAU when target access restriction functionality is enabled.
The SGSN’s target access restriction behavior is dependent upon the SGSN’s “access-restriction-data no-
check” configuration:
profile configuration prior to rejecting outbound RAU when target access restriction functionality is enabled.
The SGSN’s target access restriction behavior is dependent upon the SGSN’s “access-restriction-data no-
check” configuration:
No Rejection: if “target-access-restriction” is enabled, and if “access-restriction-data no-check” is
enabled, then the source-SGSN will not reject the outbound RAU Request based on the ARD profile
of the subscriber per the Access-Restriction-Data received in ULA/ULR using the RAT Type IE
received in the Context Request.
of the subscriber per the Access-Restriction-Data received in ULA/ULR using the RAT Type IE
received in the Context Request.
Rejection: if “target-access-restriction” is enabled, and if “access-restriction-data no-check” is not
enabled, then the source-SGSN will ignore the “target-access-restriction enabled” configuration and
the source-SGSN will reject the outbound RAU Request based on the ARD profile of the subscriber
per the Access-Restriction-Data received in ULA/ULR using the RAT Type IE received in the
Context Request.
the source-SGSN will reject the outbound RAU Request based on the ARD profile of the subscriber
per the Access-Restriction-Data received in ULA/ULR using the RAT Type IE received in the
Context Request.