Cisco Cisco Packet Data Gateway (PDG) Veröffentlichungshinweis
MME Changes in Release 15.0
▀ MME Enhancements for September 30, 2013
▄ Cisco ASR 5x00 Release Change Reference
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New Behavior: In this release, an additional configuration option allows the operator to indicate a list of served
MMECs, in addition to the one assigned to the MME service. The complete list is notified to the eNodeB as Served
MMECs in the S1 Setup Response. This aids the eNodeB in selecting a collocated MME during 3G to 4G handover
events.
MMECs, in addition to the one assigned to the MME service. The complete list is notified to the eNodeB as Served
MMECs in the S1 Setup Response. This aids the eNodeB in selecting a collocated MME during 3G to 4G handover
events.
Refer to the
inter-rat-nnsf
command in the Modified MME Commands section for more information.
New SNMP Notifications
In Release 14.0, new SNMP traps were added to track the availability of VLR associations.
(VLRAllAssocDown/VLRAllAssocDownClear and VLRAssocUP/VLRAssocDown), where:
(VLRAllAssocDown/VLRAllAssocDownClear and VLRAssocUP/VLRAssocDown), where:
VLRAssocDown - is sent when an association of a VLR is down.
VlrAllAssocDown - is sent when all associations of all VLRs are down.
In this release, two new traps are added to indicate a condition where all SCTP associations to a specific VLR are down
(VLRDown) and when a down VLR comes back up (VLRUp).
(VLRDown) and when a down VLR comes back up (VLRUp).
starVLRUp
starVLRDown
Two new SNMP traps have been introduced in this release to indicate a condition when new MME call are being
rejected or dropped, and when this condition has been cleared and the MME is accepting new calls again.
rejected or dropped, and when this condition has been cleared and the MME is accepting new calls again.
starMMENewConnectionsDisallowed
starMMENewConnectionsAllowed
In the MME, new connections are setup for the following events
UE initiated initial attach
UE initiated inter-node TAU request requiring context transfer from old MME/SGSN
Peer SGSN/MME initiated forward relocation request via Gn/S10/S3
Note that the congestion control feature generates its own set of traps to indicate/clear a congestion condition. However,
if new connections are being disallowed due to congestion, both sets of traps may be generated.
if new connections are being disallowed due to congestion, both sets of traps may be generated.
S-GW Change Fallback Enhancements
Previous Behavior: In previous releases, the MME supported S-GW reselection and fallback if path-failure was
detected while waiting for S11 create session response during initial attach procedure. S-GW fallback was not supported
during any other procedures.
detected while waiting for S11 create session response during initial attach procedure. S-GW fallback was not supported
during any other procedures.
New Behavior: This feature has been enhanced to add detection of S-GW failure, and reselection and fallback for the
S11 Create Session Response for S-GW relocation during X2 Handover, S1 Handover, and Idle mode Tracking Area
Update procedures.
S11 Create Session Response for S-GW relocation during X2 Handover, S1 Handover, and Idle mode Tracking Area
Update procedures.
If DNS returns more than one S-GW candidate, and the MME sends Create Session Requests for all of the PDNs to the
first S-GW and receives either no response or a failed response from the S-GW (meaning the CS bit in the Cause IE is
set to 0) for all of the PDNs, the MME will then try sending Create Session Requests for all PDNs to the second S-GW.
The MME will continue trying all candidate S-GWs until one of the following conditions are met:
first S-GW and receives either no response or a failed response from the S-GW (meaning the CS bit in the Cause IE is
set to 0) for all of the PDNs, the MME will then try sending Create Session Requests for all PDNs to the second S-GW.
The MME will continue trying all candidate S-GWs until one of the following conditions are met:
1. A successful Create Session Response is received for at least one of the PDNs.
2. A failed Create Session Response is received from the P-GW (meaning the CS bit in the Cause IE is set to 1) for at
least one of the PDNs.
least one of the PDNs.