Cisco Cisco Packet Data Gateway (PDG)
MME Changes in Release 17
MME Enhancements for 17.0 ▀
Release Change Reference, StarOS Release 17 ▄
315
CSCum37090, CSCuo78943, CSCuo78935, CSCuq60916 - MME needs to
support MME Restoration Lite
Feature Changes
MME Restoration - Standards Extension
The feature implements the Network Triggered Service Restoration (NTSR) procedures defined in 3GPP TS 23.007
Release 11 (DDN with IMSI) on the MME.
Release 11 (DDN with IMSI) on the MME.
By implementing the extensions to the standard MME restoration, the robustness of the network is greatly enhanced and
potential issues due to the MME downtime are mitigated.
potential issues due to the MME downtime are mitigated.
The solution to recover from MME node failures proposed in the 3GPP standards rely on the deployment of MME pools
where each pool services a coverage area. Following a MME failure, the S-GW and MSC/VLR nodes may select the
same MME that used to service a UE, if it has restarted, or an alternate MME in the same pool to process Network-
initiated signaling that it received in accordance with the NTSR procedures defined in 3GPP TS 23.007 Release 11.
where each pool services a coverage area. Following a MME failure, the S-GW and MSC/VLR nodes may select the
same MME that used to service a UE, if it has restarted, or an alternate MME in the same pool to process Network-
initiated signaling that it received in accordance with the NTSR procedures defined in 3GPP TS 23.007 Release 11.
Upon receipt of a DDN without any TAI list or other previously sent information from the S-GW after a MME failure or
restart, the MME shall proceed with regular IMSI-based paging.
restart, the MME shall proceed with regular IMSI-based paging.
The MME can be configured to throttle IMSI-based DDN requests as needed to maintain adequate service performance
for normal procedure processing. Refer to the
for normal procedure processing. Refer to the
network-overload-protection mme-new-connections-per-
second
below for more information.
MME/VLR Restoration Procedure Via Alternate MME
The MME now supports the Mobile Terminated CS service delivery via an alternate MME in MME pool feature
described in 3GPP TS 23.007 Section 14.1.3 & 26 and 29.118 Release 11.
described in 3GPP TS 23.007 Section 14.1.3 & 26 and 29.118 Release 11.
Upon receipt of a SGs Paging request from a VLR with CS restoration bit set, the MME will perform a regular IMSI-
based paging procedure, in the absence of any additional context information. If the CS Restoration Indicator is set, the
MME shall page the UE regardless of the value of MME-Reset indicator. The location information shall be set in
accordance with the existing procedures for unknown UE with the MME-Reset indicator set to TRUE.
based paging procedure, in the absence of any additional context information. If the CS Restoration Indicator is set, the
MME shall page the UE regardless of the value of MME-Reset indicator. The location information shall be set in
accordance with the existing procedures for unknown UE with the MME-Reset indicator set to TRUE.
No special configuration is needed to enable this functionality.
ULA for Periodic TAU when VLR Inaccessible
When processing a periodic TAU request from a UE, if the MME detects that the VLR serving the UE is inaccessible,
the MME now selects an alternative VLR that is in service for the UE and performs a location update for non-EPS
services procedure towards the selected VLR.
the MME now selects an alternative VLR that is in service for the UE and performs a location update for non-EPS
services procedure towards the selected VLR.
The MME previously supported this functionality in case of non-periodic TAU.
Command Changes
gtpc node-feature network-triggered-service-restoration
This command includes the new
network-triggered-service-restoration
keyword to enable NTSR
functionality for this EGTP service.
configure