- About this Guide
- Mobility Management Entity Overview
- Mobility Management Entity Configuration
- 128K eNodeB Connections
- A-MSISDN Functionality
- Access Restriction based on Regional Zone Code
- APN Override
- Backup and Recovery of Key KPI Statistics
- Cause Code #66
- Cell Broadcast Center - SBc Interface
- Cell Traffic Trace
- Closed Subscriber Groups
- CSFB and SMS over SGs Interface
- CSFB for 1xRTT
- DDN Throttling
- Default APN for DNS Failure
- eDRX Support on the MME
- Emergency Bearer Services
- Enhanced Congestion Control and Overload Control
- Enhanced Multimedia Priority Service (eMPS)
- Enhanced Event Logging
- Foreign PLMN GUTI Management
- GTP-C Load and Overload Control on MME
- GUTI Re-allocation
- Heuristic and Intelligent Paging
- HSS-based P-CSCF Restoration
- Idle-mode Signaling Reduction
- IMSI Manager Overload Control
- IMSI Manager Scaling on the MME
- Integrity and Confidentiality Algorithms for UE
- IPNE Service
- Limiting the Number of SGWs Tried
- Load Balancing and Rebalancing and VoLTE Offloading
- Local Emergency Numbers List
- Location Services
- MBMS for MME (eMBMS)
- Operator Policy
- Operator Specific QCI
- Operator Policy Selection Based on IMEI-TAC
- Overcharging Protection
- Paging Priority IE Support
- Power Saving Mode (PSM) in UEs
- QoS Profile Support
- S13 Additional IMEI Check
- Selective Authentication
- Session Tracing
- SGW Blacklisting on the MME
- SGSN-MME Combo Optimization
- Single Radio Voice Call Continuity
- SRVCC for 1xRTT
- State-Location Information Retrieval Flag
- TAI-based Routing for 20-bit and 28-bit eNB ID
- Timer-based GBR Bearer Deactivation
- UDPC2 Support for MME/SGSN
- UE Relocation
- VLR Management
- Troubleshooting the MME Service
- Monitor the MME Service
- Engineering Rules
Engineering
Rules
This section provides engineering rules or guidelines that must be considered prior to configuring the system for your network deployment.
Service Engineering Rules
The engineering rules listed here apply to the services configurations for the MME system.
-
A maximum combined total of 256 services (regardless of type) can be configured per system. Important: Maintaining a large number of services increases the complexity of management and may impact overall system performance (i.e., resulting from such things as system handoffs). Therefore, we recommend that you limit the number of services that you configure and that you talk to your Cisco Service Representative for optimization suggestions and additional information on service limits.
-
The total number of entries per table and per chassis is limited to 256.
-
Of the 256 possible services, the MME supports a maximum total combination of eight (8) MME-specific services, of the types MME + eMBMS + SGs+ SBc + SLs -service, be configured per chassis.
-
The maximum number of HSS Peer Services that can be created and configured is 64 HSS Peer Services per MME chassis.
Important: In some cases, two diameter endpoints (S6a and S13) can be configured for a single HSS Peer Service. To ensure peak system performance, we recommend that the total of all Diameter endpoints should be taken into consideration and limited to 64 endpoints.
-
We strongly recommend that service names be unique across the chassis/system configuration. Even though service names can be identical to those configured in different contexts on the same system, this is not a good practice. Having services with the same name can lead to confusion, difficulty troubleshooting problems, and make it difficult to understand the outputs of show commands.
Node Engineering Rules
The following engineering rules apply regarding the number of nodes supported on the system.
eNodeBs:
-
In Release 18 .0 and higher, the MME supports a maximum of 32,000 eNodeB connections on the ASR5000 platform and a maximum of 64,000 eNodeB connections on the ASR5500 DPC platform, with a fully loaded system (chassis).
-
In Release 19.2, the MME supports a maximum of 64,000 eNodeB connections on the ASR5500 DPC2 platform with a fully loaded system (chassis).
-
In Release 20.0, the MME supports a maximum of 128, 000 eNodeB connections on the ASR5500 DPC2 platform with a fully loaded system (chassis).
Release 17.0 and higher:
Previous Releases:
MME Managers
-
In Release 17.0, The maximum number of MME Managers has been increased to 16 in order to support the increase in eNodeB connections.
-
In Release 18.0, the maximum number of MME Managers is 12 on the ASR5000 platform and increased to 24 on the ASR5500 DPC platform, in order to support the increase in eNodeB connections.
-
In Release 19.2, the maximum number of MME Managers is increased to 36 on the ASR5500 DPC2 platform, in order to support the increase in eNodeB connections.
MME Task Instance Limit
This section describes the task instance limit for MME managers and IMSI managers.
Platform |
Default number of MME Managers per Chassis |
Maximum number of MME Managers per Chassis |
||||
---|---|---|---|---|---|---|
StarOS Release |
v19.2 |
v20.0 |
v21.0 |
v19.2 |
v20.0 |
v21.0 |
ASR5000 |
12 |
12 |
12 |
12 |
12 |
12 |
ASR5500 with DPC |
24 |
24 |
24 |
24 |
24 |
24 |
ASR5500 with DPC2 |
36 |
36 |
48 |
36 |
36 |
48 |
VPC-SI MEDIUM/LARGE |
2 |
2 |
2 |
2 |
2 |
2 |
VPC-SI SMALL, VPC-SI FORGE |
1 |
1 |
1 |
1 |
1 |
1 |
VPC-DI MEDIUM/LARGE |
24 |
48 |
48 |
24 |
48 |
48 |
ASR5700 |
24 |
24 |
24 |
24 |
24 |
24 |
Platform |
Default number of IMSI Managers per Chassis |
Maximum number of IMSI Managers per Chassis |
||||
---|---|---|---|---|---|---|
Release |
v19.2 |
v20.0 |
v21.0 |
v19.2 |
v20.0 |
v21.0 |
ASR5000 PSC/PSC2/PSC3 |
1 |
1 |
1 |
1 |
1 |
1 |
ASR5500 with DPC |
4 |
4 |
4 |
4 |
4 |
4 |
ASR5500 with DPC2 |
4 |
4 |
8 |
4 |
4 |
8 |
VPC-SI MEDIUM/LARGE |
1 |
1 |
1 |
1 |
1 |
1 |
VPC-SI SMALL, VPC-SI FORGE |
1 |
1 |
1 |
1 |
1 |
1 |
VPC-DI MEDIUM/LARGE |
4 |
4 |
4 |
4 |
4 |
4 |
ASR5700 |
4 |
4 |
4 |
4 |
4 |
4 |
APN Engineering Rules
The following engineering rules apply to APN configuration on the MME: