Cisco Cisco ASR 5000
SGSN Service Configuration Procedures
▀ Configuring a Custom MME Group ID (S4 Only, Optional)
▄ SGSN Administration Guide, StarOS Release 18
Configuring a Custom MME Group ID (S4 Only, Optional)
3GPP specifications define how a GUTI allocated by an MME is translated into an old P-TMSI and old RAI when a UE
hands over to an SGSN. 3GPP specifications state that when a GUTI is mapped to an old RAI, the MME group ID
portion of the GUTI will be mapped to a Location Area Code (LAC). MME group IDs are 16-bit numbers which always
have their most significant bit set. As a result, their range is 32768 - 65535.
hands over to an SGSN. 3GPP specifications state that when a GUTI is mapped to an old RAI, the MME group ID
portion of the GUTI will be mapped to a Location Area Code (LAC). MME group IDs are 16-bit numbers which always
have their most significant bit set. As a result, their range is 32768 - 65535.
However, some operators may have already configured their networks with LACs for UTRAN and GERAN coverage in
the 32768 - 65535 range. To provide backward compatibility for such deployments, a custom list of MME group IDs
must be configured for use by both the S4-SGSN and MME products for UTRAN/GERAN and E-UTRAN handovers.
the 32768 - 65535 range. To provide backward compatibility for such deployments, a custom list of MME group IDs
must be configured for use by both the S4-SGSN and MME products for UTRAN/GERAN and E-UTRAN handovers.
Once the custom MME Group IDs have been configured, operators then can configure the S4-SGSN to use the available
custom MME Group IDs configured for both GPRS (2G) and UTRAN (3G) network services.
custom MME Group IDs configured for both GPRS (2G) and UTRAN (3G) network services.
Use the following procedure to configure the SGSN to use the custom MME Group IDs:
Step 1
Access LTE Network Global MME ID Management Database Configuration Mode.
Step 2
Specify the PLMN MCC and MNC values.
Step 3
Configure the low and high end values of the LAC range to be used.
Step 4
Access the context in which the SGSN (3G) service is configured.
Step 5
Associate the 3G service (if configured), with the MME’s Network Global MME ID Management Database that
contains the custom list of MME Group IDs.
contains the custom list of MME Group IDs.
Step 6
Access the context in which the 2G GPRS service is configured.
Step 7
Associate the 2G service, if configured, with the MME’s Network Global MME ID Management Database that contains
the custom list of MME Group IDs.
the custom list of MME Group IDs.
Example Configuration
config
lte-policy
network-global-mme-id-mgmt-db
plmn mcc <mcc_value> mnc <mnc_value> mme-group-id-range first
<low_end_of_range> last <high_end_of_range>
<low_end_of_range> last <high_end_of_range>
exit
exit
context <context_name>
sgsn-service <sgsn_service_name>
associate network-global-mme-id-mgmt-db