TMSI Based NRI Container IE

Feature Summary and Revision History

Summary Data

Applicable Product(s) or Functional Area

MME

Applicable Platform(s)

  • ASR 5500

  • VPC-DI

Feature Default

Disabled - Configuration Required

Related Changes in This Release

Not Applicable

Related Documentation

  • Command Line Interface Reference

  • MME Administration Guide

  • Statistics and Counters Reference

Revision History

Revision Details

Release

TMSI based NRI container IE in LUR message over SGs interface is supported.

21.28

Feature Description

MME supports Temporary Mobile Subscriber Identity (TMSI) based Network Resource Identifier (NRI) container IE in the Location Update Request (LUR) message over SGs interface. The UE sends this IE through the Combined Attach or Tracking Area Update (TAU) Request message. After the IE gets received, it gets parsed, processed, and sent through the SGs interface to the Visitor Location Register (VLR) in the LUR message.

How it Works

UE sends IE value to MME through S1Ap interface. The value is sent either in the Combined Attach or the TAU request. Now, MME sends the value in the LUR message to the VLR.

If UE does not send TMSI based NRI container in the Combined Attach or the TAU Request message, and if MME determines that the serving VLR changed for UE, MME includes the non-broadcasted Location Area Indentifier (LAI) in the old LAI field of the LUR message. Using the below mentioned configurations, the non-broadcasted LAI can be configured, which will be included in LUR message if serving VLR changed for the UE.

Table 1. LUR Content Based on the TMSI Based NRI Container IE Value and Serving VLR Change

Sl. No

IEs present in the Combined Attach or TAU message

MME deducts change in serving VLR

Resultant LUR content

Non-braodcast LAI CLI Content used

1

TMSI-based NRI container IE, old LAI IE

yes

TMSI-based NRI container IE, old LAI

No

No

TMSI-based NRI container IE, old LAI

No

2

 TMSI-based NRI container IE, no old LAI IE

Yes

TMSI-based NRI container IE

No

No

TMSI-based NRI container IE

No

3

No TMSI-based NRI container IE, old LAI IE

Yes

Non-broadcast LAI

For more information, refer the Note.

Yes

No

Old LAI

No

4

No TMSI-based NRI container IE, no old LAI IE

Yes

Non-broadcast LAI

For more information, refer the Note.

Yes

No

No IE

No

Note
Sending the 'Non-broadcast LAI' in Location Update Request (LUR) applies to TAU scenarios where the MME can detect VLR changes. This doesn't apply to attach scenarios because the MME lacks prior VLR context due to detachment.

Configuring NonBroadcast LAI

Use the following configuration to configure nonbroadcast lai.

configure 
  context context_name 
    sgs-service service_name 
      [ no ] lai non-bradcast mcc mcc_id mnc mnc_id lac lac_id 
  end

NOTES:

  • no : Removes the nonbroadcast LAI configuration.

  • lai non-broadcast : Specifies the Location Area Identity (LAI), not assigned to any area.

  • mcc mcc_id : Configures the mobile country code (MCC). mcc_id is a 3-digit number between 000 to 999.

  • mnc mnc_id : Configures the mobile network code (MNC). mnc_id is a 2- or 3-digit number between 00 to 999.

  • lac lac_id : Configures the location area code (LAC). lac_id is an integer from 0 to 65535.

Monitoring and Troubleshooting

This section provides information on how to monitor and troubleshoot using show commands to support this feature.

Show Commands and Output

This section provides information regarding show commands and their outputs for this feature.

show sgs-service all

The output of this command is enhanced to display the following fields.

Table 2. show sgs-service all Command Output Descriptions
Field Description

Non-Broadcast LAI

MCC

Displays the configured MCC value.

MNC

Displays the configured MNC value.

LAC

Displays the configured LAC value.