Satsite Core Backup Feature

This guide will introduce you to the Satsite Core Backup feature, how to configure and use it.

About Satsite Core Backup feature

When you have two cores and you want to use one of them (Main Core) and keep the other one as hot-standby that the Basestations can use it when the main core is unreachable.

In this guide, when the Basestation is moving to the backup core its referred to as (Switched to the backup). When the Basestation registers back to the main core this is referred to as (Fallback).

This feature can enable automatic fallback to the main core when its up under the following conditions:

  1. The switch to the core happened since 10 minutes or more (To avoid fast flapping between cores)
  2. The original core is reachable with less than 10% ping loss for one minute. 
  3. For LTE, if the S1AP link failed for any reason other than IP connectivity, the automatic fallback will be disabled. (As it’s not possible to confirm the issue has been resolved without interrupting the service).


For LTE

Checking the link to the main MME depends on the S1AP link from eNodeB itself; if eNodeB cannot register to the MME due to invalid PLMN this will be considered as reachability problem. Regardless of the reason for S1AP it will try to switch to the backup MME.

Restrictions:

  1. If you have Load Balance feature active, Core Backup will not check the link status.
  2. If S1AP link is down due to any reason other than IP connectivity, the fallback will be disabled.


For GSM

Checking the link to the core is depending on the IP connectivity only. If the registration fails for any other reason it won’t be detected.

Monitoring

It’s possible to have a trigger on Zabbix when the backup core is in use.

 

Requirements

  • Satsite Hardware
    This feature is not supported in Labkits.
  • The following rpms:
  • satsite_utilities-1-1_8376_svn.mga5.x86_64.rpm
  • yate-sdr-1.1-1_r222_r488_8382_svn.mga5.noarch.rpm
  • yate-enb-1.0.0-8384svn0_prot.mga5.x86_64.rpm
  • To use it with Zabbix, Zabbix 4.0 or newer is required.

Configuration for LTE

To enable Core Backup for eNodeB, please follow these steps:

  1. Make sure you have the minimum software requirements.
  2. Open the file /etc/yate/sdr/satsite-sw.conf
  3. In the LTE section, edit:
    1. Backup MME IP -> MME_backup=
    2. eNodeB IP address -> local_MME_backup=
    3. eNodeB IP for GTP -> local_GTP_backup=
  4. If you want eNodeB to fallback to the original MME (under some conditions) enable the option -> fallback=yes
  5. Make sure the service is enabled (systemctl status satsite-sw.service)

SatSite
20W basestation for GSM & LTE (eNodeB), operating in multiple GSM/LTE bands
See the product here ››

Configuration for GSM

To enable Core Backup for BTS, please follow these steps:

  1. Make sure you have the minimum software requirements.
  2. Open the file /etc/yate/sdr/satsite-sw.conf
  3. In the GSM section, edit:
    1. Backup Core IP -> sip_backup=  (If you wish to use customized port, kindly use the format sip_backup=IP:Port
    2. BTS local backup IP -> local_sip_backup=
  4. If you want BTS to fallback to the original SIP  enable the option -> fallback=yes
  5. Make sure the service is enabled (systemctl status satsite-sw.service)

Checking the logs

While the service is running it adds the logs to /var/log/satsite-sw.log
You can run the service in debug level by editing the file /etc/yate/sdr/satsite-sw.conf and put -> debug=yes. 
Please note that
  1. Debugs are disabled by default.
  2. logrotate is controlling this log for 10M and 5 rotates by default.

Monitoring with Zabbix

It’s possible to Monitor when the Basestation has switched to the backup core using Zabbix.

Please follow these steps:

  1. Make sure you have basic configurations. Kindly refer to Zabbix Monitoring for Basestation
  2. Add the template (yate-satsite)

When the switch happens it will show a trigger (Satsite has switched to the backup core) in warning level.

This trigger will autoresolve itself if the Basestation fallback to the initial Core.

SatSite eNodeB Core Backup feature in Zabbix