The sip:provider CE system upgrade to mr3.5.1 will be performed in a couple of tasks:

For upgrading the sip:provider CE to release mr3.5.1, execute the following commands:

NGCP_CURRENT_VERSION=$(cat /etc/ngcp_version)
sed -i "s/$NGCP_CURRENT_VERSION/mr3.5.1/" /etc/apt/sources.list.d/sipwise.list
apt-get update
apt-get install ngcp-upgrade-mr3.5.1-ce

	sip:provider CE can be upgraded to mr3.5.1 from previous release or previous build only, otherwise you will get an error "Unable to locate package ngcp-upgrade-mr3.5.1-ce" (in this case, you need to upgrade sip:provider CE to previous release first).

Run the upgrade script as root like this:

ngcp-upgrade

The upgrade script will ask you to confirm that you want to start. Read the given information carefully, and if you agree, proceed with y.

The upgrade process will take several minutes, depending on your network connection and server performance. After everything has been updated successfully, it will finally ask you to reboot your system. Confirm to let the system reboot (it will boot with an updated kernel).

Once up again, double-check your config file /etc/ngcp-config/config.yml (sections will be rearranged now and will contain more parameters) and your domain/subscriber/peer configuration and test the setup. You can find a backup of some important configuration files of your existing installation under /var/backup/ngcp-mr3.5.1-* (where * is a place holder for a timestamp) in case you need to roll back something at any time. A log file of the upgrade procedure is available at /var/backup/ngcp-mr3.5.1-*/upgrade.log.

	sip:provider CE mr3.5.1 requires at least 2GB of RAM available as the minimum requirements of the installation section, otherwise certain features won’t work and you will run into arbitrary issues.