CWMP ACS TR-69 Provisioning DHCP Option

CWMP ACS TR-69 Provisioning

Technical Report 069 (TR-069) is a technical specification of the Broadband Forum that defines an application layer protocol for remote management of customer-premises equipment (CPE) connected to an Internet Protocol (IP) network. TR-069 uses the CPE WAN Management Protocol (CWMP) which provides support functions for auto-configuration, software or firmware image management, software module management, status and performance managements, and diagnostics..

The TR-069 protocol allows DHCP servers to send one or more vendor-specific parameters to the client router. A CWMP configuration requires the following parameters for the URL to the auto-configuration server (ACS) for provisioning via ISC-DHCPD:

subnet netmask
        option routers;
        append dhcp-parameter-request-list 43;
        option vendor-encapsulated-options 01:12:68:74:74:70:3a:2f:2f:61:63:73:2e:69:73:70:2e:6f:72:67;

Example ACS URL

The option vendor-encapsulated-options must be specified as an encoded sequence of identical syntax with code, length and value field to the DHCP option.

The code for this option is 43 and its minimum length is 1.
Code Len Vendor-specific information
|  43 |  n |  i1 |  i2 | ...

When encapsulated vendor-specific extensions are used, the
information bytes 1-n have the following format:

Code Len Data item Code Len Data item Code
|  T1 |  n |  d1 |  d2 | ... |  T2 |  n |  D1 |  D2 | ... | ... |

Section: IETF rfc2132 – DHCP Options and BOOTP Vendor Extensions


For the conversion is the following bash script, which can run as follows ./url2hex

if [[ -z $1 ]]; then
  echo "Argument missing! Use: url2hex url"
  exit 1
echo ""
echo -e "[[[ URL2HEX Converter ]]]\nTR-069 CWMP request ACS URL provisioning on ISC-DHCPD option vendor-encapsulated-options"
echo "URL:$1"
wcount=`echo $1 | wc -m`
tcount=`echo ${wcount}-1 | bc`
length=`printf '%x\n' ${tcount}`
hexurl=`echo -n $1 | xxd -ps | sed 's/[[:xdigit:]]\{2\}/\:&/g'`
echo -e "URL-length:${tcount} HEX:${length}\n\nvalues for CWMP provisioning in dhcpd.conf:\n"
echo "append dhcp-parameter-request-list 43;"
echo "option vendor-encapsulated-options 01:${length}${hexurl};"

Save the code lines to a file url2hex and make them executable.

$ chmod u+x url2hex

The string input is converted to HEX, after which the values are hung together, starting from 0x01 for the value of the CWMP option to ACS URL.

The output can then look like this:

[[[ URL2HEX Converter ]]]
TR-069 CWMP request ACS URL provisioning on ISC-DHCPD option vendor-encapsulated-options
URL-length:19 HEX:13

values for CWMP provisioning in dhcpd.conf:

append dhcp-parameter-request-list 43;
option vendor-encapsulated-options 01:13:68:74:74:70:73:3a:2f:2f:61:63:73:2e:69:73:70:2e:6f:72:67;

The last two rows can be added in dhcpd.conf.


TR-069 Boadband Forum, art. “3.1 ACS Discovery”
RFC2132 – DHCP Options and BOOTP Vendor Extensions, art. “8.4. Vendor Specific Information”.

How to Install Nextcloud on Synology

Nextcloud installation and deployment on Synology DiskStation.

Synology Diskstation comes with many packages pre-installed, more additional packages can be installed from the DSM Package Manager. If you want to have Nextcloud on the Synology NAS, you still have to proceed manually. Here it is described how to deploy Nextcloud on a Disksation in a few steps. This should be possible with any Synology DS or RS series.

How it’s done

CalDAV Integration
Protection and Configuration

To prepare, some service packages must be installed as usual from the DSM Package Center.

Synology DSM Package Center


The php 5.6 and PHP 7.0, Apache 2.4, phpMyAdmin, MariaDB and Web Station packages are installed.

The terminal access to Synology DS is required, how to activate the SSH daemon, is in the post here.

In order to be able to log in to diskstation as root with PuTTY, you need the following command to activate root access. Or you can run sudo in each case.

$ sudo synouser -setpw root password

Download from Nextcloud and unzip the ZIP archive with subsequent owner and rights assignment. The Document_Root here is /volume1/web/nextcloud.

$ cd /volume1/web
$ curl -O
7z x
$ chown -R http:http nextcloud
$ chmod -R 0777 nextcloud

A MySQL root password must be assigned.

$ mysql -u root -ppassword
ALTER USER 'root'@'localhost' IDENTIFIED BY 'newpassword';

The MySQL-root password can of course also be changed from the DSM.

Reset MariaDB Password

Now the DSM Web Station is opened to create the web server configuration and a virtual host.

Synology DSM Web Station

Web Station General Settings

Synology Web Station General Settings

Web Station PHP settings. The PHP open_basedir field must be none.

Synology DSM Web Station PHP Settings

Web Station Create Virtual Host.


Now the URL can be opened in the Bowser https://ip_adresse_od_hostname/nextcloud

Create a Nextcloud administrator account

The administrator account can be any name, it is not related to the Synology users. MySQL/MariaDB is selected, the MySQL-root password is the previously assigned password.

After about 2 min. the installation is completed and the intro page appears.

If our own Nextcloud is to be accessible from the Internet, a static NAT port forwarding to the internal Synology Diskstation on the firewall must be made. Furthermore, the file config.php located under nextcloud/config must be adapted. In the array, another line is added with our FQDN, which was previously entered in the DNS zone

$CONFIG = array (
'instanceid' => 'lckfp7we8ddv',
'passwordsalt' => '&9p40M+uM3cZBPrWKwV)EEwSoPtvJ',
'secret' => 'klkajd8&DF3A.$=o?pqHAR4@+LXD6n-LaQhbfgt&/H',
'trusted_domains' =>
array (
0 => '',
1 => '',
'datadirectory' => '/volume1/web/nextcloud/data',
'overwrite.cli.url' => '',
'dbtype' => 'mysql',
'version' => '',
'dbname' => 'nextcloud',
'dbhost' => 'localhost',
'dbport' => '',
'dbtableprefix' => 'oc_',
'dbuser' => 'oc_admin',
'dbpassword' => 'LeG2iRzcvc1XT8mpoGntS18GeYXGi3',
'installed' => true,
'mail_smtpmode' => 'smtp',
'mail_smtpauthtype' => 'LOGIN',
'mail_from_address' => 'noreply',
'mail_domain' => '',
'mail_smtphost' => '',
'mail_smtpport' => '25',
'maintenance' => false,

CalDAV Integration

With CalDAV Synchronizer for Outlook it is possible to easily synchronize the Outlook calendar, the address book and the tasks, so that every desktop and mobile client is integrated via the private Nextcloud.

The free Outlook plugin from the University of Applied Sciences Technikum Wien, which synchronizes between Outlook and CalDAV Server, supports the Outlook versions 2019, 2016, 2013, 2010 and 2007. The download is available on Github and at Sourceforge.

Protection and configuration

To secure synology DS accessible from the Internet, access rights should be restricted with the following chmod command:

$ cd /volume1/web
$ chmod -R o-w nextcloud

Furthermore, HTTPS should be used, Nextcloud recommends making the following setting on the Apache web server configuration:

$ vi /usr/local/etc/apache24/sites-enabled/httpd-vhost.conf

This redirects the call to the web page from http to https (SSL), in the Virtual Host Configuration under Add ServerName:

<VirtualHost *:80 *:443>
   Redirect permanent /

In order for an HTTP connection to be rejected when trying to establish an HTTP connection, the module can be added mod_headers.c.

<VirtualHost *:80 *:443>
    ServerName nextcloud
    SetEnv HOST nextcloud
    DocumentRoot "/volume1/web/nextcloud"
    <IfModule dir_module>
        DirectoryIndex  index.html index.htm index.cgi index.php index.php5
    <IfModule mod_headers.c>
        Header always set Strict-Transport-Security "max-age=15552000; includeSubDomains"
    <Directory "/volume1/web/nextcloud">
        Options MultiViews FollowSymLinks ExecCGI
        AllowOverride All
        <IfModule authz_core_module>
            Require all granted

The search engine crawlers should be informed that our Nextcloud website should not be indexed. The text file robots.txt is located in the document root, in the directory /volume1/web/nextcloud.

cat << EOF > robots.txt
User-agent: *
Disallow: /

Use Copy Paste to create the robots.txt text file.

For performance optimization, the PHP opcache can be configured. Add the values to the PHP configuration user-settungs.ini as follows:

cat << EOF >> /volume1/@appstore/PHP5.6/usr/local/etc/php56/conf.d/user-settings.ini

By copy pasting in the user-settings.ini file.

Now the Synology DS only needs to be restarted for the configuration to be active.


With Apache 2.4 and PHP 7, Nextcloud runs a lot more performantly, so it is recommended to run the Web Station for the Virtual Host of Nextcloud with the current Web Services.

Synology Virtual Host for Nextcloud