Welcome to the help center

In the help center you can find a FAQ section as well as comprehensive user guides for our software.


In case you have questions which requires personal assistance then you are more than welcome to contact our support team who will deal with your enquiry from Monday to Friday from 9 AM to 4 PM CET.

M2M stands for machine-to-machine communication. This involves data exchange between one or more machines at one end and users or machines on another end. The connection can take place in various ways, e.g. via mobile communications, DSL or analog connections.

SIM stands for Subscriber Identity Module. The SIM is available as a removable card or as an installed SIM chip. It stores the Service Subscriber Key (IMSI) and thus identifies the user of a mobile communication or data connection in a network.

GSM (Global System for Mobile Communication) is a standard for fully digital mobile communications networks which is mainly used for telephone calls, but also for circuit-switched and packet-switched data transmissions and short messages. It is the first standard of the so-called second generation (“2G”), the successor to first generation analog systems (in Germany: A network, B network and C network) and is the world’s most widely used mobile communication standard.

GPRS stands for General Packet Radio Service. This technology is used for mobile communication connections in GSM standard (Global System for Mobile) for internet and data communications. It is a billing system based on data packets in which only the actual amount of data is billed. This way it is possible to have a device online at all times without incurring additional costs.

EDGE (Enhanced Data rates for GSM Evolution) is a mobile communications standard of the second generation (2G) which allows for significantly higher data transmission rates (up to 220kbit/s) compared to what is possible with the first generation mobile communications standard (GPRS).

In third generation mobile telephony, mobile devices provide services with data rates up to 2 Mbps for stationary systems (with HSDPA, it can go up to 14.4 Mbps). Mobile systems can reach up to 384 kbps. 1G was the analog mobile telephony, while the 2G was digital, 3G uses a 5 MHz channel width as a carrier.

4G is the fourth generation mobile telephony, an umbrella of standards under development beyond 3G. Much of it is to get mobile systems to fuse together with other networks such as Wi-Fi and WiMAX.

UMTS (Universal Mobile Telecommunications System) is a third generation (3G) mobile communications standard which allows significantly higher data transmission rates (up to 84Mbit/s with HSPa+, otherwise maximum 384 kbit /s ) than with the mobile communications standard of the second generation (2G), the GSM standard (up to 220kbit/s for EDGE; otherwise maximum 55 kbit/s). 3G high-speed data transmission is particularly suitable for data-intensive applications

HSDPA/HSUPA (High Speed Downlink/Uplink Packet Access) is a data transmission standard and the further development of UMTS. This method enables data transmission rates in mobile communication networks similar to DSL rates.

Following the upgrade of the UMTS stations to HSPA, speeds up to 5.8 Mbit/s could be achieved for uplinks.

APN stands for Access Point Name. The network access point is required for GPRS/3G/HSDPA/HSUPA transmissions in order to establish a data connection. Usually the standard APNs of the network operators are configured in the mobile devices.

Every mobile communications service provider has Public APNs. These can be used by any customer. When a SIM card is activated for data connections, the APN is usually automatically activated.

Private APNs provide the user with direct access to his LAN and set numerous parameters, e.g., a dedicated IP address book to which individual devices can be assigned, or radius server parameters which make user authorization easier.
Data traffic is secure when using a private APN as it does not run through the public network.

Because the data stream in data connections is calculated for both directions (up and downlink), mobile communications network operators have highly developed firewalls in place to prevent mobile communications devices from being accessed through the Internet.

This means, without private APNs, the data connection must always be established from a mobile communications device. This prevents integration in networks.

A private APN is therefore an essential prerequisite for the availability of a device that is connected via mobile communications.

This is why DolphinM2M offers access via private APNs.

Block rounding: Generally, the costs for data transmission via mobile communications are calculated by actual data volume. However, often this data volume is calculated by a time limit according to the rate, or, if a GPRS connection is closed, the volume is rounded to a specific value (e.g. 100 kByte) (“Block rounding”).

This means that, for example, a block rounding of 100 kByte per hour could have the result that a constant GPRS connection is calculated as a data volume of 2400 kByte per day, even though only a small portion of this data volume was actually transferred.

Therefore, one should make sure to choose only small block rounding in a tariff or data tariff which offers either a high inclusive volume (e.g. from 5 MB per month) or a long rounding interval (e.g. every 24 hours).

An IP address is an address in a computer network, such as the internet, that is based on the Internet Protocol (IP). It is assigned to devices connected to the network and allows these devices to be addressed, and thus available.
The IP address can stand for an individual recipient or a group of recipients (multicast, broadcast). In reverse, one computer can have several IP addresses.
The IP address is used to transmit data from the sender to the recipient. Similar to a postal address on an envelope, data packages are provided with IP addresses that clearly identify the recipient.

With this address, the “post offices”, the routers, can decide in which direction the package needs to be transported. In contrast to postal addresses, IP addresses are not bound to a specific location.

The best known notation of today’s common IPv4 addresses consists of four numbers, which can have a value of 0 to 255 and are separated by a point, for example, From a technical viewpoint, an IP address is a 32 digit (IPv4) or 128 digit (iPv6) binary number.

A public IP address can be seen and reached by all internet users.

This means every user has access to the connected devices, like computers, web servers or webcams.

A private IP address is an address generated by a logical address space reserved by the Internet Standard Group for private use. Private IP addresses cannot be reached from the internet and are usually used in private networks. In order to reach a private IP address from the internet, one needs a router or similar that supports Network Address Translation (NAT).

In this case, the private IP address is hidden and only the portion of the data traffic that complies with the configured safety rules is transferred.

A fixed IP address is a static IP address. This address is usually assigned to a computer by the Internet provider to ensure that the user is permanently available at this address. In principle, it is like a telephone number for reaching a computer.

A fixed IP address is the condition for the integration of a device in the network.

A dynamic IP address is the opposite of a fixed IP address. When a device logs on to the internet or a network, it is assigned an IP address. When the connection is terminated, the device loses the IP address and the address can be assigned to a different device.

At the next log-in, the device receives a new IP address.

The advantage of a device being connected via a public IP address is that it can be addressed and reached via the internet at all times. This makes it possible to integrate devices, servers and systems into networks without requiring a VPN Tunnel (Virtual Private Network Tunnel).

This is a perfect solution when numerous users want to access one device. If the device is connected via mobile communications, a flat rate tariff is recommended because the owner of the data card only has limited control over the data transfer and data volumes are calculated for both for up and downloads in mobile communications.

The advantage of a device being connected via a private IP address is that it cannot easily be reached from the internet, before a VPN Tunnel (Virtual Private Network Tunnel) is established with the device.

This provides additional security for safety-critical applications and applications for which a small data option was selected.


An OpenVPN Tunnel is a program for the creation of a Virtual Private Network (VPN) via an encrypted SSL connection. The libraries of the OpenSSL program are used for encryption. Open VPN optionally uses UDP/IP for transport.

OpenVPN is free software and supports various operating systems such as Linux, Windows 2000/XP and others.

You require an OpenVPN Client when you want to use a private IP address with an OpenVPN Tunnel but do not have a router or similar hardware. You can establish an OpenVPN connection with a VPN Client that is installed on your computer.

You will receive access data and then only need your user name and a password.

A ping is a diagnostic tool with which one can test whether a specific host in an IP network can be reached and what response time it has. Ping sends an ICMP Echo Request Packet to the target address of the host being checked.

If the protocol is supported, the recipient must send a response according to protocol specifications: ICMP-Echo-Reoky. This program is usually run as a console command.

The home location register (HLR) is a central database that contains details of each mobile phone subscriber that is authorized to use the GSM core network.

There can be several logical, and physical, HLRs per public land mobile network (PLMN), though one international mobile subscriber identity (IMSI)/MSISDN pair can be associated with only one logical HLR (which can span several physical nodes) at a time. The HLRs store details of every SIM card issued by the mobile phone operator. Each SIM has a unique identifier called an IMSI which is the primary key to each HLR record.

The next important items of data associated with the SIM are the MSISDNs, which are the telephone numbers used by mobile phones to make and receive calls.
The primary MSISDN is the number used for making and receiving voice calls and SMS, but it is possible for a SIM to have other secondary MSISDNs associated with it for fax and data calls.

Each MSISDN is also a primary key to the HLR record. The HLR data is stored for as long as a subscriber remains with the mobile phone operator.

Examples of other data stored in the HLR against an IMSI record are: GSM services that the subscriber has requested or been given. GPRS settings to allow the subscriber to access packet services. Current location of subscriber (VLR and serving GPRS support node/SGSN). Call divert settings applicable for each associated MSISDN. The HLR is a system which directly receives and processes MAP transactions and messages from elements in the GSM network, for example, the location update messages received as mobile phones roam around.’

In wireless telecommunications, roaming is a general term that refers to the extending of connectivity service in a location that is different from the home location where the service was registered. Roaming ensures that the wireless device keeps connected to the network, without losing the connection. The term “roaming” originates from the GSM sphere; the term “roaming” can also be applied to the CDMA technology.

Traditional GSM Roaming is defined as the ability for a cellular device to automatically send and receive data, or access other services, including home data services, when travelling outside the geographical coverage area of the home network, by means of using a visited network.

This can be done by using a communication terminal or else just by using the subscriber identity in the visited network.

Roaming is technically supported by mobility management, authentication, authorization and billing procedures.

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