Central Site Gateway

  • 1.000 VPN tunnels
  • IPMI interface
  • VRRP for maximum availability
  • Redundant power supply unit
  • Dual-core CPU
  • 4GB RAM
  • 120 GB SSD
  • 19" 1U housing

Functions and features

The VK4000 is a VPN concentrator (Central Site Gateway) with a capacity of up to 1,000 simultaneous VPN tunnel connections. This means that up to 1,000 branch offices can be securely and authentically connected to the host environment.

The VK4000 is equipped with redundant power supply units as standard, which together with VRRP (Virtual Router Redundancy Protocol) guarantees a high level of reliability. Intelligent security management and the implementation of IPsec, OpenVPN and WireGuard guarantee a secure network connection for the host systems.

The VK4000 comes in a 19" design and is intended for convenient installation in a server rack in conjunction with a rack mount system.

All features in detail

  • Modular software structure
    The modular software structure offers the option of integrating customised/custom-developed software.
  • DHCP (Dynamic Host Configuration Protocol)
    A communication protocol that enables clients to retrieve and servers to assign the network configuration (client/relay/server)
  • Protocols
  • DNS (Domain Name System)
    It manages the name space in networks, e.g. for converting domain names into IP addresses (client/relay/server).
  • Dynamic DNS
    Dynamic DNS: It is used to dynamically update the IP address of a computer so that it can always be reached under the same name.
  • NTP (Network Time Protocol)
     Standard for time synchronisation via networks (client/server)
  • Routing
    Static routing (IPv4 forwarding)
    Static routing (IPv6 forwarding)
    Policy-based routing (PBR)
  • NAT (Network Address Translation)
    Source and destination NAT/NAPT and masquerading
  • QoS (Quality of Service)
    For prioritising data packets to meet the quality standard, especially for time-critical transmissions/applications
  • Real-time statistics and log function
  • Syslog client
  • TPM (Trusted Platform Module)
    The TPM chip is comparable to a permanently installed smart card. The TPM protects cryptographic keys; these can be generated, used and securely stored within the TPM. It offers protection against software and hardware attacks (physical manipulation results in the destruction of the stored keys). In addition, the integrated random number generator (RNG) provides secure number sequences as the basis for securely encrypted communication.
  • Firewall
    Zone-based stateful inspection firewall (IPv4/IPv6) with packet filter and demilitarised zone (DMZ);
    Bridging firewall
  • OpenVPN
    Free software based on OpenSSL for setting up a secure VPN via an encrypted connection. Both routed and bridged tunnels (client/server) are supported.
  • IPSec
    Internet Protocol Security: for secure VPN communication via potentially insecure
  • L2TP (Layer 2 Tunneling Protocol), passthrough
    Tunnelling protocol for transmitting the data link layer (Layer 2) of the OSI model between two networks
  • WireGuard
    WireGuard uses the latest, particularly powerful cryptographic algorithms, e.g. the Noise Protocol Framework, Curve25519, ChaCha20, Poly1305, BLAKE2, SipHash24 or HKDF. WireGuard gets a further performance boost from the fact that the software is executed on the server side as a Linux kernel module. WireGuard uses only public keys for identification and encryption and can therefore dispense with a certificate infrastructure.
  • Hash algorithms
    MD5, SHA1, SHA2 256/512
  • Diffie Hellman Groups
    Schlüsselaustausch zum Sichern: 1, 2, 5, 14, 15, 16, 17, 18
    Modulo Prime Groups with Prime Order Subgroup: 22, 23, 24
    NIST Elliptic Curve Groups: 25, 26, 19, 20, 21
    Brainpool Elliptic Curve Groups: 27, 28, 29, 30
  • Encryption algorithms
    AES 128/192/256, Blowfish, Twofish 128/256, Serpent 128/256
  • Number of VPN tunnels
    The number of configurable VPN tunnels is not limited by the software. Depending on the application, up to
    - 30 VPN tunnels (VR2020 series),
    - 400 VPN tunnels (G3000 & G4000 series) and
    - 5000 VPN tunnels (G5000 series) are possible.
  • MultiWAN manager with complex backup options
    - Multihomed and multi-level backup target strategies
    - Optimisation of switchover times
    - Prevention of unnecessary switching
    - Optimisation of switchback
    - Prevention of switching instabilities (fluttering)
    - Mobile telephony: Provider switching with MultiSIM
    - Dynamic connection parameters (default route, policy-based routes, etc.)
    - Configurable connection check (ping, LCP echo, etc.)
  • VRRP (Virtual Router Redundancy Protocol)
    - With support for Multi group VRRP
  • Management/configuration
    Via the network using Command Line (SSH) and HTTPS as well as via Command Line (SSH) using the console port
  • Remote configuration/maintenance
    If required, remote configuration/maintenance can be carried out using the TR-069 standard. Configuration via TDT C.O.R.E. is also possible.
  • Firmware update
    Firmware updates can be realised via SSH, HTTPS and (TR-069).
  • SNMP (Simple Network Management Protocol)
    SNMP is a network protocol that was developed to monitor and control network elements from a central station.
  • Checkmk agent
    For connection to the Checkmk network management system
  • Processor
    Powerful dual-core processor
  • Memory
  • Hard disc
    120GB SSD (SolidStateDisk)
  • Ethernet-Ports
    4 Ports (10/100/1000 Mbit/s)
  • Expansion slots
  • USB Ports
    2x USB 2.0, 2x USB 3.2 Gen1
  • Other connections
    1x VGA, 1x COM-Port
  • TPM 2.0 (Trusted Platform Module)
    For secure storage of keys and certificates
  • Real-time clock (RTC)
    CMOS hardware clock
  • not available
  • not available
  • not available
  • Robust metal housing
    19″ 1U
  • Dimensions
    43x437x503 (HxWxD in mm)
  • Weight
    approx. 15 kg
  • Operating temperature
    0°C to +50°C
  • Air humidity
    40% (non-condensing)
  • Rack mounting rails
    Included, 65 - 84cm (toolless)
  • Redundant power supply
    2x 400 Watt redundant hot swap power supply (80plus Platinum, > 94%)
  • Average power consumption
    approx. 112W

VK4000, 2x power cable, patch cable, lockable front panel, extendable mounting rails 65 - 84cm (toolless)

Gateways model overview

ProductModelDSLMobile networkWLANWANSFP-PortSerialEthernetVPN-Tunnel
VK5000see Ethernetoptional4xup to 5000
VK5051see Ethernetoptional4xup to 5000
G4050see Ethernet3xup to 400
G4051siehe Ethernet3xup to 400
G4052see Ethernet5x (3+2)up to 400
G3000see Ethernet3xup to 400
G3000-Wsee Ethernet3xup to 400
G3000-L  (4G)see Ethernet3xup to 400
G3000-5G  (5G)see Ethernet3xup to 400
G3000-LW  (4G)see Ethernet3xup to 400


For the moment the data-files are available in German language only.