A. Requirements

Internet connection requirements

  • The bandwidth requirements at the location are:
    – audio: 100 kbit/s per simultaneous call
    – video: up to 2 Mbit/s per direction (send/receive)
  • The internet connection must also have a continuous latency of less than 100 ms (measured from DE-CIX to device) and a packet loss well below 1 %.
  • When using a firewall, the customer must configure and change it for the VoIP data stream to allow communication between the phones and the DFN platform.

HD video (1080p) usually requires only 1 Mbit/s per direction.

Customer network requirements

  • Professionally installed local network infrastructure based on at a minimum full duplex 100 Mbit/s switches and of type CAT5e or better.
  • Even during peak times, the network must not run at full capacity and must have adequate capacity available for the anticipated voice traffic. Separating and prioritizing the telephony data, e.g. via VLAN, is an ideal type of option.
  • For high volume data exchange over the local network, using separate switches for IP phones and desktop PCs is recommended.
  • The customer must run a DHCP server which assigns IP phones a valid IP configuration including internet gateway designated for voice traffic. This DHCP server may not use Option 66 (BOOTP server).

E-mail infrastructure

If the customer would like to have inbound faxes or voicemail messages sent, the customer must have a functional email infrastructure (server and clients) to sent voicemails and faxes to the users.