VoIP - Internet telephony

VoIP (Voice over IP) uses the Internet for transmitting calls and has been used by prime office since 2005. In contrast to con­ventional tele­phony which communi­cates via special analog or digital (ISDN) lines, VoIP only requires an Internet connec­tion from an ISP (Internet service provider). VoIP requires a standardi­zation of the proto­cols used so that all phones can communi­cate with one another. SIP/RTP have estab­lished them­selves as stan­dards here.

VoIP advantages

In addition to cost savings, VoIP offers several advantages:

  • wide range of devices
  • integration of IT (CTI)
  • mobility / home office
  • company networking

VoIP standards

The standardi­zation means that a wide range of phones are available, which has a positive effect on acqui­sition costs. Calls can be made on the PC via a softphone. The phone system can be operated on stan­dard hard­ware (e.g. HW appliance Px10) or in the cloud, which reduces opera­ting costs signi­ficantly.

VoIP risks

When using VoIP, you must take into considera­tion that an Internet outage will also affect phone communi­cations and that the techno­logy is more suscept­ible to cyber attacks. This means that sophisti­cated protection is required.

VoIP terminology

Session Initiation Protocol

SIP is the most important protocol when using VoIP. SIP is responsible for actions made on the phone, such as dialing the number, phone ringing or ending the call. RTP is used for call transmission, whereby both protocols are available in secure variants.

Asterisk

Asterisk is an open-source softphone system that has been installed millions of times around the world and enables systems with thousands of phone lines to be implemented. Asterisk is available as a stand-alone software solution or in connection with a HW appliance. prime office-phone is based on Asterisk and can be installed on the HW appliance Px10.

Quality of service

The Internet is used simultaneously by many other services in addition to telephony. Suitable measures must be taken to ensure that the phone connection has the necessary quality or priority, otherwise this can have a negative effect on call quality.

Microsoft Skype

Skype is the most widespread proprietary VoIP industry standard. Skype for Business is a completely different product (formerly Lynx) and requires complete integration into the Microsoft environment.

Skype, WhatsApp etc.

In addition to powerful open standards such as SIP or RTP, there are also companies who offer proprietary systems with the goal of setting industry standards. This usually leads to an increased dependency on a provider and significantly increases the price of the phone systems.

Typical closed industry standards include the following:

  • Cisco (MGCP)
  • Microsoft Skype
  • Various apps
    WhatsApp
    Facebook Messenger

Skype, WhatsApp etc.

In addition to powerful open standards such as SIP or RTP, there are also companies who offer proprietary systems with the goal of setting industry standards. This usually leads to an increased dependency on a provider and significantly increases the price of the phone systems.

Typical closed industry standards include the following:

  • Cisco (MGCP)
  • Microsoft Skype
  • Various apps
    WhatsApp
    Facebook Messenger