Voice over IP

Audio via Inter­net
Arbeitsplatz Agent

Voice over IP, or VoIP, describes the trans­mis­sion of voice data via the Inter­net instead of using clas­sic tele­phone net­works (PSTN or ISDN). The Inter­net pro­to­col used for this pur­pose, IP for short (Inter­net Pro­to­col), was ini­tially designed only for switch­ing data pack­ets in com­puter net­works, but was then adapted to the data packet-​based trans­mis­sion of voice infor­ma­tion. It is pos­si­ble to com­mu­ni­cate via VoIP using a com­puter, tablet or smart­phone with Inter­net access.

Rev­o­lu­tion of com­mu­ni­ca­tion

Bril­liance meets usabil­ity

Voice over IP is voice com­mu­ni­ca­tion via the Inter­net Pro­to­col and is also described as IP tele­phony or Inter­net tele­phony. IP con­nec­tions are con­nected to the broad­band and thus allow telecom­mu­ni­ca­tion via the Inter­net con­nec­tion. In doing so, IP tele­phony allows data and tele­phone calls to be made over the same net­work. Using IP tele­phony requires a fast and sta­ble broad­band Inter­net con­nec­tion for good voice qual­ity. With IP tele­phony, the tele­phones are con­nected into the DSL router or a VoIP-​capable cable modem.

For tech­ni­cal rea­sons, the voice is trans­mit­ted over the Inter­net in the form of data pack­ets.

Inter­net tele­phony can be divided into three basic processes: Con­nec­tion setup, call trans­fer, con­nec­tion ter­mi­na­tion. The “Ses­sion Ini­ti­a­tion Pro­to­col” (SIP) is used to estab­lish and ter­mi­nate con­nec­tions, which enables VoIP com­po­nents to be inte­grated across man­u­fac­tur­ers. In SIP-​based sys­tems, each sub­scriber has its own SIP address. Indi­vid­ual dig­i­tal data pack­ets are trans­mit­ted for call trans­fer, for which the acoustic sig­nals recorded in ana­log form by a micro­phone must be con­verted into ana­log elec­tri­cal sig­nals.

These are then dig­i­tized, divided into numer­ous pack­ets and sent over a pub­lic or pri­vate net­work.


What is the use

  • Com­mu­ni­cate and col­lab­o­rate more effi­ciently thanks to the vir­tual PBX for sta­tion­ary and mobile IP phones, which offers fea­tures such as hold and a three-​party call or even fil­ter lists and inter­ac­tive voice response
  • Location-​independence thanks to acces­si­bil­ity from any Inter­net access point, even on the road, or even with smart­phones via an app, even at home and abroad
  • Cost reduc­tion thanks to the low con­nec­tion charges and low main­te­nance costs
  • Easy con­fig­u­ra­tion thanks to setup already done by the ser­vice provider via auto­pro­vi­sion­ing or inde­pen­dently by the cus­tomer after deliv­ery on site
  • High voice qual­ity thanks to dig­i­tal tele­phony, or even HD tele­phony with a much bet­ter trans­mis­sion qual­ity

Our part­ner solu­tions

Strong together
Microsoft Teams

Microsoft Teams

As a true all-​rounder, Microsoft Teams is both a cen­tral point of con­tact for vir­tual team­work and an inno­v­a­tive com­mu­ni­ca­tion plat­form.



The VoIP tele­phone sys­tem from inno­va­phone ful­fils all cri­te­ria of a mod­ern com­mu­ni­ca­tion solu­tion with its UC client myAPPS.



Poly sup­plies, among other things, mod­ern tele­phone ter­mi­nals, head­sets and con­fer­ence solu­tions — all with crys­tal clear voice qual­ity.



Avaya offers solu­tions in the areas of IP tele­phony, uni­fied com­mu­ni­ca­tions and call cen­ters.



audiocodes is one of the most impor­tant man­u­fac­tur­ers of audio gate­ways and ses­sion bor­der con­trollers in the field of VoIP.

Our suc­cess sto­ries

Here in action


Thanks to a smooth migra­tion process to mod­ern IP tech­nol­ogy at Ross­mann head­quar­ters and in the “old build­ing”, 700 employ­ees were able to work with­out down­time and now also han­dle day-​to-​day busi­ness inde­pen­dently.

Dis­cover more


With a smooth and suc­cess­ful mod­ern­iza­tion of the com­mu­ni­ca­tion infra­struc­ture, KALO’s billing experts as well as cus­tomer ser­vice can now enjoy more flex­i­bil­ity in their daily work.

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IPD Knowl­edge

In a nut­shell

You don’t under­stand a term or would like to get more infor­ma­tion about it to be on the safe side? We will be happy to help you! In our wide-​ranging glos­sary, all tech­ni­cal terms relat­ing to the topic of infor­ma­tion tech­nol­ogy are explained in a holis­tic man­ner, so that you always have a full overview. Dis­cover now!