Disadvantages of IP telephony

Here, the shortcomings of IP telephony are compared with the conventional (analog) telephone. In this case, it is not only about asterisk, but about any IP telephony systems: both paid and free. Advantages of IP telephony, see here.

  • The expensive equipment (usually not the PBX itself, although some digital / software PBXs are very, very expensive).
  • For IP PBX you need a computer (it can be part of the PBX, but it’s still a computer), which means that there may be disk failures, and other components.
  • As a rule, the complexity (and correspondingly, high cost) of the initial setting.
  • In any case (and if the PBX is connected to the Internet, it increases many times) there is a risk of hacking the PBX, in this case, the amount of payment for telephony can be tens and hundreds of thousands of dollars (and this is no exaggeration).
  • As a rule, the complexity of supporting telephony (adding subscribers, changing/adding telephony operators, etc.), which requires the availability of a qualified specialist (any telephone operator/computer technician will not be suitable here).
  • With the individual configuration of the configuration (which is the rule), PBX programming is required, as a result (like any program) there may be malfunctions, errors, etc., which may cause “wrong” calls (and other problems), which at best The case creates confusion, and at worst can spoil the company image and/or lead to additional expenses for telephony.
  • The presence of many features in a digital PBX, many of which are included by default, is not always good. For example, PBX can record conversations, as well as listen to any telephone conversations in real time (and much more). Employees who know how to use these options, in theory, can use them (unless you provide additional protection or disable such PBX capabilities).
  • For telephone communication, a local computer network (and the Internet, when connected to SIP providers) is used, so connection breaks, poor sound quality, etc. are possible. With a high network load and/or a slow/busy Internet connection.
  • As with analog telephony, glitches of VoIP equipment (both IP-phones, VoIP / gsm gateways, adapters, etc.) are possible, but since VoIP equipment is more complicated, the risk of its breakage is higher.
  • Faxes. Although some [managers] are trying to assure that faxes are transmitted better over IP telephony than analog telephony, this is not the case. In an ideal situation, IP faxes are transmitted as well as an analog. Any optimization/compression of telephone traffic leads to a deterioration or even complete impossibility of sending faxes.
  • Since a computer network is used for telephone communication, it is possible (as well as intercepting passwords) to overhear telephone conversations (regardless of the PBX settings), “peep” at which numbers call subscribers, etc.
  • Finally, in fact, IP telephony is not always the cheapest solution. In some cases (for example, for mobile calls within Russia within the same operator’s network), the call price may be lower than via IP telephony (the cost of the call can be even zero, depending on the tariff and operator). So in each case, it is necessary to make an individual decision about the use of IP telephony.