Pros and Cons of VoIP Phone (SIP) Adapter

Distinction of SIP telephone adapter from VoIP gateway

Phone VoIP adapter (or SIP adapter) is a real budget device that allows you to start access to IP telephony services.

You may have already read about significant savings on telephone calls for international, long distance, city and cellular communications using IP telephony. And, understanding the topic of economical technology of voice over Internet channels, found on the Internet a couple of options for technical “staffing” of analog telephone equipment that works in your office. Such options will be the use of additional devices that are connected to the telephone set, or if you have an office automatic telephone exchange – use of a proprietary extension card manufactured by the station’s manufacturer. However, not all PBXs have a mechanism for such an extension. If such a mechanism exists, the total cost of the card and the reprogramming of the office mini-PBX by the integrator company, which is necessary after its installation, makes significant financial investments. So instead of this upgrade, it’s better to just replace the existing analog station with IP-PBX, it will be significantly cheaper. It turns out that an expensive option with an expansion board, just disappears.

In the first “terminal” version, either VoIP telephone adapters are used, or VoIP gateways. These devices are often confused, calling the VoIP adapter a VoIP gateway or indicating that the VoIP adapter is different only in that it has a small number of telephone ports (usually up to 10), while several dozen phones can be connected to the VoIP gateway . But VoIP gateways can have 1-2 phone jacks and they do not call their VoIP-adapters.

A VoIP adapter is often referred to as a “SIP adapter”, since the main protocol for setting up a session in an IP telephony is SIP (Session Initiation Protocol). There are also such names of these devices – “ATA” (analog telephone adapter) and “FXS adapter” (the device houses an FXS port that is connected to the FXO port on a telephone or fax machine).
So what is the difference between a VoIP phone adapter and a VoIP gateway? What characteristics can make a better choice in favor of one of these devices?

Phone VoIP / SIP adapter: description

SIP adapter, connection

Pic 1. SIP adapter connection scheme

Most VoIP telephone adapter manufacturers refer them to the entry-level IP telephony equipment that is targeted at users in the SOHO area (Small Office / Home Office).

For example, to convert speech into packets of discrete data sent over IP networks, a VoIP adapter uses a processor with lower processing power than a VoIP gateway. And this, of course, affects the quality of the transformation and reproduction of the voice.
But if consumers are ready for such troubles, considering that the price factor is the determining factor for choosing a device, then the reliability and stability of its operation (again, determined by the characteristics of the element base), perhaps, will make consumers of IP-telephony equipment think.

Some vendors of VoIP / SIP adapters directly point out that these devices are manufactured for consumers who are not very important in reliability of communication. And on Internet forums, users of VoIP / SIP adapters evaluate their reliability and stability as “bad” or “close to satisfactory.”

Alternative to VoIP telephone or SIP adapter

The technical functions of VoIP gateways and VoIP telephone adapters are almost identical, on which marketers play. In these devices there are: automatic assignment of IP-addresses, there is the possibility of updating the software over the Internet, protection against unauthorized access (password connection), the implementation of dynamic network monitoring for cleaning from third-party interference and routing, as well as a small list and other important functions, necessary for the “entry” of an analog phone into an IP-telephony network.

SIP-adapter, two FXS-ports, connection of two phones

Pic 2. SIP adapter has two FXS ports for connecting two analog phones

However, VoIP adapters do not provide the levels of reliability, stability and quality of communication necessary for many users and therefore they can not compete with VoIP gateways, whose technical solutions are based on the use of high-performance processors and other electronic components of a higher class than in VoIP- adapters.

Phone VoIP / SIP adapter: conclusion

Any small enterprise increases with time, and with the increase in the number of employees it will be necessary to increase the subscriber base. At the same time, if VoIP VoIP adapters are installed in the company, it will be necessary to purchase these devices to expand the number of IP-telephony users. Therefore, even proceeding from this premise, from the very beginning of business activity it is necessary to purchase a VoIP-gateway with a “reserve” of ports, to which it will be possible to connect new subscribers.

Arguments in favor of the choice of VoIP gateways, which were mentioned above, are higher quality of voice, reliability and communication stability than SIP adapters.
In addition, most models VoIP Gateways have the capabilities of administration, bandwidth management and network security, as well as setting priorities, accounting and analysis of various types of traffic.
Thus, in spite of the fact that VoIP / SIP adapters are actively offered today as a budget start to start using IP-telephony services, you will be able to guarantee a successful start only with more reliable and high-quality IP-equipment, such as VoIP gateways.