IP PBX and VoIP Gateways: What’s the Difference?
According to networking professional Carrie Higbie, IP PBX and VoIP gateways differ when it comes to how they perform voice transmission data functions.
Higbie states that voice conversations can be transmitted either by digital or analog means. The transmissions can then be compressed into data packets that are transferred via the data network (VoIP). The conversation is deconstructed into smaller ones, so that the voice packets can be placed into a data packet.
The beginning of packetization is the main aspect to consider, here. With regards to IP PBX, the telephones and telephone switches are native IP, which means that, at the source, the conversation is condensed into voice packets and subsequently broadcasted as a native IP packet that is reconstructed on the receiving end. Non-IP PBX and older systems anticipate conversations to be broadcast over the Plain Old Telephone Service (POTS), or otherwise. On the other hand, IP PBXs are able to convert POTS network compatible packets, like analog fax, as required.
A VoIP gateway deconstructs conversations and compresses the IP packets at the edge of the network so that it can be transmitted across the IP network. The old, analog voice network differs because it believes that it is going to broadcast across the POTS network, while the VoIP gateway conversation is packetized into VoIP digital packets. The benefit of having a gateway is that it enables businesses to be able to upgrade to VoIP, or function in a diversified environment where the gateway is the “translator”.
Costs can be high when it comes to upgrading wholesale PBX, especially if the cable pairing for data transmission is not sufficient. Two or more wires may be necessary for some VoIP phones, such as those that are Power over Ethernet-enabled. If the old voice connection were lacking while the data connection at a desk is being used, then it would be possible to employ a switch-enabled telephone or upgrade to the latest standards-based four-pair cabling system.
Whether or not a VoIP gateway is the only option for areas that want VoIP depends on the extent to which the PBX switch is denigrated. If the PBX switch is completely depreciated then a VoIP gateway might be the only route for locations that desire VoIP.
Take as an example, a business that has spaces in three different cities, where the main location (City A) has standard PBX, and the newer, smaller locations (Cities B and C) communicate using VoIP. A VoIP gateway would exist on the cusp of City A and, at the same time, interpret the packets between Cities B and C. The communications between City B and C would not require a gateway, as they would converse with one another natively across their VoIP switches.