What is HUB?

This article describes what is a HUB in comparison with Switch.

A network HUB is a "dumb" multi-port repeater. A difference between HUB and Switch is illustrated on following diagrams.

Figure 1. HUB


On this diagram computers A and B communicate to each other (network packets are sent from A to B and in reverse direction).

When HUB receives a packet on one port, it sends out a copy of that packet to all other ports.

With a HUB computers C and D receive a copy of every packet, that is sent from A to B and back. They usually ignore such network packets because they know that these packets are destined to other computer.

Figure 2. Switch

In contrast to a HUB, a network switch is capable of inspecting data packets as they are received, determining the source and destination device of every packet. A network switch forwards packets between the specified sender and receiver ports only.

In our example, C and D will never receive a data which is not destined for them.

Switch is smarter than HUB and has better performance. In general, you should prefer using a Switch over HUB.

But HUB can be very useful, when you need to record voip calls. Its performance is enough for connecting a couple of voip phones to it (so, you should not worry about performance issue).

MiaRec uses HUB for call recording

MiaRec listens to network traffic which is sent to/from voip phone, decodes it and saves an audio on disk.

See below diagram for illustration.


Caution! Some of vendors mark their products as "HUB", but in fact these devices are "Switches".

Before you purchase a HUB, please, check if it is mentioned in the following list:


Note, if you have more than two phones, then you should consider using switches with port mirroring support (see What is port mirroring?). They are more expensive than HUBs, but these switches have superior performance and support voip call recording at the same time.


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