From HiPBX Wiki

Contents 1 Server(s) 2 Network 3 Phones 3.1 IP Phones 3.2 Regular/Analog Phones 3.3 Softphones 3.4 PSTN Connectivity

Server(s)

The server is any computer on which you've installed Linux, FreePBX, Asterisk, and any other programs needed to run your phone system. All of these are installed as part of HiPBX, or on one machine when you're using a standalone build (eg, FreePBX Distro, Elastix, PIAF, etc).

These machines should always be dedicated servers, that do nothing than act as your phone system. If you're not requiring physical connectivity to the PSTN (eg, with DAHDI), you can quite happily run these as VMs using virtualization - Hypervisors such as Proxmox and VMWare are well tested.

Network

A VOIP PBX and its phones are all connected together using a standard ethernet computer network. To use VoIP reliably, you should be using a 100MBit Ethernet network.

Phones

Obviously without phones, a PBX is not going to be able to do a whole lot. You can buy actual telephones that connect to a computer network (IP Phones), or you can buy adaptors that allow you to connect regular phones to your computer network (ATA Adaptors), or you can even use software running on your computer or other portable device to make it act as a phone (softphone).

HiPBX is using the Cisco SPA5xx series phones as their officially supported device.

IP Phones

IP phones are by far the best way to go when setting up a FreePBX-based system. They typically offer programmable buttons that make using various features easy (compared to dialing star codes, like *57). Most have multiple lines, which allow you to very easily manage more than one call to your extension. There are many manufacturers that make IP phones, and many many models that range in price from $80 up to $500. Within a single deployment, it's good to standardize on one line of products simply for end user ease-of-use, but you can mix and match all you like.

Regular/Analog Phones

Analog phones are the standard phones that plug into a normal phone line and use. The primary way to use these with a HiPBX system is with Astribanks from Xorcom. These are the only devices that allow two servers to connect to one port, allowing failover. In a single-server FreePBX network - non-clustered - there are PCI/PCIe cards that can connect to a FreePBX system. Alternatively, using an ATA (analog telephone adapter) provides you with a reliable, clusterable, connection, as it plugs directly into the network jack. Unfortunately there aren't any high capacity devices to compete with the Astribanks, so they're only useful for a small number of connections.

Softphones

This is software that you install on to your PC, that talks back to Asterisk, and appears just like any other IP phone. You need a microphone and speakers of some sort (headset, usb device) to actually use it to place calls. There are many different softphones available for most platforms. They are useful for testing and connectivity while on the road (eg, on a laptop), but most people do not use them as a primary device because you're relying on a PC working, being turned on, user logged in, etc.

PSTN Connectivity

Like phones, there are many ways to interface to the rest of the world, i.e. the Public Switched Telephone Network ("PSTN"). A PSTN interface is a way to connect regular telephone lines to your PBX.

• POTS

Plain old telephone service. This is the type you have at home or in a small office, it is an analog service and is normally provided to you via an RJ11 jack. This supports one call (one channel) at a time, and is the most basic service. Generally each POTS line gets its own public phone number.

• PRI (E1/T1)

Primary Rate Interface. This is a digital line that carries 30 64kbps voice (B) channels (24 in the US, where it's referred to as a 'T1'), and one 64kbps signaling (D) channel used for call setup, caller id, etc. You can have any number of incoming DIDs ("direct inward dial" - a term that refers to a public phone number) on a PRI. It is the best interface to use when dealing with several lines. Most PRI's come in groups of 10 lines, with 100 DID's. It is important to differentiate between DIDs and simultaneous calls. You can think of a DID as a seat number on an airplane, but the airplane is only able to carry a small number of passengers. So whilst there may be 100 seats, only 10 of those seats can be in use at the one time.

• ISDN BRI

Basic Rate Interface. This is a digital line carrying two 64kbps voice (B) channels and one 16kbps signaling (D) channel. It is not widely used with Asterisk systems.

• VoIP Provider

Using a Voice over IP provider is another way to get connected to the PSTN. Most businesses do NOT use VoIP as their primary connection because it's unreliable compared to direct PSTN connections. It's susceptible to other internet traffic hogging bandwidth, and there are more points of failure (your ISP, your provider, your provider's ISP, and everyone else in between).