How can I separate the IP phone system from computers for less than 50 users.

Where we are, business lines normally have 6 IP addresses assigned to the business. Check this.

We set up another modem on one of the other IP addresses and set the IP Phone system up on that. This prevents network traffic levels (volume of traffic) interfering with IP phones as well as the other way around.

Do you want your computer to be connected directly to an outlet or to the phone (daisy chain scenario)?

What model router behave you have? And are your switches managed? VLANs would be the best approach to this without having additional equipment. This also assumes you want daisy chaining.

Alternatively, you could create a second LAN subnet on your router, and have separate switches and wiring.

Based on what I see at clients with IP Phones, you probably want (need) a separate internal network for phones (separate from the computers)

What is typical is separating voice and lan traffic using vlans and using QOS to prioritize the VOIP traffic. You could use any number of products to do this. i.e. ubiquiti edgerouter X,  or one from the list provided @ https://www.networkstraining.com/best-hardware-firewalls-for-home-small-business/ 

The Ubiquiti products do not incur additional licensing costs  where a majority of the others do have additional licensing costs and some will brick your network if the license expires.

OK, so I have the following:
- PepLink Balance One router connected to 3 unmanaged switches. One of the switches connects to the UCM6208 that manages the phone system and yes, the phones are daisy chained, connected to a PC or laptop. Right now we have only one network, 192.168.0.x and running out of IP addresses, that's why I need a solution.

The big question is what are you willing to replace?

So I see here that your existing router supports VLANs, and also supports QoS. So you need to create at least one additional VLAN. But also, you're going to need to configure the phones and router ports properly. (This would be somewhat easier if you replaced the switches with managed units as you'd be able to configure individual switch ports)

I believe we start narrowing it down.
I'd like to achieve this without the addition of any hardware, possibly VLANs with QOS.
Is that possible with the existing hardware?
If yes, could someone guide me through the details, for I have no, or little experience with this.

I think you need to have an ordinary modem on your Internet line (you have 6 IP addresses business - correct?)

Then put your phones that.

This is to prevent one system (network traffic) overloading / conflicting with the other system (phones).

Where we see clients trying to save by having one system, phone quality usually suffers.

Sorry John, I don't understand what you're saying, could you be more specific.

Let my try to clarify.

Modem One on IP (1) 123.456.789.15   External IP for Network
Modem Two on IP (2) 123.456.789.16   External IP for Phones.

You need Ethernet wiring in the office for Phones but that should not be hard.

So, in other words you're telling me that separating the phone lines is not feasible with the existing setup/hardware.
For what we have now is internet coming is through AirLInk (no modem) in the building. The line goes directly to the router (WAN link) and from there with NAT we have one big network that includes the phone lines (that use static IPs), computers/laptops and WiFi. and that's 192.168.0.x. The thought was to create and 192.168.1.x for the phone lines to free up more IP addresses.
We currently have around 40 laptops/pc's, 45 phone extensions and between 10 and 20 mobile devices.
I don't want to spend any money if possible for the new setup, just improve the existing one.
Hope you have the big (existing) picture by now. If not, please ask specific questions.

The issue is more of keeping phones happy.  You can keep everything on one network. If it all works and everyone is happy - fine. Be prepared to separate the systems.  That is what happens to our clients

Sorry, again I am not understanding what you're trying to convey.
What do you mean by "Be prepared to separate the systems.  That is what happens to our clients " What exactly happens to your clients?
So far the system works as it is, but we need more IP addresses available.

What I mean is have Network (Server, Workstations, Printers and so on) separate from Phones.

I think that should be clearer to you now.

I would appreciate any other ideas, for this is not resolved yet. Thanks

You can wait and see and possibly seek some consulting expertise as this is new to you.

Making a simple network even bigger to add different functions is not something we do and have to fix up client systems who have done this. So I do not recommend what you are trying to do

Hi John, I understand your point and appreciate your expertise.

Your router supports QOS enable it https://www.peplink.com/company/peplink-enterprise-features/#qos it also supports port based VLAN put your phones on one VLAN and your pc's on another and maybe guest wireless on a 3rd

Are your phones/PCs on separate switches of your other devices?

If the answer is yes, then there might be a doable solution without replacing anything.
If the answer is no, then you're going to be better off replacing the switches with managed switches.

VLANs provide a lower cost approach to separating things, but introduces a level of complexity. John's separation suggestion is simpler (in terms of how things are segregated because it's literally physical), but costs considerably more because of the expense of hardware and cabling. Personally, I'd get managed switches and go the VLAN route, even if you need to bring in a consultant. Save the expense of wiring until a day you truly need to do so.

Masnrock, no the phones are not on separate switches, so you're telling me it's not possible to set up VLAN's without hardware changes?

To separate phones and network you need an Ethernet cable for phone and one for network in each office. So you will need hardware changes to accomplish list.  At the modem end, VLAN or separate Modem - your choice.

Attila, your best bet is getting managed switches. Here's the problem: If you created the VLANs on your router, every device still needs to know which VLAN to connect to. By default, a lot of people would've said VLAN1 for data. Which would then force you to find a way to have your PepLink tell the phones to connect to VLAN2 (using 2 for the sake of argument). Managed switches actually tend to provide some cleaner approaches than you have available now.

Forgot to mention that we are using DHCP reservations in the router, based on the MAC address. We use static IP addresses for the phones and desktops and laptops, but we still have a range for dynamic DHCP, that is limited, that's the reason for wanting VLAN, to free up IP's. Looks like it's not possible without some hardware changes.

Thank you John, masnrock and David Johnson for all your assistance.
I might revisit this one later.
-Attila