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Expand Network for VOIP question

Posted: 2019/12/31 17:48:45
by northpoint
Hello Everyone,

I have been given the task of upgrading our network to handle cloud VOIP at a small company. The company has 10 workstations and a small CentOS7 server that currently handles routing/firewalling/samba for the workstations. My problem is I have never really had to setup VOIP before and have been studying it quite a bit. I just have some general questions on the subject.

The current layout for their network is pretty basic:

Modem (1 port only) -----> Server ------> Dumb Switch -----------> Workstations(11 total)

I realize that there has to be QOS for the phones sitting at each desk. There will be 14 phones in all. I will want to do POE for the phones so I will probably be adding or replacing the current switch with a smart switch.

In handling routing of the VOIP and QOS should I just let the new smart switch determine QOS and just forward everything thru the server. Is this a good practice to do? On this point I am assuming that I can have a smart switch that can configure the ports as POE or NOT POE? Or perhaps they automatically determine this? Im not sure as I have not worked with much else but dumb switches really.

I would appreciate anyone taking the time to respond. Im posting it here because its kinda a network question and involves CENTOS on the server.

Happy New Year Everyone,

Thank you,


Re: Expand Network for VOIP question

Posted: 2020/01/02 08:39:56
by KernelOops
PoE is automatic, once something PoE-enabled is plugged in, it will negotiate with the switch and power on. No need to do anything.

There is no special setup for voip, its just another TCP or UDP thing like everything else. Each phone will receive an address from your DHCP and will try to auto-configure itself (provisioning). If you setup your DHCP right, the phones will download their configuration (via tftp or https) and start working immediately. If you haven't prepared provisioning, then you'll need to configure them manually one by one, by visiting their web interface.

Do you have a PBX running in your network? or does your voip provider offer you a PBX service? One example of a complete PBX is FreePBX and their distro is based on CentOS.

Thats about it really, quite easy to setup the whole thing in a few hours.

Re: Expand Network for VOIP question

Posted: 2020/01/02 12:54:21
by TrevorH
I work for a VoIP provider. The only time you should need QoS set up for VoIP traffic is if your network is overloaded and the traffic needs to be prioritised in order to make it thorough in a timely manner. If you have a lot of traffic then QoS can help but I'd be tempted to set it up and see how it performs and come back to it later if you experience issues...

Re: Expand Network for VOIP question

Posted: 2020/01/02 15:57:19
by northpoint
I want to thank both of you for your opinions.

Since the network runs a 1GB speed and they have more than ample bandwidth on the internet connection I am going to first try without the added expense of a new switch. Im just not happy with the time frame I have been provided. They want this project completed by the 10th of this month. I just wanted more time to look things over.

I first was leary of posting about this here. Reason being its not really a CentOS issue. However, I am under the opinion this is where the "Big Boys" hang out :)

Thanks again for the comments - Happy New Year also :)


Re: Expand Network for VOIP question

Posted: 2020/01/03 19:17:41
by BShT

Re: Expand Network for VOIP question

Posted: 2020/01/03 20:50:10
by northpoint
BShT wrote:
2020/01/03 19:17:41
Thank you. Even though they are going 'cloud' for their VOIP this project looks very interesting.