QoS and VLAN's

[bero]

Hi!

I am looking for a best practice soulution for my 3CX phone system, today i've got about 6 members on the 3CX server and we are constantly bothered with echo and scrathing noises. - I suspect that it is our networking that may be the problem, we connect our phones to the switch where all our servers are connected, we also have our computers connected trough our phones (2 port switching). - I wonder what best practice is, QoS and VLAN, or is enough with just the QoS to all of our phones, and we dont have to seperate the phones from our server network with VLAN.

Internett --> Router --> Switch -QoS-> 3CX server
                                  -->    Computer
                                  -->    Computer
                                -QoS-> Phones
                                -QoS-> Phones
                                -QoS-> Phones

Or

Internett --> Router --> Switch -QoS/VLAN 1-> 3CX server
                                  -VLAN 2->    Computer
                                  -VLAN 2->    Computer
                                -QoS/VLAN 1-> Client
                                -QoS/VLAN 1-> Client
                                -QoS/VLAN 1-> Client

If someone has the answer for the best practice when it comes to this kind of setup.

 

[comresource]

It is unlikely that you are having QOS issues on the local LAN with only 6 users. Do you experience call quality problems from extension to extension or just for external calls?

If it is a LAN issue then you will need to configure QOS. The simple way is to have a switch that will trust the DSCP settings of the device connected to it and configure the queues appropriately. Most phones are already configured to tag the packets with SIP=26(AF) and RTP/RTPC-46(EF) so you may just have to tweak the switch to accept those. If you really feel the need to use VLANS there will be some adminitrative overhead with multiple subnets and possibly having to Multi-Home your BPX with one NIC for Phones and another for Desktop Connectivity (Assistant, Web Interface),.

If on the other hand the issue is external are you using a VOIP provider or a PSTN gateway? If it is a generic VOIP provider the best you can do is tag and queue the packets on your edge device and hope for the best. If it is a Business Class VOIP provider they should be able to handle QOS all the way through to PSTN.

 

[bero]

Hi and thanks for your reply!

It's as far as i can see only external calls that we get lag and echo, tested with internal calls and there is no odd sound..
I'm connected to a VOIP provider, and they should be a quality/bussiness provider. - It's the provider with the most client's in our country, so i would think it's rather an problem on our side of the phonesystem.

I've seen on different post's in this forum, that the actually calling doesnt take that much of a bandwidth from our internet connection, we are running gigabit to those computers that are capable of this, and 100mbit to the rest. - Our internet connection is around 3.5 mbit to around 4 mbit, so it shouldnt be any problem, we are however using the bandwidth quit well, and would say that we are laying in about 70 - 80 % off all our internal bandwith in office hours and peaks every day at around 95 % - So it may be that our internet connection is to low to handle both the data traffic and our VOIP phones.

Is there any tests we can run, wether it is the internet connection or our VOIP providers "fault" that we are experiencing lag and echo noises and sounds?

Once again, tanks so much for your reply!

- Fredrik / Bero