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VoIP Network Design

Dan Torres
Level 1
Level 1

Hi everyone,

I’m seeking advice in designing voip network. Is there any reason to stick with the following:

1. one network

2. one Ethernet cable run to each cubicle for both data and voice

3. setup QoS on a router/firewall

When we can run two Ethernet cables to each cubicle (one for data and another one for voip)?  There will be two networks and QoS wouldn’t be setup on the phone network (it will be used just for voip traffic)

4 Replies 4

paolo bevilacqua
Hall of Fame
Hall of Fame

If using own cable, QoS is not a problem at all, and there is no reason to worry about it.

thank you for the reply. do you know if it possible to setup QoS for phones when i have port based vlan setup?

As above, no need to worry abot QoS on LAN.

Joseph W. Doherty
Hall of Fame
Hall of Fame


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Just to clarify, when you write of running two cables to each cubicle, one for data and one for VoIP, the two sets of traffic never share a link (or device)?  For example, both those links wouldn't terminate on the same device?

If any part of the network infrastructure shares physical resources with both the data and VoIP traffic, there's a chance the data traffic might be adverse to VoIP.  If there's any physical resource sharing, QoS might be configured to guarantee resources to VoIP traffic over data traffic.

As LANs often have ample bandwidth, and it's often easy to provide more bandwidth, if necessary, you might not need to utilize QoS to have acceptable VoIP.


BTW, older hosts used to have TCP stacks that would cap their bandwidth utilization on high speed LANs.  Newer TCP host stacks can often drive even 10g host links at full utilization.  QoS might be needed where it didn't used to be needed.