atcomsystems.ca/forum Forums VOIP Phones & IP PBX VoIP & Cloud Phones, Hosted PBX, General IP Phones VOIP Questions??

Would you say that a PC (voice server ?) would work best if connected to a switch(s) then to the IP phones, not on the data network? I'm thinking there would be less interference.

If the network is properly set-up with QoS Switches and distributed correctly then having voice and data traffic on the same network isn't much of a problem.

The bigger problem is most networks aren't set-up right or the people setting them up have no clue so it's easier to buy a second switch and segregate them then to figure it out.

So, a second network on a seperate wire? Like a TDM phone system? So, Kumba is saying TDM is better than VoIP? :toothy:

Of course if you're talking about $4,500.00+ for a Cisco 48-port POE switch that can get pricey. Not to mention the added cabling necessary.

I don't have experience with VoIP, but I wouldn't think bandwidth would be much of an issue on the local side if you've got 100Mbit connections to the desktop. Controlling the broadcast domains with VLANs is certainly good practice. Is QOS on the switch side really necessary?

There is a lot of hidden costs with VOIP like QOS,POE switches, other than that you have those nasty little power supplies to the phones. until it has real benefits having telephones on the network I still recommend pbx's with gateways or ip extension cards for off site equipment

Like plumbers say, "it rolls downhill". In this case, it needs to roll uphill. The proverbial "weakest link in the chain" thing. You can have everything high and tight on the premises, but if the service provider can't offer the same level of quality via their network, then you just threw four grand out the window for a fancy POE switch.

QoS is something that is easily managed for a price on-site. The problem is, once the call traffic leaves the premises, it's anyone's guess via the public Internet. A call from Boston to New York may pass through Prague and Cincinnati on the way through Moscow to get there. There are a lot of outside influences that need to be taken into account when considering VoIP.

It's not that the concept of VoIP is bad; it's just not "good" yet due to the outside influences.

I prefer the Netgear FS728TP or FS752TP POE Switches for IP Phones. Feel free to google for prices. They are about as close as I can get to an HP ProCurve and they hands down beat the Linksys SRW224P or any of the d-link/etc switches. They also feature the lifetime warranty like the ProCurve's. If you have a need for more switch then what that offers then you should look at something serious like an HP ProCurve or Foundry Networks. I am not a cisco fan as I find their products to be convoluted and over-priced for the feature set that they come with. This is my opinion and your mileage may vary.

Now back to the regularly scheduled post:

Even with VLan's you can still have a group of servers pounding all the bandwidth in the switch or it's up/down links. The QoS and traffic shaping/prioritization scheme's let you guarantee the VoIP traffic always makes it. You can make all this easier by selecting switches that are "Stackable" and "Centrally managed". This allows you to set the network environment for all switches as one big switch.

If you have a PoE Switch you will not need the Power Supplies.

VoIP is not the end all be all by any means, but it is no longer as costly as it was a year ago.

This is why I framed my questions toward a scenario using voice T1s not the internet for trunking. (Or at least I tried to, was I unclear about that?) The idea of sending business phone calls over the internet gives me the willies.

Kumba,
Have any downtime last year? I'm thinking about it because I just did a survey and that question came up. We had 0 downtime on our Avaya G3r. Data servers have all had some kind of of service interupting downtime. The PBX NEVER has to be rebooted. AUDIX voice mail does every 60 to 90 days. I think it is Linux or some variant of Linux. Pretty reliable though overall.

I did a hop trace on a public call from my office to Florida on an IP phone across the public network...San Antonio to Dallas to LA to Honolulu to Hong Kong to God only knows where finally terminating in Sarasota. Pretty amazing... something about the shortest distance between two points is a straight line goes out the door in unmanaged VoIP world.