leton, what kind of problem you got with the voip delays?
are you sure is a problem of “voip”…? it will be great to know what kind of Gateways, Routers, Bridges, Switches, etc. you got on your Network and another important things like WAN access type and bandwith, QoS elements on your ISP Network or in yours, too.
by the way…. you know the matters happends when that kind of simple things don’t really work or config properly.
but it’s not a Voice over IP Technology problem the “delay”.
hope to know more about your network.