Archived from groups: comp.dcom.voice-over-ip (
More info?)
"Mitel Lurker" <wdg@[206.180.145.133]> wrote in message
news:489aq0l31n9f9l9ptoimlfn5kvq6i8stad@4ax.com...
> In article <r21aq055ng89lh8an61ic8r2itjgqta6nr@4ax.com> bob@nospam.com
> writes:
>
> >New building going in. 100 user VOIP system planned. Is Cat 6
> >recommended or is the <1Gb speed on 5e adequate?
>
> Bob, VOIP will work over Cat-3. Obviously Cat-5 is what you should use.
> Cat-6 is a holy bitch to work with, I wouldn't wish it on my worst enemy.
>
> Note well... VOIP telephones require power. This can be either
> station-side via wall warts or centralized in the wiring closet. Most
> folks use a centralized approach since they often have UPS power available
> in the wiring closet(s). Therefore the additional pairs in a standard 4-pr
> cat5 data cable are needed. I mention this because I know some places
> where folks have cheated and patched 2 data circuits into the same 4-pr
> drop cable.
some versions of power over ethernet use the spare 2 pairs, others send it
over the ethernet pairs (lst time i checked, oth were part of the IEEE
standard - but that was just before ratification).
so - whether you need 4 pairs connected depends on the Voip PoE version.
>
> Should you purchase a POE (Power Over Ethernet) LAN switch? Probably.
> Optionally purchase something like the PowerDsine 12 or 24 port inline
> power insertion unit.
last time i priced these i could buy a new stackable switch with PoE at the
same price as the power injector.
Also, using a switch with built in PoE simplifies the wiring, and cuts down
the rack space needed - both have been an issue for me before.
so if you need to replace the ethernet switches anyway (to allow you to fit
the new building while the old kit is still in the old place, or you need
new for QoS support) - then check the system costs for the various ways you
could do this.
>
> Any/all of your Etherswitches need to be capable of supporting 802.1p/q
> priority and VLAN tagging.
some switches also support QoS based on IP address, even if they are only
layer 2 - e.g. Cisco and Nortel stackables. Using IP based QoS means you
dont have to separate Voip traffic by VLAN (e.g. a PC softphone may not give
you that option)
>
> Never connect a VOIP telephone to a hub.
> Never connect a VOIP telephone to a hub.
> Never connect a VOIP telephone to a hub.
> Never connect a VOIP telephone to a hub.
> Never.....
works fine until you add data traffic and load the hub up......
>
--
Regards
Stephen Hope - return address needs fewer xxs