asterisk users - Oct 2004 - RE: Asterisk on a mid-sized flat corporate

Our experience with VoIP has been that while you could use a large ping
packet to give you an idea of your network performance doing a transfer
test of a large amount of data is better.  

To do this clear the counters on your switches and then do a transfer of
10 GB of data at several times throughout the day while timing the
transfer, also check and clear the counters in between the test.  This
will give you the throughput and show you errors.  10 GB worth of data
on a Gb switch should transfer in about 1.67 minutes where as on 100 Mb
network it should transfer in about 16.67 minutes.  This is calculated
with 20% overhead for the network.  Try the transfer from a 100 Mb
connection to another 100 Mb connection where the connections are on two
different switches connected through the Gb switch.  The reason for the
100 Mb to 100 Mb connection is for extension to extension calls, also it
gives you worst case performance.  You should check the systems you are
transferring data between to make sure they are not bogged down with
other task as this could skew the results.

Checking the counters (errors, drops, collisions, etc.) gives you an
idea of your network health.  As far as not using QoS I would reconsider
if at all possible.  As long as your switches support QoS then setting
it up is not that hard.  Also if your 100 Mb switches do not support
marking but do support switch of QoS then do the marking at the Gb
switch as this will help with the delivery.  The marking of QoS on a
switch is more important from the client side as Asterisk will set the
QoS bits.  And if your switches do not support QoS then replace them
when you have the opportunity, it is only money after all.  ;)

Best regards,

 Duane Pudenz
   Senior Network Engineer
   Televerde

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Hello, all. I'm thinking of installing Asterisk at my company, and
someone asked if our current network might not have some issues. I
don't think so, but I'd like a vote of confidence to be sure. Our
network has a gigabit switch, with 6 100 Mbit switches plugged into it,
and roughly 150 ethernet connections of one sort or another. It's also
flat: no routing happening at all inside the company. Without
installing QoS, would this network be able to offer -- with reasonable
reliability -- good quality internal calls? [I'm not worried about
external, as that'll be POTS entirely.]
Thanks!
-Ken D'Ambrosio
****