[Asterisk-Users] What business IP phone to use

[Rich Adamson]

> > I have one question,
> > 
> > How does a large file transfer like your excel spreadsheet example, affect
> > communication between an Asterisk server and SIP phone?  The only possible
> > configuration I can think of that would cause a problem is if the client PC
> > is sharing the same eternet cable and therefore the same physical port on
> > the switch as the SIP phone.  Other than that or if your asterisk server is
> > also a file server (which should never be done), I don't see a problem or am
> > I missing something.
> 
> What you seem to be missing is the fact that so many people say "You 
> must have QoS on your LAN to make voice work well."  In my experience 
> that is not the case and creates needless complication on your LAN.
> 
> My general policy is "Plan for QoS on the LAN (only buy switches that 
> can do it), but only actually set it up if it's needed."  Of course, QoS 
> on a WAN is totally different.

I'd agree with that 100%. 

The issue on switches becomes very apparent when multiple switches are
involved, and a downstream switch has many PC's running at 100 meg (for
example only) contending for a 100 meg uplink (to the next switch).

In very small installations (one or two swithes), that may not cause an
issue until multipe devices attempt to do something at the same time, which
in many cases will cause rtp delays and/or dropped packets.