[unisog] VOIP considerations checklist?

Peter Van Epp vanepp at sfu.ca
Wed May 21 20:35:50 GMT 2008


On Wed, May 21, 2008 at 03:25:39PM -0300, Matt Ashfield wrote:
> Hi,
> 
> We're looking at the business case for voip on campus. As part of this,
> we're trying to make sure we take into consideration all areas of the
> network which would be affected/necessary to support such a deployment.
> Things like Power, Redundancy, etc.
> 
> I'm just wondering if anyone on this list has any useful resources/links
> they could pass along. Thanks
> 
> 
> 
> Matt Ashfield
> Network Analyst
> ITS Communications & Network Services 
> University of New Brunswick
> mda at unb.ca
> 
> 
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	With the disclaimer that my own site routinely ignores me and has 
implemented VOIP my advise is keep the copper :-). I'd usually say there is
no business case for VOIP but that isn't really true we do have a few good
uses for it (travelling faculty / staff and working from home where home may
be very far away being two reasonable uses). It just sucks big time as the 
only play. You have introduced a single point of failure, with VOIP the network
being down means the entire place stops (instead of only most of it with analog
phones these days :-)) Its one potential advantage is network uptime 
statistics: "If the network is down, just pickup that VOIP phone and call us". 
Voila instant %100 uptime (at least on paper which is usually all the managers
care about :-) ). 
	Somewhat more seriously 3 or 4 years ago when we did this, the deployed
cost of the phone side of this (which ignores the network side of it) was 
twice the equivelent analog implementation. It was done anyway on the (bogus
in my view) theory that we wouldn't be able to buy analog phone gear in a few
years (in fact I expect to be long dead before that happens). Then as you note
you get in to the network costs: POE (ugh!), redundancy in the network which we
hadn't been doing because it wasn't funded. Here a UPS there a UPS everywhere
a UPS and generator. All along any network path that your VOIP calls may follow
which came as a big ugly suprise to our implementation fanboys when I pointed 
it out and in fact cancelled a deployment because the path was to expensive /
to long to secure in an appropriate time frame. Again in general our entire 
network is not life safety UPS / generatored (and maybe our entire VOIP 
installation isn't either, having pointed out the problems I figure my job is
done) perhaps yours already is, in which case this won't be an issue. Perhaps
you won't have an emergency (we haven't so far, praying that happy state of
affairs continues til I retire :-)) that is attributable to VOIP. 
	The number one fun question to ask of both your VOIP vendor and your
risk manager is "what about 911?". Get ready to see the most amazing soft shoe
dance from your VOIP vendor because this is very hard and ugly to get right.
I believe our current implementation depends on poking in to switch MIBS to
aquire the physical location of the set run the phone is currently connected
to, I don't know if anyone has ever tried it ... An appropriate (loaded) 
question for your risk manager is "if we deploy this VOIP thing which looks 
like a phone and sometimes if the network is up, acts sort of like a phone, 
how much will we get sued for if it doesn't work in an emergency?". The answer 
ours got back when he asked this at the paranoids (I mean risk managers :-)) 
convention is "There is no current case law, so you will be creating it, making 
the answer lots and yes we expect that you will lose in the end!". The one sort
of advantage you have is that being in Canada like us, as far as we can 
determine there is no law or regulation on the provision of 911 service that 
you are violating by doing or not doing something (if any Canadian is aware
of one we would be most interested in a pointer!). We can get guidelines from 
the E911 folks but they can't point us at any law or regulation that covers us,
as not a telephone company, we seem to fall between the cracks. I beleive that 
will drop us in to common law and is likely in turn to lead to that "it looks 
like a phone but isn't and you may be negligent in not pointing out it isn't a 
phone" senario. Happy VOIPing (and buy stock in the analog phone switch 
manufacturers :-) ).

Peter Van Epp / Operations and Technical Support 
Simon Fraser University, Burnaby, B.C. Canada


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