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Phil Cook wrote:
> hmm C=n(h+s)/w where the Complexity of a project is equal to the number
> of people involved multiplied by the number of pieces of hardware and
> sofware required, divided by the number of words used to describe it by
> a manager-level person.
Wait - that would imply that the complexity of a project decreases with
the wordiness of the description. That can't be right... :-P
(I prefer the "comprehension = 2 ^ -precision" that somebody here has as
their sig...)
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And lo on Thu, 08 Nov 2007 09:38:30 -0000, Invisible <voi### [at] devnull> did
spake, saying:
> Phil Cook wrote:
>
>> hmm C=n(h+s)/w where the Complexity of a project is equal to the nu
mber
>> of people involved multiplied by the number of pieces of hardware and
>> sofware required, divided by the number of words used to describe it
by
>> a manager-level person.
>
> Wait - that would imply that the complexity of a project decreases wit
h
> the wordiness of the description. That can't be right... :-P
>
> (I prefer the "comprehension = 2 ^ -precision" that somebody here ha
s as
> their sig...)
You missed the qualifer - 'manager-level'. "I just need a database to
store every transaction for the company", "Let's have all our phone call
s
going over the network?", "We'll just have one piece of software that do
es
everything?"
--
Phil Cook
--
I once tried to be apathetic, but I just couldn't be bothered
http://flipc.blogspot.com
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scott wrote:
> It makes communication between sites much more efficient and cheaper.
Unless the bandwidth between those sites is already overloaded?
--
Darren New / San Diego, CA, USA (PST)
Remember the good old days, when we
used to complain about cryptography
being export-restricted?
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Darren New wrote:
> scott wrote:
>> It makes communication between sites much more efficient and cheaper.
>
> Unless the bandwidth between those sites is already overloaded?
Made me laugh the other day - our GM says to me "when we move, we can
need more than 5 meg, can we?"
Er, actually 50 meg would be better...
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Invisible wrote:
> Darren New wrote:
>> scott wrote:
>>> It makes communication between sites much more efficient and cheaper.
>>
>> Unless the bandwidth between those sites is already overloaded?
>
> Made me laugh the other day - our GM says to me "when we move, we can
> need more than 5 meg, can we?"
>
> Er, actually 50 meg would be better...
Part of your answer might include unnecessary transatlantic traffic as
in: "If every printjob has to pass the US server we need at least 1G to
get a reasonable response. If only things like the e-mail has to cross
the ocean twice we might do with 50. If we would restrict all
transatlantic traffic to what is really necessary, 10 to 25 might
suffice for the next few years. But remember that traffic also follows
something like Moore's law. "
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> Checking online, it seems I can get to 24 or 48 port switch with gigabit
> depending on which make and model you go for.
>
What's the backplane switching speed? does it really mean you can get
all ports sending gigabit-level traffic? or simply that the clockrate
will be gigabit, but in reality, as soon as two machine get around the
200Mbps range, the whole switch, or a bunch of ports will slow down?
> Erm... what the hell?
>
> (0. So it won't be gigabit, which is virtually the entire point of
> buying new switches in the first place, so I should probably stop here.)
>
> 1. Since when does VoIP require PoE?
Because you can power your phone through the ethernet cable. Unless you
want to have a separate power cord to connect the phone to the wall
outlet. Today's ISDN or POTS phones get a 48v DC power feed down the
phone cable. With VoIP, you either need to send juice on the ethernet
cable's unused pairs, or plug your phones in the wall.
PoE is also often used to power wireless antennas.
> 2. For that matter, since when does VoIP require any special hardware of
> any kind?
Because sometimes people like to use actual phones, and actual phones
need electricity to work.
Because you need special hardware to be able to convert your internal
VoIP traffic to interface with the outside world's phone systems.
Because you need special hardware to be able to convert your fax
amchines, central alarm systems, key-card entry system, etc... that
still use analog modems to use your VoIP network.
VoIP is a lot more stuff than just installing Skype on your PC.
> 3. You want to use VoIP? Um, *why*?? Do you just enjoy extra complexity,
> or is this because VoIP sounds all shiny and new and sexy and we should
> get with it?
Because it cuts down on the amount of wiring than will go in the walls.
Because it cuts down on the number of phone lines coming in and out of
the building.
Because it can cut down on long distance calls.
etc...
Yes, for the most part, migrating to VoIP in an existing office is still
a solution looking for a problem to fix, but in a new building, the
costs of going with VoIP today are often less than the costs of building
a separate telephony and data network.
> 4. So, let me get this straight. We're currently arranging a contract to
> spend tens of thousands of pounds to have our existing ISDN digital
> phone system moved to the new building, but "in the next year or two"
> you want to throw all that in the bin and move to VoIP? Are you mental??
> You're telling us all this *now*?!?
Ok, so you'd prefer to have to scrap the current network hardware ON TOP
of replacing the phone system in a few years?
> Somebody correct me if I'm wrong, but last time I checked, VoIP is still
> an immature and very experimental research technology that isn't yet
> usable in the real world. (Unless you have absurd amounts of resources
> to throw at the problem, in which case almost anything can be made
> feasible.)
You are wrong. It is a fairly new technology (e.g. less than 10 years
old), but there are lots of people who use it everyday in the real
world. Office buildings, call-centres, schools, hospitals, etc...
>
> I can't *begin* to imagine what advantage VoIP would offer us as a
> company. (Apart from the obvious benefit that next time our Internet
> access fails, I won't be able to contact our ISP to notify them, and
> next time our VPN goes down, I won't be able to contact HQ to get it
> fixed...)
>
See above.
Besides, I'm sure in the event of a complete network outage, you'll be
able to find someone with a cell phone to contact the ISP.
> Well anyway, I'm moderately certain that our building intrusion alarm
> won't work without a real telephone line, so I guess we still need at
> least a few of those. ;-)
See above.
--
/*Francois Labreque*/#local a=x+y;#local b=x+a;#local c=a+b;#macro P(F//
/* flabreque */L)polygon{5,F,F+z,L+z,L,F pigment{rgb 9}}#end union
/* @ */{P(0,a)P(a,b)P(b,c)P(2*a,2*b)P(2*b,b+c)P(b+c,<2,3>)
/* sympatico.ca */}camera{orthographic location<6,1.25,-6>look_at a }
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Francois Labreque wrote:
>> Somebody correct me if I'm wrong, but last time I checked, VoIP is
>> still an immature and very experimental research technology that isn't
>> yet usable in the real world. (Unless you have absurd amounts of
>> resources to throw at the problem, in which case almost anything can
>> be made feasible.)
>
> You are wrong. It is a fairly new technology (e.g. less than 10 years
> old), but there are lots of people who use it everyday in the real
> world. Office buildings, call-centres, schools, hospitals, etc...
>
Small community college in middle of no where USA migrated to VoIP. For
them, it was a cost balancing act between maintaining a POTS exchange or
swapping everything out. They were already running cabling to every
office and most of the class rooms for internet connections, running
multiple cables wasn't really a cost problem. From what I saw of the
wiring closest, it actually cleaned up everything. The only trouble I
heard about was that this happened while they re-modeled the campus as
well, so their nicely designed fiber links between buildings fed the
backhoes that were doing landscaping.
Compare the cost of having and maintaining a telephone exchange. I can't
imagine the phone companies sell/rent those very cheap, when you want to
have different numbers for each phone, instead of just extensions.
>>
>> I can't *begin* to imagine what advantage VoIP would offer us as a
>> company. (Apart from the obvious benefit that next time our Internet
>> access fails, I won't be able to contact our ISP to notify them, and
>> next time our VPN goes down, I won't be able to contact HQ to get it
>> fixed...)
>>
>
> See above.
>
> Besides, I'm sure in the event of a complete network outage, you'll be
> able to find someone with a cell phone to contact the ISP.
>
Keep one telephone in the network control room. You won't need to keep
the whole PBX just to keep one line active. What it also means is that
when the network does go down inside, you don't have everyone calling to
tell you.
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Francois Labreque wrote:
>> Checking online, it seems I can get to 24 or 48 port switch with
>>
>
> What's the backplane switching speed?
Depends on the model. ;-)
>> 1. Since when does VoIP require PoE?
>
> Because you can power your phone through the ethernet cable. Unless you
> want to have a separate power cord to connect the phone to the wall
> outlet. Today's ISDN or POTS phones get a 48v DC power feed down the
> phone cable. With VoIP, you either need to send juice on the ethernet
> cable's unused pairs, or plug your phones in the wall.
Mmm. My current digital phone has a seperate power cable...
> PoE is also often used to power wireless antennas.
Wireless = massive security hole = to be avoided at any cost.
>> 2. For that matter, since when does VoIP require any special hardware
>> of any kind?
>
> Because sometimes people like to use actual phones, and actual phones
> need electricity to work.
> Because you need special hardware to be able to convert your internal
> VoIP traffic to interface with the outside world's phone systems.
> Because you need special hardware to be able to convert your fax
> amchines, central alarm systems, key-card entry system, etc... that
> still use analog modems to use your VoIP network.
>
> VoIP is a lot more stuff than just installing Skype on your PC.
So why are we bothering to do all this stuff?
POTS may not be high-tech, but it *is* legally guaranteed to actually
work properly...
>> 3. You want to use VoIP? Um, *why*?? Do you just enjoy extra
>> complexity, or is this because VoIP sounds all shiny and new and sexy
>> and we should get with it?
>
> Because it cuts down on the amount of wiring than will go in the walls.
> Because it cuts down on the number of phone lines coming in and out of
> the building.
> Because it can cut down on long distance calls.
> etc...
>
> Yes, for the most part, migrating to VoIP in an existing office is still
> a solution looking for a problem to fix, but in a new building, the
> costs of going with VoIP today are often less than the costs of building
> a separate telephony and data network.
But we *are* building two seperate networks. (And then ditching one in a
few months.)
Seriously, there is nothing in that lot that looks like a win from where
I'm sitting. Conceivably it's cheaper. But for that, you get mountains
of unnecessary additional complexity. No thanks!
>> 4. So, let me get this straight. We're currently arranging a contract
>> to spend tens of thousands of pounds to have our existing ISDN digital
>> phone system moved to the new building, but "in the next year or two"
>> you want to throw all that in the bin and move to VoIP? Are you
>> mental?? You're telling us all this *now*?!?
>
> Ok, so you'd prefer to have to scrap the current network hardware ON TOP
> of replacing the phone system in a few years?
No - my point was, if you're going to use VoIP, why bother paying tens
of thousands to set up a telephone system in the new building when it's
about to become obsolete? (I suspect it's too late to change now; since
nobody thought of telling me sooner...)
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Sabrina Kilian wrote:
> Compare the cost of having and maintaining a telephone exchange. I can't
> imagine the phone companies sell/rent those very cheap, when you want to
> have different numbers for each phone, instead of just extensions.
They do when they're selling it to an entire business park. ;-)
> Keep one telephone in the network control room. You won't need to keep
> the whole PBX just to keep one line active. What it also means is that
> when the network does go down inside, you don't have everyone calling to
> tell you.
No - they'll use SneakerNet. :-S
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> Francois Labreque wrote:
>>> Checking online, it seems I can get to 24 or 48 port switch with
>
>>> 1. Since when does VoIP require PoE?
>>
>> Because you can power your phone through the ethernet cable. Unless
>> you want to have a separate power cord to connect the phone to the
>> wall outlet. Today's ISDN or POTS phones get a 48v DC power feed down
>> the phone cable. With VoIP, you either need to send juice on the
>> ethernet cable's unused pairs, or plug your phones in the wall.
>
> Mmm. My current digital phone has a seperate power cable...
Is you wall outlet connected to the generator? Hopefully, the ethernet
switch in the riser is. This way, IP phones can still work during
power outages.
>
>> PoE is also often used to power wireless antennas.
>
> Wireless = massive security hole = to be avoided at any cost.
The bit about wireless antennas wasn't specifically about your company.
In your settings, having a wap leak confidential information on
the street might be a bad idea, but there are lots of places where being
wired causes more problems. For example in big warehouses. Having
wireless barcode readers is very handy to find the box you're looking
for while stting in your forklift truck, rather than having to get out
and go to a wall mounted terminal, and there is very little of
information leakage since warehouses are natural faraday cages.
>
>>> 2. For that matter, since when does VoIP require any special hardware
>>> of any kind?
>>
>> Because sometimes people like to use actual phones, and actual phones
>> need electricity to work.
>> Because you need special hardware to be able to convert your internal
>> VoIP traffic to interface with the outside world's phone systems.
>> Because you need special hardware to be able to convert your fax
>> amchines, central alarm systems, key-card entry system, etc... that
>> still use analog modems to use your VoIP network.
>>
>> VoIP is a lot more stuff than just installing Skype on your PC.
>
> So why are we bothering to do all this stuff?
>
In your case? I have no idea. But as Sabrina mentions in the other
message, there are situations where it makes a whole lot of sense.
Our local school board cut their telco costs tenfold by getting rid of
all the phone lines - between 24 and 200 - in each of their 1300 schools
and going VoIP with only a pool of 600 lines at the head office.
My company has a whole floor dedicated to "mobile" employees who mostly
work from home, or on the road. Each one has his or her own phone
number, but when they actually do come in the office (or any of the
company's offices worldwide), they can just log into any of the IP
phones and they'll be reached like if it was _their_ desk.
> POTS may not be high-tech, but it *is* legally guaranteed to actually
> work properly...
>
>>> 3. You want to use VoIP? Um, *why*?? Do you just enjoy extra
>>> complexity, or is this because VoIP sounds all shiny and new and sexy
>>> and we should get with it?
>>
>> Because it cuts down on the amount of wiring than will go in the walls.
>> Because it cuts down on the number of phone lines coming in and out of
>> the building.
>> Because it can cut down on long distance calls.
>> etc...
>>
>> Yes, for the most part, migrating to VoIP in an existing office is
>> still a solution looking for a problem to fix, but in a new building,
>> the costs of going with VoIP today are often less than the costs of
>> building a separate telephony and data network.
>
> But we *are* building two seperate networks. (And then ditching one in a
> few months.)
>
> Seriously, there is nothing in that lot that looks like a win from where
> I'm sitting. Conceivably it's cheaper. But for that, you get mountains
> of unnecessary additional complexity. No thanks!
>
Not "additional" complexity. Just "different" complexity. Managing a
PBX and associated paraphernalia is not really that much simpler than
managing a VoIP system and its own set of gizmos and doodads.
Deciding today to buy VoIP-ready hardware is not necessarily a bad
decision. Yes, it's more expensive than buying switches that don't do
PoE, but it's a good idea to plan ahead a little bit. Just like you
were planning on getting Gig switches, even though there isn't a single
PC or server on the market today that can sustain gig throughput for
more than a few frames at a time.
>>> 4. So, let me get this straight. We're currently arranging a contract
>>> to spend tens of thousands of pounds to have our existing ISDN
>>> digital phone system moved to the new building, but "in the next year
>>> or two" you want to throw all that in the bin and move to VoIP? Are
>>> you mental?? You're telling us all this *now*?!?
>>
>> Ok, so you'd prefer to have to scrap the current network hardware ON
>> TOP of replacing the phone system in a few years?
>
> No - my point was, if you're going to use VoIP, why bother paying tens
> of thousands to set up a telephone system in the new building when it's
> about to become obsolete? (I suspect it's too late to change now; since
> nobody thought of telling me sooner...)
There are lots of reasons (besides shortsightedness - even if it's very,
very common!) why companies will invest in a temporary solution rather
than wait for the final one to be delivered. Especially when it comes
to moving people around. For example: sometimes, leases have to be
signed for extended periods of time, and the costs associated with
breaking a 10 year lease on a building might be greater than the cost of
ripping the PBX apart in 2 years.
This being said, I have no idea how your company is handling the move to
the new facilities and why it's taking the decisions it's taking, so I
can't vouch for their sanity, but I've been through enough office moves
to know that "Geee... I wish we'd thought of this last year" is usually
very expensive.
--
/*Francois Labreque*/#local a=x+y;#local b=x+a;#local c=a+b;#macro P(F//
/* flabreque */L)polygon{5,F,F+z,L+z,L,F pigment{rgb 9}}#end union
/* @ */{P(0,a)P(a,b)P(b,c)P(2*a,2*b)P(2*b,b+c)P(b+c,<2,3>)
/* sympatico.ca */}camera{orthographic location<6,1.25,-6>look_at a }
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