Rôgêr <(E-Mail Removed)> wrote:
>Lucas Tam wrote:
>> Rôgêr <(E-Mail Removed)> wrote in news:9uudnU_KBePVKrXfRVn-
>> (E-Mail Removed):
>>
>>>> The T1 maybe a problem... A WiFi Access Point (802.11b) can
>>>> sustain about 5mbps and that would saturate your T1 5x
>>>> over. So make sure your router or access point has the
>>>> ability to throttle the connection down to 512kbps.
>>>
>>> What in blue blazes are you talking about? If the T1 is
>>> slower than the AP, I don't think any throttling is going to
>>> be necessary. How do you saturate a 5 meg network with half a
>>> meg of bandwidth?
>> A T1 = 1.5mbps
>> 802.11b AP = ~5mbps
>> 5mbps / 1.5mbps = 3x
>
>Yes, that means there is room for 3 T1s on that network. Having
>less than the maximum doesn't saturate it.
There is not enough room on the T1 to hold all the potential
traffic originated by the wireless network going towards the
Internet.
As he said, the *T1* will be saturated.
>> The WiFi network will saturate the T1.
>> What in blue blazes are YOU talking about?
>>
>I know you mean well, but you really are looking at this
>backwards.
He isn't.
>The data stream coming in at 1.54Mbs is not going to
>get saturated by having 5-7Mbs of bandwidth headroom.
The traffic going out could be as much as 5-7Mbs, and *that*
is going to saturate the 1.5Mbps T1.
Incidentally, to be pedanic, it should never be called
"1.54Mbs". It actually will deliver a payload of 1.536Mbps,
hence it is commonly rounded off to 1.5Mbps. The raw data rate
on a T1 is 1.544Mbps, and saying it is 1.54Mbps suggests the raw
rate, not the payload, or framed, rate. Unframed would deliver
1.544Mbps, but nobody in their right mind does that (which is
to say, only the US Government orders unframed T1 service).
Besides, it isn't a T1 either! It's a DS1.
(Is that enough pedantry for one afternoon?)
>If you
>want to look at the old standby plumbing analogy, this is like
>saying a 3/4" water supply pipe is going to overload a 2" pipe
>because the 2" pipe is much bigger.
Water pipes are half duplex, and our T1 is full duplex while the
wireless network is simplex. In other words, there are *two*
3/4" pipes, not one.
In addition to the 3/4" supply, there is a 3/4" backflow pipe.
That 2" pipe has a couple valves and it can drain water from one
pipe, or supply water to the other. Obviously the 3/4" supply
line won't saturate the 2" pipe... and just as obviously the 2"
line *will* saturate that 3/4" backflow line.
--
Floyd L. Davidson <http://web.newsguy.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska)
(E-Mail Removed)