| Author |
Message |
Rich Seifert
Guest
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 Posted:
Wed Dec 08, 2004 4:06 am Post subject:
Re: gigabit pricing |
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In article <pMadncIUpcbBfyjcRVn-1A@rogers.com>,
James Knott <james.knott@rogers.com> wrote:
| Quote: | Rich Seifert wrote:
My point is just that there is no technology reason to build switches
in multiples of 8 ports.
Other than chip set configuruations or other hardware packaging issues. For
example blocks of four RJ45 connectors are common. Other connector block
sizes, such as 5 or 6 are less common. If you look at a 5 port gigabit
switch, you'll see a block of 4 connectors and a single connector, even
though they may be right next to each other.
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Which is the "cause" and which is the "effect"? Do manufacturers make
RJ-45 connectors in "4-packs" because equipment designers often build
switches in 4-port, 8-port, 12-port configurations, or is it the other
way around?
--
Rich Seifert Networks and Communications Consulting
21885 Bear Creek Way
(408) 395-5700 Los Gatos, CA 95033
(408) 228-0803 FAX
Send replies to: usenet at richseifert dot com |
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J. Clarke
Guest
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| Posted:
Wed Dec 08, 2004 6:05 am Post subject:
Re: gigabit pricing |
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Walter Roberson wrote:
| Quote: | In article <usenet-B5787C.08140307122004@news.isp.giganews.com>,
Rich Seifert <usenet@richseifert.com.invalid> wrote:
:I am always perplexed why people think that an 8-port switch is somehow
:more "natural" than 5, 6, or 10 ports. (The implication in the quote
:being that it is desirable to build 8-port switches.)
:I understand that powers-of-2 are "naturally efficient" sizes for
:building *memory*, because the address space is log2 of the memory
:space. However, the number of ports on a communication device is not
:related to memory space, or powers-of-2.
No, but the number of ports is naturally multiples of N, where N
is the number of ports per chipset. Gigabit chipset designers happen
to be working at 1, 2, or 4 ports per chipset. I don't have any experience
with chipset design to know whether there are advantages to even numbers
or powers of 2 at the chipset level.
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<http://www.netgear.com/products/details/GS605.php>
<http://www.linksys.com/products/product.asp?grid=35&scid=42&prid=528>
<http://www.dlink.com/products/?sec=1&pid=229>
<http://shop1.outpost.com/product/3887857?site=sr:SEARCH:MAIN_RSLT_PG>
<http://www.planet.com.tw/product/product_dm.php?product_id=180&menu_id=2>
<http://www.lantech.com.tw/eng/products/index.php?mode=view&id=71>
<http://www.trendware.com/products/TEG-S50TXE.htm>
<http://www.jaht.com/products/switch/js3005gd.htm>
<http://www.justec.com.tw/jgs500e.htm>
<http://www.zyxel.com/product/model.php?indexcate=1052791880&indexFlagvalue=1028014886>
<http://www.smc.com/index.cfm?event=viewProduct&localeCode=EN_USA&cid=6&scid=&pid=1138>
Most of them in stock starting at under $50.00.
It is clear that _somebody_ is making a bargain basement 5-port gigabit
chipset.
--
--John
Reply to jclarke at ae tee tee global dot net
(was jclarke at eye bee em dot net) |
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glen herrmannsfeldt
Guest
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| Posted:
Wed Dec 08, 2004 12:01 pm Post subject:
Re: gigabit pricing |
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Rich Seifert wrote:
(snip)
| Quote: | I am always perplexed why people think that an 8-port switch is somehow
more "natural" than 5, 6, or 10 ports. (The implication in the quote
being that it is desirable to build 8-port switches.)
I understand that powers-of-2 are "naturally efficient" sizes for
building *memory*, because the address space is log2 of the memory
space. However, the number of ports on a communication device is not
related to memory space, or powers-of-2.
|
I think eight is a good size for a small box. The 24 and 48
port are rack mount size, but eight would be a waste of
rack space. Also, if one is comparison shopping it is hard
to compare if all companies make different numbers or ports.
(snip)
| Quote: | The "naturally correct" number of ports for a switch should be logically
related to the statistics of workgroup size. For example, if 95% of
workgroups comprise 10 machines or fewer, then an 11-port switch (10 +
uplink) would seem "natural". (I am not saying these numbers are
correct; I am just showing the logic.) Of course, different port
configurations will be more or less efficient in various application
settings.
My point is just that there is no *technology* reason to build switches
in multiples of 8 ports.
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Also, workgroup size changes fast enough that you want some
extra ports. Five might be a good size for a single small
office, and eight for the next increment from five.
-- glen |
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James Knott
Guest
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| Posted:
Wed Dec 08, 2004 10:45 pm Post subject:
Re: gigabit pricing |
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Rich Seifert wrote:
| Quote: | In article <pMadncIUpcbBfyjcRVn-1A@rogers.com>,
James Knott <james.knott@rogers.com> wrote:
Rich Seifert wrote:
My point is just that there is no technology reason to build switches
in multiples of 8 ports.
Other than chip set configurations or other hardware packaging issues.
For
example blocks of four RJ45 connectors are common. Other connector block
sizes, such as 5 or 6 are less common. If you look at a 5 port gigabit
switch, you'll see a block of 4 connectors and a single connector, even
though they may be right next to each other.
Which is the "cause" and which is the "effect"? Do manufacturers make
RJ-45 connectors in "4-packs" because equipment designers often build
switches in 4-port, 8-port, 12-port configurations, or is it the other
way around?
|
Yes. ;-)
Actually, it's hard to say. The switches and hubs I've seen, tend to be
multiples of 4, except those 5 port ones. Is it due to chip design? I
read an article in Linux Journal, a few years back. I seem to remember the
chip mentioned in the article, had 4 ports and a "bus" interface, which
could also be used as a port. I don't know the history of these devices,
but I wouldn't be surprised, if there was something that at one point made
multiples of 4 a good choice. The industry is full of this sort of thing.
For example, in the telcom world, a channel bank (used to connect voice
circuits to a T1) has 24 channels (in North America), so everything that's
designed to work with it, has 24 voice circuits. Then when you get to
DS1-DS3 multiplexors, the magic number is 28. Again, all the patch panels
etc., will have 28 circuits. I don't know how those numbers were
originally derived, but I bet it made sense to some engineer at that time,
possibly due to the use of some other device. In another message, you
mentioned 25 pair cable for phone systems. Prior to those channel banks
(mid 60's) 25 pair cables were not so common, as the older analog systems,
came with various numbers of channels. |
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Damian Menscher
Guest
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| Posted:
Wed Dec 08, 2004 10:49 pm Post subject:
Re: gigabit pricing |
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James Knott <james.knott@rogers.com> wrote:
| Quote: | Rich Seifert wrote:
In article <pMadncIUpcbBfyjcRVn-1A@rogers.com>,
James Knott <james.knott@rogers.com> wrote:
Rich Seifert wrote:
My point is just that there is no technology reason to build switches
in multiples of 8 ports.
Other than chip set configurations or other hardware packaging issues.
Which is the "cause" and which is the "effect"? Do manufacturers make
RJ-45 connectors in "4-packs" because equipment designers often build
switches in 4-port, 8-port, 12-port configurations, or is it the other
way around?
Yes. ;-)
Actually, it's hard to say. The switches and hubs I've seen, tend to be
multiples of 4, except those 5 port ones. Is it due to chip design?
|
If your theory about the industry feedback forcing itself into some
chicken/egg scenario for multiples of ports is correct, then why are
we still in a situation of hotdogs being sold in 8-packs, while the
buns are in 6-packs?
Damian Menscher
--
-=#| Physics Grad Student & SysAdmin @ U Illinois Urbana-Champaign |#=-
-=#| 488 LLP, 1110 W. Green St, Urbana, IL 61801 Ofc:(217)333-0038 |#=-
-=#| 4602 Beckman, VMIL/MS, Imaging Technology Group:(217)244-3074 |#=-
-=#| <menscher@uiuc.edu> www.uiuc.edu/~menscher/ Fax:(217)333-9819 |#=-
-=#| The above opinions are not necessarily those of my employers. |#=- |
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Guest
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T. Sean Weintz
Guest
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| Posted:
Thu Dec 09, 2004 12:35 am Post subject:
Re: gigabit pricing |
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William P.N. Smith wrote:
Now if only they made a GIG version.... |
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James Knott
Guest
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| Posted:
Thu Dec 09, 2004 4:01 am Post subject:
Re: gigabit pricing |
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Damian Menscher wrote:
| Quote: | If your theory about the industry feedback forcing itself into some
chicken/egg scenario for multiples of ports is correct, then why are
we still in a situation of hotdogs being sold in 8-packs, while the
buns are in 6-packs?
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You must have different standards where you live. Here, they're 8 buns and
12 dogs to a pack. ;-) |
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Erik Freitag
Guest
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| Posted:
Thu Dec 09, 2004 8:25 am Post subject:
Re: gigabit pricing |
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On Wed, 08 Dec 2004 14:09:43 -0500, wrote:
Like I said:
| Quote: | Power is a problem - I've seen
some 100TX switches that are wallplates that use power over ethernet, but
of course, that's copper. They also were not compatible with Cisco's power
over ethernet.
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These are the very wallplates I was thinking of ... |
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Erik Freitag
Guest
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| Posted:
Thu Dec 09, 2004 8:30 am Post subject:
Re: gigabit pricing |
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On Wed, 08 Dec 2004 18:01:46 -0500, James Knott wrote:
| Quote: | Damian Menscher wrote:
If your theory about the industry feedback forcing itself into some
chicken/egg scenario for multiples of ports is correct, then why are
we still in a situation of hotdogs being sold in 8-packs, while the
buns are in 6-packs?
You must have different standards where you live. Here, they're 8 buns and
12 dogs to a pack. ;-)
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Well, the least common multiple is 24 for both of you, so there's really
no difference. Obviously, you're supposed to buy more than one package.
Didn't they cover this in "how to be a good consumer and make the economy
grow at your expense" class? |
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