# if needed develop a Hybrid network for a big lab(s) or biz, then how calculate the to

Discussion in 'Computing and Networks' started by lse123, Apr 29, 2010.

1. ### lse123 Thread Starter Active Member

Oct 17, 2006
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if needed develop a Hybrid network for a big lab(s) or biz, then how calculate the total network diameter?
Ethernet Hybrid Diameter?
if I have 3 buildings(=rooms) in series(1 floor one + 2 floors others) each 200m and want to network in each 8PCs (total 32PCs) and router is on the one edge of series and exist PCs on the other edge of, then if use 100baseT in ALL rooms with 2 repeaters EACH(rule:diameter 205m) may still get bigger than this total external diameter with hybrid it, eg fiber (or 10base2) ?

Only Routers(NOT Switches/Hubs) carry external(outside, not these kept for inner LANs) IP Addresses, correct?

2. ### lse123 Thread Starter Active Member

Oct 17, 2006
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So, I must use max segment length(of a technology) rather diameter... in calculations to find max diameter in hybrid networks[100baseT+10base2]...correct?

3. ### retched AAC Fanatic!

Dec 5, 2009
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Yes, that is correct. Has the idea of running fiber crossed your path?

And how close to central is your main network cabinet?

With fiber, you will not be as constrained by distance.

From cabinet to far points, a fiber run. Then use 100baseT to the branches.

4. ### lse123 Thread Starter Active Member

Oct 17, 2006
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The backbone cable(eg fiber or else) must be one...? eg if I have a building in "X" shape, with 4 buildings and router/main-switch is on one edge and exist PCs everywhere in "X" shape...? Or may implement two backbone cables...the distance in each branch(of "X" totally) is 240m...(total 4 branches)...

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If you are using an 'X' layout, I would but the main cabinet in the middle of the X and run 4 backbones to each leg.
That will be only 120m legs.

You can have as many backbones as your router has room for.

The main core is the networking cabinet. Then you run from there, your backbones.

Typically when I set up a network layout, I use a "backbone" to each "department" and have a sub-station (switch) there to divide the "department" line into (Department1, Office1) (Department1, Office2)..... (Department1, Office11)

The next backbone, will run to another department and split again from there.

If you had enough expensive switches, you could run a backbone to every PC.

But, cable is expensive. So you want to use the 'GOOD' stuff as trunk lines, and you can use the 'budget' stuff for inter-department stuff.

If all the buildings are line-of-sight, You could also consider wireless.

This way, the "backbones" are all antennas, and you set up a sub-station in each building connected to the antenna. Then from there, Its the same.

It is easier to do in steps.

First, just GET the network there. Meaning just get connectivity to the building.
Then it is pretty straight forward.

6. ### lse123e New Member

May 10, 2010
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if I have an area 2,5 sqr miles (factory) and what to spread 4000PCs & 150 Servers, with ethernet 1000baseT backbones and PCs 100baseT , can I, total ethernet diameter permits it...?

7. ### retched AAC Fanatic!

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Can you what?

Is it possibile? Yes.

Just look at the internet. It surrounds the Earth. 2.5sq miles is nothing.

8. ### lse123 Thread Starter Active Member

Oct 17, 2006
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total ethernet diameter permits it for only 1000baseT / 100baseT... if under one netwotk id...
how many segments 1000baseT of (max segment) 100m permited?
also for 100baseT?

9. ### retched AAC Fanatic!

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You will have to use an addressable router to continue along the 100m. And you can have 65,536 address over 100baseT. So that is the limiting factor per IP (using 10bit IP4).

The distance is only a factor of the signal strength. Every 100m you can add a 'repeater' that will send your signal an additional 100m. You can do this until you use up all 65,536 address, or assign a new IP.

The copper wire is the limiting factor. with Fiber, you will get longer runs. Depending on the fibers diameter, it is ~220m to 550 meters.

10. ### lse123 Thread Starter Active Member

Oct 17, 2006
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I have a text that says some limiting data for 100baseTX

THIS IS THE SAME AS 100baseT? Or 100baseT/1000baseT are limited ONLY by 65,536 address? basically 'unlimited'...

100baseTX
max segment 100m
max diameter 205m
max repeaters 2
RJ-45

11. ### retched AAC Fanatic!

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They and tx and so on use the wire pairs in the cable differently and they use differend voltage based coding protocols.

So the way they talk is different, and the number of wires in the cable are different.

1000baseT uses 4 pairs (8 wires) for transmit and receive lines. This is one of the reasons 1000baseT is faster. There are more conductors being used to trnasmit, so there is wider bandwidth. You dont have do cram as much info on 2 pair, and worry about the emf corrupting the data stream.

12. ### lse123 Thread Starter Active Member

Oct 17, 2006
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So you mean 1000baseT/100baseT have no limits in distance - diameter(segment only limit? how-much?), and with ease cover all the metioned distance? correct?

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Well, As long as you hit a computer, or processor based repeater, you can go on forever. You sould use a repeater every 100m for copper. you can run much further with fiber with no repeater necessary.

If you are talking about 1 run between 2 routers or computers, then you are limited by the copper losses to 100m. If there are computers along the route to relay the packets, you can go around the world, 100 meters at a time. with copper.

14. ### lse123 Thread Starter Active Member

Oct 17, 2006
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if I had distance 1500m and many servers[50-150], then servers may used with repeater/switch function?

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as long as you have 1 computer or switch/repeater every 100m you are good.

100m is the maximum cable length between each powered repeaters, switches, servers, or computers.

As long as you have 1 computer repeater every 100m, you can chain them around the Earth.

16. ### lse123 Thread Starter Active Member

Oct 17, 2006
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Today's ethernet networks we mention here[1000baseT/100baseT - RJ-45] are broadband in nature or baseband? May mixed PCs send messages simultaneously to each other and internet, all to same network part, under one switch, for example...?

17. ### lse123 Thread Starter Active Member

Oct 17, 2006
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here I refer to difference between CSMA/CD vs 802.7 ? most today LANs/HOME-LANs What are? all move to 802.7...?

I see in textbooks 100baseT diameter 200m(segment 100m) well, only a Switch can extent the diameter, but to extent segment can use repeaters, transceivers, hubs, switches?

Last edited: May 16, 2010
18. ### retched AAC Fanatic!

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Yes. A SINGLE UNINTERRUPTED segment with copper RJ-45 is 100m. So If you only had 2 computers, and 1 cable, you would loose packets and efficiency because the power involved in transmitting is effected to the point of failure by the losses in the copper, in runs over 100m.

So for instance, if an ethernet card transmits at 150ma, and copper has a drop of 1ma per meter, the signal strength would be around 50ma after 100meters. And say a ethernet card cannot read a signal under 50ma.

So if you have a repeater at 100m, it will take the 50ma signal and re transmit it at 150ma agian, giving you another 100 meters before the signal degrades too much.

I pulled these numbers out of the air. This is just an explanation on the physics behind the transmission operation

19. ### lse123 Thread Starter Active Member

Oct 17, 2006
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can extent the diameter and with hub, or hubs are only for segment extension(to make a diameter)?

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If they are non powered, then NO. they can be used to make the 100m, by connecting 10 ten 10m cables, you get your 100m but without a powered repeater, the hub will not extend the range.