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My company has two office locations about 200 meters from switch to switch, and at the moment the network speed between our two networks is really slow. The network is a 100Mb network with 2 intermediate switches, and we hardly have 30mb/s (theoretical) of bandwidth between them. At the moment both locations have their own server, router, IP range, and the network between the 2 locations isn't used a lot.

In a future project I'd like to recreate the whole network but I'd like to create it as a single network, all in the same IP range, with one router, one powerful server, one AD and so on...

Let's say all hardware is placed in location "A". I need to be sure that a user in location "B" will have the same network speed as if they were in location "A".

200 meters doesn't seem that long of a distance if I put 2 intermediate switches between the 2 locations, but at the moment we seem to have a lot of speed lost..

Question: Is it possible to have the same network speed between the two locations if we use the correct RJ45 cable and switch (all in a Gigabit network)?

Thanks for your advice.

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4 Answers 4

up vote 3 down vote accepted

Based on Distance I would go with Fiber between the sites to make sure that you have a maintained speed. Although you can put switches in between that really isn't the best solution. Below is a list from DSL Reports FAQ on cable lengths. As you can see to hit your 200 Meter requirement you should really be running fiber. This will eliminate the need for another repeater or switch. This can be easily accomplished with switches that support fiber or have an SFP port that a fiber SFP can be put into. An example of such a switch would be the Cisco SG200-26 24 Two of these ports have sfp adapters that you can put an SFP adapter that matches the type of fiber you have run between the buildings.

COPPER (UTP & COAXIAL) LENGTHS:

Gigabit Ethernet (over copper), 1000baseT
Length: 100 Meters
Cable: UTP (Cat5 and up ONLY)

Fast Ethernet, 100BaseTX
Length: 100 Meters
Cable: UTP (Cat5 and up ONLY)

Twisted Pair Ethernet, 10BaseT
Length: 100 Meters
Cable: UTP (Cat 3 and up)

Thin Ethernet, 10Base2
Length: 185 Meters
Cable: RG-58 type coax

Thick Ethernet, 10Base5
Length: 500 Meters
Cable: RG-58 type coax

FIBRE OPTIC LENGTHS:

10BaseFL (Multimode fibre)
Length: 2000m or 2km

100BaseFX Half-duplex (Multimode fibre)
Length: 412m

100BaseFX Full-duplex (Multimode fibre)
Length: 2000m or 2km

100BaseFX Full-Duplex ONLY (Singlemode fibre)
Length: 2-40,000m or 2-40km *(see note)

1000Base-LX
Length: 550m (62.5 or 50 multimode fibre)
3000m (10 singlemode fibre)

1000Base-SX
Length: 250m (62.5 multimode fibre)
550m (50 multimode fibre)

1000Base-CX
Length: 25m (requires new type of shielded cable)`
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I would spend the money to buy switches with proper trunking ports, and string fiber between your two locations, 200 meters isn't that expensive.

It will save you a lot of headaches, and you can concentrate on more important things.

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Can you be a bit more specific please ? Network isn't my specialty. Do you mean two gigabit switch that have fiber ports on them (one in each location) and a single fiber string between them ? –  Karnalta Feb 8 '13 at 13:44
    
@Karnalta fibers may break. Use more than one for redundancy. –  the-wabbit Feb 8 '13 at 14:35
    
Certainly, that's the easiest solution. Two gigabit switches, with at least two fiber ports each (for redundancy) and a single fiber line between them (with others pulled but unconnected, if you need to increase bandwidth, or deal with a malfunctioning cable). –  NickW Feb 8 '13 at 14:35

The maximum allowed length for Cat6 is 100m, so you should definitely be running fiber between these two closets/locations.

Have a cabling crew company run the fiber boxes and runs for you. You can use a couple of fiber links per switch and phyteam/pair/etherchannel/lacp between the two switches. Extra fiber pairs will be available for the future if necessary in the fiber boxes.

Setup would look roughly like the below (since you are new to networking):

End user-gigabit nic-cat6 cable to wall port-cat6 run to closet patch panel-cat6 patch cable to gigabit port on closet switch- Closet SWITCH-fiber gbic port on switch-fiber patch cable-fiber box-----fiber to remote closet----fiber box-fiber patch cable-fiber gbic port on switch-Closet SWITCH-gigabit port on closet switch-cat6 patch cable to closet patch panel-cat6 run from patch panel to wall port-cat6 patch cable from wall port to gigabit nic on end user desktop

(sorry faster to type then draw it out for you)

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If you have intermediate switches and all you get is 30 Mbps, something is wrong with either your cabling, your switches or the installation altogether.

That being said, 200 m is a rather long run for a copper installation. While it is theoretically possible to run it even without intermediate switches (the 100M limit is mainly based on the fact that CSMA/CD needs to define a maximum transmission latency to work and this limit would not apply if you are using full duplex links instead of half duplex ones and use higher-grade links with low attenuation), you are likely to run into the problem of having stray electric current between the two buildings due to the potential difference on the electric ground. The stray current may adversely affect transmissions and your switches' operation or lead to damage of your Ethernet equipment. Of course, it also costs you money on the electricity bill (although likely negligible).

This is why inter-building links are best run without creating an electric connection. You can either have a fiber run, as suggested by others, or, if you do not need a high-capacity-link and have line of sight between the buildings, consider using a 802.11n wireless link with unidirectional antennae which is likely to be significantly cheaper to implement if you have some good sites for antenna placement.

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