Upgrading home, office network to 1GBit

This is small article about upgrading your home / office network to 1GBit from 100Mbit.

My daily job includes interacting with people sitting in open office and sharing files stored on two file servers. Servers are one older windows based with 100Mbit ethernet card and one recent Centos based with 1Gbit ethernet card. As it happens software for designers and DTP is resources hungry and there is quite a lot of data shifting on network. In total 12 computers are used on daily basis although not everybody needs to work on file servers.

100Mbit network in theory enables transfer of data in rate of 12.5 MBytes (100/8) per second one way. You can assume 2% loss due to IP/TCP protocol negotiations and other factors which makes it 12.25MB/sec. And then you need to take into account other factors which can significantly reduce speed:

• wiring, type of cable used for wiring
• cross or straight wiress
• possible interaction of electromagnetic emitting appliances with wiring
• routers and / or switches
• ethernet cards in computers and hardware (especially hdd, raid cards etc)
• load on server or client

In reality after some time you can see speeds on 100Mbit network to degrade to approximately 80-95% of potential bandwidth. If you have to move or save files in between 20-100MB it is getting painful, frustrating and non efficient especially in peak times to work over network. This day it is quite easy to buy hardware which support 1000 Mbit or 1GBit data transfer rates. So it is quite easy to move on. Or is it?

What we are talking about:

1GBit speed in theory means transfer of 125MB per second. That is one DVD in app. 34seconds. Even if you drop the speed to 80% we are still talking about 102.4MB per second.

Server and clients:

You need to make sure that computers in network are capable to handle such a data traffic. To sustain 120MB/sec rate you need to have better hard drive (ideally SSD) or as it is more ususall these days more hard drives in RAID. On server side you need to have even better hardware usually including hardware memory backuped RAID card to be able hande more clients simultaneously, ethernet card or two cards with good chip and cache. Network card should have minimum impact on processor - so you would like to have ethernet card with full duplex and good chip - Intel Pro/1000GT (around 30GBP) or better as standard choice.

Switch:

This is very important. As computers are usually connected through switch and behind it to router with firewall - you will need decent equipment. It needs to handle 1GBit on each port, mix 100MBit / 1Gbit (if older appliance is attached to network)  without affecting other ports, have solid memory buffer (2MB and more), if it is managed even better. It needs to be non affected by internet connection from router as well. At the time of writing of this article suitable switches start at around 240GBP, with medium ones (possibly small Cisco) at around 500GBP.

Wiring:

Wiring needs to be good as well. Cat5e is a minimum, CAT6 cable is for peace of mind. The best if it is professionally assembled cable with certified speed - those are tested on special equipment. 15m of Cat6 assembled cable cost around 10GBP. These days it is also convenient to buy few hundred of meters roll of Cat5e / Cat6 cable and cut it and assemble RJ45 jacks as needed. If you go this road you need to make sure all pins are correctly positioned, trim the jacket of cable back and untwist pairs only for app. 18mm. Make sure end points of cable are not in close distance from possible electromagnetic interference (AC supply etc). Or invest in shielded and higher frequency tested cable. On older wiring it is quite common that cable is damaged or RJ45 jacks are damaged, so it is better to refit it with new ones.

Testing:

Ideally you will have special testers or certifiers for testing like this. Those are not cheap - you can expect for decent piece of equipment to cost around 1,000USD.

If you don't have tester you just unplugged everything from switch (even router  and internet) and you plug computers into it one by one every time testing speed between plugged computers to detect if any of them is bottleneck for your network.