1Gbps On Existing Wiring

[owensdj]

There is a small office network that was wired several years ago and has a 100Mbps switch. Almost all of the dozen or so computers now have gigabit ethernet ports, so I'd like to replace the switch with a gigabit switch for faster network transfers. How can I tell if the existing ethernet wiring can support gigabit speeds?

 

[imagoon]

Typically it is laser printed on the side of the cables. Supporting gig takes more than the cable though, make sure to check the terminations. Cat 6a cable attached to a cat5 keystone running gig will make for lots of days of excitement and entertainment for example.

Edit: Also if you can get a hold of a fluke tester, it can give you a "ball park" because it can test the cable/jacks and see if it passes.

 

[Crusty]

Yep, you'll want all keystone jacks and cables to be at least Cat 5e and hopefully they were certified when they were installed. You can always get someone out there to check the cables.

 

[owensdj]

So if all the cables and keystone jacks were Cat 5e they'll support 1Gbps?

 

[Crusty]

Originally posted by: owensdj
So if all the cables and keystone jacks were Cat 5e they'll support 1Gbps?

It all depends on the quality of the terminations. Cat 5e can handle gigabit just fine, but if you have crappy terminations you won't be able to or you'll have reliability problems.

 

[nickbits]

I had cat 5 (not e) stuff and bought a gigabit router and ethernet cards, worked fine at 1Gbps. YMMV.

 

[Madwand1]

Cat 5 is no longer a recognized standard, but gigabit was designed with only cat 5 as a requirement. In other words, it may or may not be enough, depending on how well it was done.

 

[JackMDS]

Originally posted by: owensdj
So if all the cables and keystone jacks were Cat 5e they'll support 1Gbps?

Yes it will.:thumbsup:

Unless it is Home made Cr**y cables.

However you should know (so thata you would not get upset) that what is called Giga provides only 3 to 4 time more than 100Mb/sec. and Not 10x as the name implies.

At best with optimized peer-to-peer client OS network you can get a transfer of 48MB/sec. typically in the 30MB/sec. band.

That is regardless of cables Good Cat5e and or CAT6 it would be the same.

All of it is Only while doing LAN transfer a signal that originated on the Internet would be the same "Speed" as your current system.

 

[owensdj]

JackMDS, I'd be very happy with a 3 to 4 times increase over 100Mbps ethernet. This is actually a network with a Windows Server, so we should get better performance than peer-to-peer.

 

[redbeard1]

I've seen computers connected by cat3 cable claim to hookup at gigabit. But running some throughput tests showed that there was a drastic difference in what the actual data transfer was.

Network cards and switches negotiate data transfers by sending packets as fast as they can, until they reach a point where there is too high of a retransmit rate of packets due to dropped packets. Good cable, quality ends and punchdowns, and what sort of electro magnetic interfence the cable pass by, like flourescent lights, all have a bearing on the real throughput of network cables.

I have seen some odd issues when converting a network to gigabit. One thing being, that I've had old network printers and copiers that are 10 base only stop working on the gig switch.

That said you should see the benefit of moving to a gigabit switch.