Lan cables....

[silicon]

It seems there are several ways to wire the RJ45 connectors to have 100 Base 1000 etc. Can I use the 1000Base T connections as default?

 

[Cerb]

There are only 2 ways. For whatever reason, B is the standard one for the computer networking.

 

[JackMDS]

The old 100Mb/sec. did not use all the pairs in the Ethernet cable. As a result some entities (like cheap ISPs, and Router vendors) use to dish out for free none standard cables.

1000 Mb/sec. (aka Giga) uses all the pairs and does not need crossover concoction.

So, as a celebration of the current 21st century use the Standard.

T568B Color as seen in the table down the page here - http://en.wikipedia.org/wiki/Modular_connector#8P8C

 

[dave_the_nerd]

Unless you absolutely need to, you're probably better off (both in terms of cost and reliability) purchasing pre-made cables.