Tuesday, January 24, 2012

Basic Differences Between CAT5, CAT5E, CAT6, CAT6e, CAT6a Cables

  RJ45 Pin-out for Network Connection 

Basic Difference Between CAT5,CAT6,CAT6e and CAT6a Cables
Category 5
Category 5 cabling transmits at a frequency of 100MHz. This provides a rated line speed of up to 100Mbit/s and a cable segment length of 100 meters maximum. Most Category 5 cables, were designed for earlier networks replacing cat 3, only used two twisted pairs of wires. However, older Category 5 cabling continues to make up the majority of the world’s network cabling infrastructure.

Category 5e
Category 5e was later introduced as an improved specification to the very popular Category 5 that replaced Cat 3.  The improvement was in noise reduction. By reducing the noise and signal interference beyond Cat 5, Category 5e rated transfer speeds increased to 350 Mbit/s over 100 meters. The new 5e cabling standard however also required all the cabling to include four twisted pairs not just two like with Cat 5. All eight contacts has to be used. Cat 5e introduced and optimized encoding scheme that allows up to 50-meter lengths of Category 5e cable to provide at or near Gigabit Ethernet (1000BASE-T) speeds. This was during the era of the early stages of Gigabit

Category 6
Gigabit Ethernet (1000BASE-T) became mainstream and required new industry-standard cables capable of transmitting at a higher frequencies than Cat 5e to go beyond the 50 meter limitation. Cat 6e transmits at 250 MHz. The new Category 6 cable uses thicker-gauge wire to attain the higher frequencies, it has increased shielding, and more pair twists per inch to reduce signal noise and interference. The new tighter specifications introduced with Cat 6 cabling guarantee that 100-meter runs of Category 6 are capable of 1000 Mbit/s transfer speeds. As with 5e reducing the cable length can achieve higher speeds than the category types design goal so 10-Gigabit Ethernet speeds can be achieved  when reducing cable lengths to less than 50 meters.

Category 6e
The limitation of 50 meters of 10Gugabit was over come with Category 6 Enhanced (6e).  Cat 6e is an augmented specification designed to double transmission frequency of Cat 6 to 500 MHz. It has the more pair twists per inch as does Cat 6 but it's also wrapping Category 6 in grounded foil shielding, a full 10-Gigabit Ethernet speeds can be achieved without sacrificing the max cable length of 100 meters.

Category 6a
Category 6a (or Augmented Category 6) is defined at frequencies up to 500 MHz—twice that of Cat. 6 but he same as 6e. Because it is shielded, Cat 6a performs at improved specifications over 6 and 6e, in particular in the area of alien cross-talk when compared to Cat 6 UTP   Cat 6 UTP exhibited high alien noise in high frequencies.6A. To reduce the noise, 6a EA specification (not EIA/TIA) require a new generation of connecting hardware that offers far superior performance. 6A connectors performs 3 dB better than a Cat 6a connector that conforms with the EIA/TIA specification. 3 dB equates to 100% increase of near-end cross-talk noise reduction. 

More wire specifications and a practical case example use of 10GB is available at this additional location - Differences Between Category 5 and Category 6 . The use of special case cables such as cross-over cables is also covered at the same article location.

Wednesday, January 18, 2012

Exchange Management Shell Create New User with Exchange 2010 Shell

Exchange Management Shell Create New User with Exchange 2010 Shell


New-Mailbox -Name 'new user' -Alias 'nuser' -UserPrincipalName 'nuser@your-domain.com' -SamAccountName 'nuser' -FirstName 'new' -Initials '' -LastName 'user' -Password 'System.Security.SecureString' -ResetPasswordOnNextLogon $false

I used this just today and it worked very nicely. I suspect the command can be oput into a script or batch file to create many accounts without the need for exchange 2010 Managment console.