What is a Mux? or a multiplexer

michael_knightmichael_knight Member Posts: 136
Some guys at my job were talking about Multiplexers. I didn't want to sound stupid so I just listened. Can someone tell me what it is?


  • astorrsastorrs Member Posts: 3,139 ■■■■■■□□□□
    In telecommunications and computer networks, multiplexing (also known as muxing) is a process where multiple analog message signals or digital data streams are combined into one signal over a shared medium. The aim is to share an expensive resource. For example, in telecommunications, several phone calls may be transferred using one wire. It originated in telegraphy, and is now widely applied in communications.

    The multiplexed signal is transmitted over a communication channel, which may be a physical transmission medium. The multiplexing divides the capacity of the low-level communication channel into several higher-level logical channels, one for each message signal or data stream to be transferred. A reverse process, known as demultiplexing, can extract the original channels on the receiver side.

    A device that performs the multiplexing is called a multiplexer (MUX), and a device that performs the reverse process is called a demultiplexer (DEMUX).

    Inverse multiplexing (IMUX) has the opposite aim as multiplexing, namely to break one data stream into several streams, transfer them simultaneously over several communication channels, and recreate the original data stream.

    Multiplexing - Wikipedia, the free encyclopedia
  • Panzer919Panzer919 Member Posts: 462
    We use it in our fiber for our Sonet ring and last mile to the customer. It allows you to carry multiple fiber customers down the same trunk line. The light travels in different frequencies(channels) so that no one connection intersects another. Once the light hits the MUX, induvidual channels are broken out and hooked into our 4500 via SFP's. The reverse is the same with the exception that we also apply filters in the field. The filters stop us from sending all wavelengths to all customers.

    Here is an example of the channels - http://www.made-in-china.com/image/2f0j00yBATONPzGLqJM/CWDM-16-Channels-Dual-Fiber.jpg

    This is how it looks going through the fiber - http://www.kvh.co.jp/en/img/data/img_dwdm.jpg

    Here is a DeMUX, a MUX looks the same though. http://www.tulsat.com/ProductImages/ProductLarge/Prisma_DWDM_Passives-751019-1.jpg

    This isnt the one we use but here is a product sheet one a MUX/DeMUX - http://www.jdsu.com/product-literature/CWDM_ds_lab_tm_ae.pdf

    Also this is a good book on Fiber if your interested - Half.com / Books / Introduction to Fiber Optics
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  • joshgibson82joshgibson82 Member Posts: 80 ■■□□□□□□□□
    Some guys at my job were talking about Multiplexers. I didn't want to sound stupid so I just listened. Can someone tell me what it is?

    Have you tried your friends at google.com? There is a wealth of info out there for things like that.
    Josh, CCNP CWNA
  • kryollakryolla Member Posts: 785
    MUX are usually located on the telco end. They bring in fiber from the street which is connected to many point of presence or POP which form a ring. The MUX can be anywhere from OC48 to OC192 and brings it down to a T1 or ethernet but here in my office they only bring it down to a T3. So a MUX is just combining multiple signals into 1 and on the other end its just reverse it goes from 1 signal to multiple. Do a search for cisco ONS 15454 that is one of the MUX we use here.
    Studying for CCIE and drinking Home Brew
  • APAAPA Member Posts: 959
    I re-iterate the research...

    Have a read up on WDM technologies... Specifically CWDM & DWDM

    CCNA | CCNA:Security | CCNP | CCIP
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