January 20th, 2003 09:40 AM
Fiber Optic Networks
I'd like to post something about optical networks, because it are the arteries of all the networks out there, and are relevant knowledge to anyone who knows or want to know something more of networking and OSI-Model. We all use them every day.
A simple traceroute can let you see if there are for example underseas optical cables,...
We all know that for example all sorts of routers troughout the world are connected with fiberoptic networks.
These fiberoptic networks make the internet possible the way we know today, make it possible that routers and other equipment can communicate with each other.
We can situate these networks actually in Layer 1 and 2 of the OSI-model.
The most used technologies are SDH ( Synchronous Digital Hierarchy) and DWDM ( Dense Wavelength Division Multiplexing ).
DWDM is one of the latest techniques with a speed rate of n * 10 Gb/s. The n-variable is equipment depending of how many 'colors' are used as channels to transport each 'color' up to 1* 10Gb/s data. These colors are coming from the basic principle of putting light trough a prisma, which reflects different colors out of the light. These 'colors' are related to a frequency an then send over the fiber-optics.
SDH is , i think, over the world the most used technique of transporting data/voice and of course internet solutions. Most of the time SDH is used after the big DWDM core-networks,
actually to make smaller but more concentrated networks over countries, regions, ...
These SDH-equipments are generally used to connect providers , telco's and companies who access the internet.
All of the fiber-optic links are so constructed to make rings, and improve network stability.
Every link is set up with a optical transmitter and receiver (Tx and Rx) at both sides of a link.
One link generally is made over one pair of fibres, and has in SDH - networks a rate of 2,5 Gb/s or lower.
Some abbreviations :
STM : Synchronuos Transfer Module ( is seen as the highway )
STM-1 : Rate of 155 Mbit/s
STM-4 : Rate of 622 Mbit/s
STM-16 : Rate of 2,5 Gb/s
STM-64 : Rate of 10Gb/s
VC-4 : Virtual Container at bitrate of 155Mbit/s ( is seen as the truck with data payload )
VC-3, VC12, VC11 are lower bitrates which are eventually put in the VC-4 truck.
I will also put in an attach that is useful if you want to know more about this topic.
Hope it is useful to your knowledge,
January 26th, 2003 02:10 PM
Would it be advisable to have more info on this topic ?
If anyone wants more were this came from, just let me know.
If you want this tut better situated, I would suggest the tut from Negative concerning
the OSI- model => http://www.antionline.com/showthread...hreadid=133897
January 8th, 2005 03:43 PM
Hello. I'm from Russia.
Can you tell me where i can read more about fiber optic networks on english?
January 8th, 2005 05:51 PM
January 8th, 2005 06:32 PM
.: Shrekkie :., Thanks! I've forgot this word - 'tutorial' .