wumply
August 25th, 2005, 18:29 PM
I read that while DSL lines are copper twisted pair lines from the DSL company (phone company?) all the way to the subscriber (and you have to be within strict short distances). I also read that cabale com[panies can combine transmission methods..."they can use fiber optics to connect neighborhoods but use copper coax wires to go from the user's home to the street.
Now what I don't understand is this. Fiber Optic cables allow very, very fast download data transmission (slowing down if the net is busy, busy.) But copper co-ax, comparatively, is much slower, right? Let's assume I get fiber optics to the street and then copper wire into my house. (I am using broadband).
Why doesn't (or 'wouldnt') the last few feet of the copper wire (say 75 feet) from the street to my house force, say, a big file (say 11 MB on up to 30-40 mb or more) to slow down tremendously, noticeably? So you only have 75 feet of a slow road but would it not take you much longer, say than the same file, coming all the way from San Francisco when you're in New England?
Can someone bring me up to speed on the answer to my question?
Big Booger
August 28th, 2005, 08:36 AM
I read that while DSL lines are copper twisted pair lines from the DSL company (phone company?) all the way to the subscriber (and you have to be within strict short distances). I also read that cabale com[panies can combine transmission methods..."they can use fiber optics to connect neighborhoods but use copper coax wires to go from the user's home to the street.
Now what I don't understand is this. Fiber Optic cables allow very, very fast download data transmission (slowing down if the net is busy, busy.) But copper co-ax, comparatively, is much slower, right? Let's assume I get fiber optics to the street and then copper wire into my house. (I am using broadband).
Why doesn't (or 'wouldnt') the last few feet of the copper wire (say 75 feet) from the street to my house force, say, a big file (say 11 MB on up to 30-40 mb or more) to slow down tremendously, noticeably? So you only have 75 feet of a slow road but would it not take you much longer, say than the same file, coming all the way from San Francisco when you're in New England?
Can someone bring me up to speed on the answer to my question?
I'll take a guess, but I am going to say that your download would be consistently slower on a Hybrid Fiber to Co-ax run, than a straight fiber run. (that is my experience)
I have had ISDN, ADSL, and Fiber. And with each technology there is an improvement on speed, somewhere around 50-100 times faster.
The data will not go speedily and then slow down for the last half or 1/3 of the download. Instead, it goes at the speed of the slowest link in the chain. That being the run of copper from your house to the nearest Remote DSLAM. With the fiber running from the DSLAM to the equipment in the central office (CO) that is similar to the equipment used in the home except it is structured as a bank of modems. These modems, one for each home in use, along with some network and phone interfacing equipment, comprise the device known as a digital subscriber loop access multiplexer (DSLAM).
And the reason for the distance constraints lies in the copper line being used:
distance constraints are still a very real problem for small office/home offices (SOHOs) and small-to-medium enterprises (SMEs) who want DSL access. Most DSL technologies have a set distance limitation of about 17,500 feet between the customer premise and the telephone company's CO. These last mile limitations are due to poor quality, limited-bandwidth copper wire in the loop. The farther you are from the CO, the weaker the transmission. Today, it is an accepted fact that if your business is too far from the DSLAM at the "nearby" CO (Central Office), you're out of luck
http://www.arescom.com/Arescom/Arescom_2002/Other/WhitePaper_DSLAR.cfm
There's a white paper explaining it.
BUt I could be wrong. If I am let me apologize in advance.
