Cable Forum - View Single Post - 120M How does Virgin's Fiber network work?

Eeeps · 01-01-2016, 17:23

Just looking at the downstream; for a cable modem running with eight bonded 256QAM channels it will always receive data at ~400mb/s. Unfortunately, those bits are shared amongst many modems.

Although the physical coax from the DP may not be shared, logically the data it provides is. This is why you can take your Super Hub next door (or even to the next street) and it will still work.

Coax cable (and the associated amps) have a limited bandwidth. Only about 120 channels are available on each cable segment. Unfortunately, most of these are used for TV so only about 20 are available to Broadband. This relates to about 1Gb/s of bandwidth available per cable segment. It is this limit that causes end user congestion (as it gets shared between more and more users).
If a cable segment is congested and all available channels are used, then the only fix is to physically split the segment in two (or more), thus reducing the number of users per segment.

01-01-2016, 17:23	#11
Eeeps Inactive Join Date: May 2012 Posts: 153	Re: How does Virgin's Fiber network work? Just looking at the downstream; for a cable modem running with eight bonded 256QAM channels it will always receive data at ~400mb/s. Unfortunately, those bits are shared amongst many modems. Although the physical coax from the DP may not be shared, logically the data it provides is. This is why you can take your Super Hub next door (or even to the next street) and it will still work. Coax cable (and the associated amps) have a limited bandwidth. Only about 120 channels are available on each cable segment. Unfortunately, most of these are used for TV so only about 20 are available to Broadband. This relates to about 1Gb/s of bandwidth available per cable segment. It is this limit that causes end user congestion (as it gets shared between more and more users). If a cable segment is congested and all available channels are used, then the only fix is to physically split the segment in two (or more), thus reducing the number of users per segment.