How the Internet works: Submarine fiber, brains in jars, and coaxial cables | Ars Technica
But how does Interner work? Take a deep dive into Internet infrastructure and visit to a subsea cable landing site. This article is simply not talking about the wonders of TCP/IP or pervasive Wi-Fi hotspots, though those are vitally important as well. No, we’re talking about the big infrastructure: the huge submarine cables, the vast landing sites and data centres with their massively redundant power systems, and the elephantine, labyrinthine last-mile networks that actually hook billions of us to the Internet.
Wide Web is a global network. Providing an Internet service goes beyond the mere capabilities of a single ISP on this sceptred isle or, indeed, the capabilities of any single ISP anywhere in the world.
Subsea cables are very important – they are are fiber optic cables. The nearer to the surface you get, the more protection—armour—you need. At depths of seas the cable diameter can be just 17mm. The construction of core of a submarine cable: the fibre-optic pairs protected by steel, the copper sheath for power delivery, and a thick polyethylene insulating layer. Repeaters—effectively signal amplifiers—are required to boost the light transmission over the length of the fibre optic cable (one of these transatlantic subsea cables has 148 amplifiers powered by about 4,500V each end (4,100V at around 600mA for the Atlantic PFE), designed to be maintenance-free for 25 years, ).One of the main issues affecting this application of photonics communications is the optical dispersion of the fibre. There are clients who will buy a 100G direct link but not that many. A lower-tier ISP, for example, wanting to buy transmission capability from us, will opt for a 10G circuit.
With MPLS we can provide any BIA [burned in address] or Internet—any services you like depending on what the customers want: It provides IP, Internet, and point-to-point services to our customers.
The layout in the NOC (network operations centre) area of the site is much the same as you’d find in any office.
If the monitoring detects anything unusual, it can proactively deal with an intrusion and reroute the traffic via a different firewall, which can filter out any intrusion. That’s proactive DDoS mitigation. We monitor it from here using PRTG software so we can check the status of the KPIs [key performance indicators].
Openreach bring DOCSIS and VDSL2 respectively to an increasing number of homes and businesses. It’s also worth mentioning that DOCSIS 3.0 is the leading last-mile network tech over in the US, with about 55 million out of 90 million fixed-line broadband connections using coaxial cable. ADSL is in second place with about 20 million and then FTTP with about 10 million. Hard numbers for VDSL2 deployment in the US are hard to come by.
DOCSIS 3 that will allow cable ISPs to offer downstream connection speeds of 400, 500, or 600Mbps as needed—and then after that there’ll be DOCSIS 3.1 waiting (10Gbps is possible downstream and eventually 1Gbps upstream).
FTTC and DOCSIS look set to dominate the wired UK consumer Internet access market. Wi-Fi is mostly an extension of existing FTTC and DOCSIS Internet access.
Virgin’s current deployment of FTTH uses RFOG (radio frequency over glass) so that standard coaxial routers and TiVo can be used, but having an extensive FTTH footprint in the UK would give the company a few more options in the future as customer bandwidth demands increase.