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Will Fiber-To-the-Home Create a New Digital Divide?

Posted by samzenpus on from the have-and-have-nots dept.

First time accepted submitter dkatana writes Having some type of fiber or high-speed cable connectivity is normal for many of us, but in most developing countries of the world and many areas of Europe, the US, and other developed countries, access to "super-fast" broadband networks is still a dream. This is creating another "digital divide." Not having the virtually unlimited bandwidth of all-fiber networks means that, for these populations, many activities are simply not possible. For example, broadband provided over all-fiber networks brings education, healthcare, and other social goods into the home through immersive, innovative applications and services that are impossible without it. Alternatives to fiber, such as cable (DOCSYS 3.0), are not enough, and they could be more expensive in the long run. The maximum speed a DOCSYS modem can achieve is 171/122 Mbit/s (using four channels), just a fraction the 273 Gbit/s (per channel) already reached on fiber.

2 of 291 comments (clear)

  1. Re:No. by Bengie · · Score: 5, Informative

    TCP_WINDOWS_SIZE can grow up to 2GB which is enough for a 10GB link with 1600ms latency. I'm not going to say that your OS will be happy about it, but that's the logical limit. As for AES 256 encryption, a modern desktop CPU can handle 100mb-300mb per core, unless you have AES-NI, then it's more like 1gb per core. OR if you're like me, you NIC supports line rate IPSEC offloading, so 4gb/s with 0% cpu overhead, assuming IPSEC and not VPN.

  2. Re:No. by JMJimmy · · Score: 5, Informative

    1) TCP alternatives are already being developed
    2) TCP_WINDOW_SIZE problem was solved long long ago with TCP_WINDOW_SCALING. The limit is roughly 100 Gbit/s at 80ms
    3) Not sure where you're getting your data from but reality is a very different place from where you live. 25 MBps would be an Intel Atom 230 decrypting AES-128-CBC. 5 year old mobile/low power processors were never meant to stand the test of time. Take something from around the same period, like say an Intel T5550 and all the sudden you're up to 80MBps for AES-256-CBC (or 109MBps AES-128-CBC). Even dropping down to a P4 you can get 75MBps for AES-256-CBC.

    Also, arc_four (aka RC4) is not even worth discussing as it's completely useless as encryption. RC6 is (comparatively) fast at low byte counts on specific platforms but quickly plateau with little performance increase after 128 bytes and slows by a factor of 3 if the hardware is not optimal. Rijndael, which was chosen for AES, had consistently fast speeds no matter the bytes or platform. The reality is that any chip with the AES-NI instruction set makes it a moot point, by example the i7-3960X is churning out 5.7GBps. Without it, performance does suffer, but you're still talking 250-400Mbps on a 4 core chip.

    The real question is how the heck this got posted to Slashdot. DOCSIS 3.1 bumps the limits to 10 Gbit/s down, 1 Gbit/s up and even on DOCSIS 3.0 - who says you've got to be stuck at 4 channels? 24 Channel is already actively deployed in Canada at 200-250Mbps down/15-30Mbps up, 1.5Gbps/150Mbps in the UK.