5 ms·

> By contrast, fiber is symmetric, offering full capacities up and down at once. So while cable has a technical justification for "service levels" to offer a se

by jauer 13y ago

> By contrast, fiber is symmetric, offering full capacities up and down at once. So while cable has a technical justification for "service levels" to offer a server, fiber providers do not. Google Fiber is 1000/1000 Mbit/s symmetrical. Link symmetry is a property of the datalink protocol and service provisioning, not the physical media. Many, if not most, FTTH deployments use PON which delivers asymmetric bandwidth that is shared among a number of users. GPON delivers 2.488Gbps down and 1.244Gbps up and is typically shared between 16 and 64 users.

voltagex_ 13y ago
Crap, the Australian NBN is going to be GPON. It's going to be DOCSIS2 all over again - good until you get a lot of users in your neighborhood.
Terretta 13y ago
For some reason, I was under the impression Google's FTTH (fiber to the home) was using real (active) fiber networking home runs instead of telco/cable's bastardized passive optical splitting down and TDM up. Wiki cited 1000/1000 symmetric, so I assumed they were using active symmetric. Seems to be some debate about it: http://www.dslreports.com/forum/r27731107-Google-Fiber-Latest-Installs-Suggest-Non-PON-Tech http://www.dslreports.com/forum/r27731107-Google-Fiber-Lates... If it's not real fiber networking, then yeah, same asymmetric song and dance as cable. But see pages 10 and 11 of this Google PDF explaining why they might as well use symmetric point to point: http://static.googleusercontent.com/external_content/untrusted_dlcp/research.google.com/en/us/pubs/archive/36936.pdf http://static.googleusercontent.com/external_content/untrust... It says end run to users is the ultimate future proof approach and a costs negligible amount more. If they didn't go that way, well, I am disappointed.
- jauer 13y ago
  It is also possible that they are using WDM-PON with a different wavelength for each subscriber. Even with Active Ethernet (the industry term for dedicated run of fiber to each subscriber) you likely still have a bandwidth constraint somewhere, be it at the switch uplinks or border routers so some level of oversubscription is a given. Right now FTTH networks are getting away with some pretty wild oversubscription ratios since content and consumption are lagging. From what I've seen on my network residential traffic tends to interleave pretty well as it is really bursty. Business traffic tends to a constant during the work day so can't interleave as many business customers. It will be interesting to see what Google Fiber charges medium & large businesses.
  - Terretta 13y ago
    Just checked your profile -- love what you're doing. I helped start up a metro ISP in early 90s that we grew gangbusters by guaranteeing no busies and max modem speeds, till it got rolled up by a telco in late 90s. Incidentally, as this is about hosting one's own servers, early on I wrote the first (as far as I know) dynamic DNS for dial-up users, so when you connected to a Portmaster and auth'd via RADIUS, your username.isp.com got pointed to your dynamic IP, allowing you to host over dialup under your own name. Customers even ran their own mail servers at home since SMTP was happy to wait for them to dial in. I believed in user publishing then and still do today. From day one competitor telco ISP services (and telco backbone links) were so oversubscribed it felt immoral. Sorry to hear that's still not changing.

by jauer 13y ago

voltagex_ 13y ago

Crap, the Australian NBN is going to be GPON. It's going to be DOCSIS2 all over again - good until you get a lot of users in your neighborhood.

Terretta 13y ago

For some reason, I was under the impression Google's FTTH (fiber to the home) was using real (active) fiber networking home runs instead of telco/cable's bastardized passive optical splitting down and TDM up. Wiki cited 1000/1000 symmetric, so I assumed they were using active symmetric. Seems to be some debate about it: http://www.dslreports.com/forum/r27731107-Google-Fiber-Latest-Installs-Suggest-Non-PON-Tech http://www.dslreports.com/forum/r27731107-Google-Fiber-Lates... If it's not real fiber networking, then yeah, same asymmetric song and dance as cable. But see pages 10 and 11 of this Google PDF explaining why they might as well use symmetric point to point: http://static.googleusercontent.com/external_content/untrusted_dlcp/research.google.com/en/us/pubs/archive/36936.pdf http://static.googleusercontent.com/external_content/untrust... It says end run to users is the ultimate future proof approach and a costs negligible amount more. If they didn't go that way, well, I am disappointed.

jauer 13y ago
It is also possible that they are using WDM-PON with a different wavelength for each subscriber. Even with Active Ethernet (the industry term for dedicated run of fiber to each subscriber) you likely still have a bandwidth constraint somewhere, be it at the switch uplinks or border routers so some level of oversubscription is a given. Right now FTTH networks are getting away with some pretty wild oversubscription ratios since content and consumption are lagging. From what I've seen on my network residential traffic tends to interleave pretty well as it is really bursty. Business traffic tends to a constant during the work day so can't interleave as many business customers. It will be interesting to see what Google Fiber charges medium & large businesses.
- Terretta 13y ago
  Just checked your profile -- love what you're doing. I helped start up a metro ISP in early 90s that we grew gangbusters by guaranteeing no busies and max modem speeds, till it got rolled up by a telco in late 90s. Incidentally, as this is about hosting one's own servers, early on I wrote the first (as far as I know) dynamic DNS for dial-up users, so when you connected to a Portmaster and auth'd via RADIUS, your username.isp.com got pointed to your dynamic IP, allowing you to host over dialup under your own name. Customers even ran their own mail servers at home since SMTP was happy to wait for them to dial in. I believed in user publishing then and still do today. From day one competitor telco ISP services (and telco backbone links) were so oversubscribed it felt immoral. Sorry to hear that's still not changing.