rebus9
join:2002-03-26
Tampa Bay Reviews:
 ·Verizon FiOS
 ·Bright House
| reply to DataRiker
Re: I don't get it.... said by DataRiker:Fiber has a latency advantage?
Other than a small advantage during encoding/decoding, both mediums travel at the same speed.
Yes, FTTP has a latency advantage over HFC. It's not much, typically less than 10ms. The extra HFC latency is introduced at the headend and local plant during the media conversions that take place. But it exists and is measurable. Once beyond the local plant, both carriers use fiber for core, regional, and longhaul.
But clearly, I downplayed the significance of it in my previous post. I don't think there is a real-world difference to the end user as long as the provider actually delivers the full 300/65.....
.... except perhaps for extreme gamers where a few milliseconds can mean the difference between winning and losing. |
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| I mentioned the encoding/decoding advantage, but its about ~1ms or 2ms.
Insignificant really. |
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rebus9
join:2002-03-26
Tampa Bay Reviews:
·Verizon FiOS
·Bright House
| I have both HFC and FIOS, and the difference is a solid 8-10ms.
This is quite easy to test. I have servers colocated in Tampa, in a facility who has 5 transit carriers-- one of them being Brighthouse. The colo is located in 400 N Tampa St, which is also where one of Brighthouse's downtown POPs is located. To make it even better, the BHN-owned router that terminates the fiber into this facility is (literally) 6 cabinets down the row from our cabinet. My pings across BHN Road Runner to these servers homed on BHN Enterprise Fiber, are 14-16ms.
I'm familiar with the fiber path between our part of the county into Hillsborough county. I can't tell you street by street, but I do know the general path, and which areas of the city it crosses before reaching downtown Tampa. It's reasonably direct, with some obvious twists and turns as would be any metro-regional path.
Next up is FIOS. We have offices connected via FIOS, which are even further away-- on the order of 20+ miles further. Ping times across FIOS, to these other hosts on FIOS, are in the 6-8ms range.
Now, let's forget hosts for a moment and talk routers. Ping times across a Brighthouse Road Runner connection to Brighthouse routers known to be in Tampa are on the order of 12-14ms. Ping times to Verizon routers known also to be in Tampa, are 4-6ms.
No matter how you approach it, across approximately the SAME physical path distance, the HFC network induces approximately 8-10ms of additional latency. |
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4 edits | There is no possible way that 2 different ISP's used the same route and equipment to a remote location.
The extra latency over copper is due to the encoding used to mitigate line noise and such.
On Fast path DSL you wont lag more than about 1.5ms or so given an equal fiber run. |
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rebus9
join:2002-03-26
Tampa Bay Reviews:
·Verizon FiOS
·Bright House
| said by DataRiker: There is no possible way that 2 different ISP's used the same route and equipment to a remote location. You clearly didn't read the post. I never said they used the same routes.
What I DID say is the physical paths are of comparable distance. |
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3 edits | To compare latency you would have to take the same route on comparable equipment.
The vast majority of the lag you see is certainly in either the Route or an overloaded or old piece of equipment (Router, CMTS, whatever...) |
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BiggA
join:2005-11-23
EARTH | reply to rebus9
Those are insanely low. However, 10ms difference in latency is absolutely nothing, even to the more hardcore gamer. |
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