RE: Practical guide to predicting latency effects?
My data point: I'm working from home. My computer is connected through company VPN, over wifi to Comcast. Comcast speed test says 18mS. I use VNC and Webex with voice and video through the computer. VNC response time and voice delay is not noticeable. Regards, Jakob. -----Original Message----- Date: Tue, 7 Apr 2020 22:52:18 +0000 From: Adam Thompson <athompson@merlin.mb.ca> I’m looking for a practical guide – i.e. specifically NOT an academic paper, thanks anyway – to predicting the effect of increased (or decreased) latency on my user’s applications. Specifically, I want to estimate how much improvement there will be in {bandwidth, application XYZ responsiveness, protocol ABC goodput, whatever} if I decrease the RTT between the user and the server by 10msec, or by 20msec, or by 40msec. My googling has come up with lots of research articles discussing theoretical frameworks for figuring this out, but nothing concrete in terms of a calculator or even a rule-of-thumb. Ultimately, this goes into MY calculator – we have the usual north-american duopoly on last-mile consumer internet here; I’m connected directly to only one of the two. There’s a cost $X to improve connectivity so I’m peered with both, how do I tell if it will be worthwhile? Anyone got anything at all that might help me? Thanks in advance, -Adam Adam Thompson Consultant, Infrastructure Services [[MERLIN LOGO]]<https://www.merlin.mb.ca/> 100 - 135 Innovation Drive Winnipeg, MB, R3T 6A8 (204) 977-6824 or 1-800-430-6404 (MB only) athompson@merlin.mb.ca<mailto:athompson@merlin.mb.ca> www.merlin.mb.ca<http://www.merlin.mb.ca/>
The only informal paper I remember is Stuart Cheshire’s It’s the latency, stupid… http://www.stuartcheshire.org/rants/Latency.html <http://www.stuartcheshire.org/rants/Latency.html> Given it’s from the dialup days, but latency is still the same just a lot lower. I would thing I would recommend now is checking out SRE docs as well for application latency it's not network related, but does affect performance. https://landing.google.com/sre/sre-book/toc/ <https://landing.google.com/sre/sre-book/toc/> Sincerely, Eric Tykwinski TrueNet, Inc. P: 610-429-8300
On Apr 8, 2020, at 6:36 PM, Jakob Heitz (jheitz) via NANOG <nanog@nanog.org> wrote:
My data point:
I'm working from home. My computer is connected through company VPN, over wifi to Comcast. Comcast speed test says 18mS. I use VNC and Webex with voice and video through the computer. VNC response time and voice delay is not noticeable.
Regards, Jakob.
-----Original Message----- Date: Tue, 7 Apr 2020 22:52:18 +0000 From: Adam Thompson <athompson@merlin.mb.ca>
I’m looking for a practical guide – i.e. specifically NOT an academic paper, thanks anyway – to predicting the effect of increased (or decreased) latency on my user’s applications.
Specifically, I want to estimate how much improvement there will be in {bandwidth, application XYZ responsiveness, protocol ABC goodput, whatever} if I decrease the RTT between the user and the server by 10msec, or by 20msec, or by 40msec.
My googling has come up with lots of research articles discussing theoretical frameworks for figuring this out, but nothing concrete in terms of a calculator or even a rule-of-thumb.
Ultimately, this goes into MY calculator – we have the usual north-american duopoly on last-mile consumer internet here; I’m connected directly to only one of the two. There’s a cost $X to improve connectivity so I’m peered with both, how do I tell if it will be worthwhile?
Anyone got anything at all that might help me?
Thanks in advance, -Adam
Adam Thompson Consultant, Infrastructure Services [[MERLIN LOGO]]<https://www.merlin.mb.ca/> 100 - 135 Innovation Drive Winnipeg, MB, R3T 6A8 (204) 977-6824 or 1-800-430-6404 (MB only) athompson@merlin.mb.ca<mailto:athompson@merlin.mb.ca> www.merlin.mb.ca<http://www.merlin.mb.ca/>
participants (2)
-
Eric Tykwinski -
Jakob Heitz (jheitz)