Has any ISP or regulatory body set a standard for latency necessary
to support interactive uses?
It seems to me that a 2+ second delay is way too high, and even if
it happens only occasionally, users may set up their systems to
assume it may happen and compensate for it by ading their own
buffering at the endpoints and thereby reduce embarassing glitches.
Maybe this explains those long awkward pauses you commonly see when
TV interviewers are trying to have a conversation with someone at a
remote site via Zoom, Skype, et al.
In the early Internet days we assumed there would be a need for
multiple types of service, such as a "bulk transfer" and
"interactive", similar to analogs in the non-electronic transport
systems (e.g., Air Freight versus Container Ship). The "Type Of
Service" field was put in the IP header as a placeholder for such
mechanisms to be added to networks in the future,
Of course if network capacity is truly unlimited there would be no
need now to provide different types of service. But these latency
numbers suggest that users' traffic demands are still sometimes
exceeding network capacities. Some of the network traffic is
associated with interactive uses, and other traffic is doing tasks
such as backups to some cloud. Treating them uniformly seems like
bad engineering as well as bad policy.
I'm still not sure whether or not "network neutrality" regulations
would preclude offering different types of service, if the technical
mechanisms even implement such functionality.
Jack
On 2/27/24 14:00, rjmcmahon via Nnagain
wrote:
Interesting blog post on the latency part
at
https://broadbandbreakfast.com/untitled-12/.
Looking at the FCC draft report, page 73, Figure 24 – I find it
sort
of ridiculous that the table describes things as “Low Latency
Service” available or not. That is because they seem to really
misunderstand the notion of working latency. The table instead
seems
to classify any network with idle latency <100 ms to be low
latency
– which as Dave and others close to bufferbloat know is silly.
Lots
of these networks that are in this report classified as low
latency
would in fact have working latencies of 100s to 1,000s of
milliseconds
– far from low latency.
I looked at FCC MBA platform data from the last 6 months and
here are
the latency under load stats, 99th percentile for a selection of
ten
ISPs:
ISP A 2470 ms
ISP B 2296 ms
ISP C 2281 ms
ISP D 2203 ms
ISP E 2070 ms
ISP F 1716 ms
ISP G 1468 ms
ISP H 965 ms
ISP I 909 ms
ISP J 896 ms
Jason
It does seem like there is a lot of confusion around idle latency
vs working latency. Another common error is to conflate round trip
time as two "one way delays." OWD & RTT are different metrics
and both have utility. (all of this, including working-loads, is
supported in iperf 2 -
https://iperf2.sourceforge.io/iperf-manpage.html - so there is
free tooling out there that can help.)
Bob
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