Re: [quicwg/base-drafts] eliminate the difference between when having no RTT sample and having one (#3525)

Jana Iyengar <notifications@github.com> Wed, 18 March 2020 21:43 UTC

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Subject: Re: [quicwg/base-drafts] eliminate the difference between when having no RTT sample and having one (#3525)
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janaiyengar approved this pull request.

Just a few editorial suggestions.

> +smoothed_rtt and rttvar are computed as follows, similar to {{?RFC6298}}.  When
+there are no samples for a network path:

```suggestion
smoothed_rtt and rttvar are computed as follows, similar to {{?RFC6298}}.

When there are no samples for a network path, and on the first RTT sample for
the network path:
```

> +where rtt_sample is the initial RTT.
+
+On the first RTT sample for the network path, smoothed_rtt and rttvar are set to
+the values using the formula above, using that first RTT sample as rtt_sample.
+This ensures that the first measurement erases the history of any persisted or
+default value.

```suggestion
Before any RTT samples are available, the initial RTT is used as rtt_sample. 
On the first RTT sample for the network path, that sample is used as rtt_sample.
This ensures that the first measurement erases the history of any persisted or
default values.
```

> +When no previous RTT is available, the initial RTT SHOULD be set to 333ms,
+resulting in a 1 second initial timeout as recommended in {{?RFC6298}}. Resumed
+connections over the same network SHOULD use the previous connection's final
+smoothed RTT value as the resumed connection's initial RTT.

```suggestion
Resumed
connections over the same network SHOULD use the previous connection's final
smoothed RTT value as the resumed connection's initial RTT. When no previous
RTT is available, the initial RTT SHOULD be set to 333ms, resulting in a 1 second
initial timeout, as recommended in {{?RFC6298}}.
```

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