[Rpm] [Bloat] retransmit cost over cellular

[David Lang]

what apps do you have on the phone and what are they configured to update? that 
will make a huge difference.

'idle' probably isn't nearly as passive as you think it is.

David Lang

On Mon, 18 Sep 2023, Juliusz Chroboczek via Bloat wrote:

> Hi Dave!
>
>> https://nickvsnetworking.com/mobile-ipv6-tax/
>
> « This means my Android phone consumes 4.5 MB of cellular data in an hour
>  while sitting on the desk, with 16,889 packets in/out. »
>
> So even discounting the headers, the phone receives 70 Commodore C64 worth
> of data when idle.  Every freaking hour.
>
> « We have 16,889 packets, 6,417,732 bytes in total, minus 97 bytes from
>  each gives us 1,638,233 of headers to drop (~1.6MB) giving us a total of
>  4.556 MB traffic to/from the phone itself. »
>
> The average packet size is 269 bytes.  Even if we assume that every second
> packet is a pure ACK, that's still on the order of just 500 bytes for data
> packets.
>
> Conclusions:
>
> 1. The amount of data being received is outrageous, which indicates the
>   use of JSON or XML to encode the data.  (See RFC 3252.)  (Just kidding,
>   please see RFC 8949 instead.)
>
> 2. The packet size is small, which indicates the use of a chatty REST-like
>   API rather than a streaming protocol.  The use of streaming has been
>   known since at least the 1970s, and well-documented since the 1990s.
>   For example, both IMAPv4 and Caldav can do streaming synchronisation
>   just fine.
>
> 3. The « IPv6 tax » could be reduced by 70% if the packets were reasonably
>   sized.  By 90% if the application-layer protocol were efficient enough
>   to allow delack to trigger.
>
> Conclusion of the conclusions:
>
> 4. The « IPv6 tax » is negligible when compared to the JSON/XML/REST tax.
>
> -- Juliusz
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