Re: [iot-wg] CoAP and CGN

[Roger Light <roger@xxxxxxxxxx>]

On Mon, Nov 30, 2015 at 8:30 AM, Julien Vermillard
<jvermillard@xxxxxxxxx> wrote:

> In practice the device communicates regularly with the server (for example:
> every 15 min to once a week) or when some data are ready to send.
> For that CoAP beat MQTT in byte consumption because DTLS PSK both way
> handshake is ~800 bytes where a usual TLS/TCP handshake is 4k~6k and
> piggybacked ack save also few more bytes over TCP ACKs.

For completeness, I just used wireshark to grab packets when
connecting with a mosquitto_sub that had been nobbled not to send any
real data to a mosquitto instance listening with TLS-PSK  over TCP.
The total on the wire byte count was 1419.

Cheers,

Roger