[portillo]

That is not the round trip time, it's the one-way delay. Also, processing time can be significant in satellite networks. Finally, given the current architecture of SpaceX without crosslinks, the total RTT will be ~30 ms + processing time + whatever is the RTT of the backbone network they deliver the traffic to.

[shaklee3]

I think the processing time might be heavily driven by the waveform and how they do the networking. As complexity increases and they move towards a software defined networking schema, the latency goes up. If they're not using ready-made/proven ASICs, the latency goes up. I don't believe any of this is public from them.

[portillo]

I think so too. In addition, they seem to have regenerative payloads on-board (otherwise I don't get how they get ~20Gbps/sat with a single Ka-band antenna), so they need to do full decoding + encoding on the satellite. Not sure how fast that can be done, but it will add some latency ms probably.

[shaklee3]

This is the first I've heard someone speculate about that. I didn't think they were doing 20G with a single antenna, but that they were adding all spectrum together that it's capable of processing (even if it doesn't get access to it all). On-board processing would also require a significant amount of power, and it's riskier.