Comment by taftster
5 hours ago
I like your comment, but it seems the author acknowledged this as a caveat to the algorithm.
>Many home routers try to preserve the source port in external mappings. This is a property called “equal delta mapping” – it won’t work on all routers but for our algorithm we’re sacrificing coverage for simplicity.
So to what percentage is this coverage sacrificed exactly? No idea. Not as useful if the percentage is high, as you are implying.
It’s the same assumption is required for any hole punching handshake (including STUN).
> This is a property called “equal delta mapping”
FWIW I’ve worked in computer networking for 20 years and have never heard it called this. This blog is the only source that comes up when I search for that exact term. I wonder where the author got it from.
> It’s the same assumption is required for any hole punching handshake (including STUN).
This is incorrect.
Hole punching requires being able to predict external port. That's it. If the port remains the same, it certainly simplifies things, but ports going up (or down) by 1 (or 2, or 5) with each new mapping is quite common, trivial to detect and to punch through.
I wonder how many new technical terms are going to be created by LLMs - not to say that this post was N necessarily written by an LLM (but, who knows!)