Subject: Re: Disabling compression by API?

Re: Disabling compression by API?

From: Daniel Stenberg <>
Date: Fri, 8 Oct 2010 22:02:40 +0200 (CEST)

On Fri, 8 Oct 2010, Aris Adamantiadis wrote:

> While compression may enhance the throughput when used with large packets
> and on slow networks, it adds latency which may not be desirable for
> interactive sessions, with a marginal benefit (ethernet frames take a fixed
> amount of bytes per packet on anyway).

Well, on a modern PC that sends a small packet compressed, is the very tiny
microsecond or whatever the compression function call takes really a factor at

I'm not saying that it does any good, I just question that it actually is
noticable. I guess if you send a large pre-compressed stream it will be
measureable at least.

> My opinion is that compression is useful when transferring files of unknown
> type, or mainly text files. Some content with high entropy (compressed
> files, video, ...) are slow to compress and decompress ; If there is an API
> call do enable/disable it (libssh does), everybody should be happy.

Right, but the question right now is mostly: what is the default?

Out of curiosity, what does libssh default to?

Received on 2010-10-08