User-Agent:       Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
Firefox/52.0
Build Identifier: 

Using compression when doing an rsync between a system with rsync 3.1.1 or
newer (as is used on Tumbleweed now) and a system with an older rsync version
no longer works. The workaround is to compile rsync with
"--with-included-zlib=yes"

Reproducible: Always

Steps to Reproduce:
1. When using rsync with the -z option you'll get a message telling you to use
-zz and compression will be disabled.
2. When using rsync with the -zz option you'll get an error from the remote
server as it doesn't understand this option.
3.
Actual Results:  
Only uncompressed rsync is possible.

Expected Results:  
You should be able to use compression when talking to an older system.

There are already numerous threads on this problem on the web. One good example
with lots of details and other links is

https://bugs.mageia.org/show_bug.cgi?id=13669