Protocol 1 is the original burp protocol.
All versions of burp support it, and it is stable.
If you are using burp-2.0.x, make sure that you set protocol=1 in your
burp-server.conf, or you may unintentionally be using protocol 2 for
Protocol 1 operates at file-level granularity. If a file's timestamps have not
changed since the previous backup, it will not copy that file across the
If the file needs to be backed up again, it will (optionally) use librsync in
order to save network traffic. The server will send the client a librsync
signature of the previously backed up file. The client will use the signature
to send back only the changes, and the server will assemble the new file by
using the previous file plus the changes.
If the file needs to be backed up again and librsync is disabled, the client
will just send the entire file.
On the server side, a client's backups are stored in directories independent of
the storage directories of other clients. The storage directories resemble
'hard link farms'.