Low speed on rsync ssh transfer

I am observing slowness in a transfer between 2 WD My Cloud EX4100.

NAS Destination fw version 2.31.149
NAS origin fw version 2.11.178
Command executed in nas origin:
nohup rsync -rave ssh --delete / mnt / HD / HD_a2 / Public / NOC / root@X.X.X.X: / mnt / HD / HD_a2 / NOC / repo-01 / ststorage07 /> r
Attached screenshot of the network activity of one of the devices
If this topic is repeated, I apologize and thank you if you pass the link to the solution or the correct way to do it.
The bad English is due to google translator, apologize.
Thank you.