I have it connected to a billion 8800NL in full bridge mode, prevents having to drop the line potentially causing DLM kicking in when the synology needs a reboot, not that I really need to reboot it except when new firmware comes out, its rock solid for me.
You would need a separate modem unless the HH5 can be put in bridge modem only mode.
I dont have one im afraid so cant help there.
I also have a Synology NAS, a old one now - 1513+ and later added the 5 disk expansion model DX513 - never looked back, its a major investment but the things you can with them are great.
Edited by Rolandrat (Tue 19-Apr-16 14:14:35)