There are several factors in this master browser "workgroup" game. This is a parity system, where all systems in the workgroup can and should participate - and not only the NAS. The original idea of having the "os level" on 20 ensures, the typically lower power NAS not taking the priority over the other systems (typically Windows, and potentially more advanced, due to the fact the SAMBA team has to re-engineer newly invented Microsoft features, mostly in a recative way.
The first thing we might want to have in the LAN (respective the workgroup) is _one_ master browser.
Please go to the "Advanced Options" tab of Home>> Network Services>> Microsoft Networking and enable "Local Master Browser"
In general, I tend to say this should be enough to get the NAS "browsabe". When you have multiple NAS, you can (and likely should) enable more than one as a local master browser, this should not hurt.
Digging somewhat deeper also unveils the "preferred master" and the "os level" parameters, which are related. With "preferred master" set to yes, on joining the network, the preferred master (only one can be active on the net at a time) calls an election. The "os level" is used as a number of votes - the one with the higher will win. With the default setting on 20, the QNAP NAS will let any Windows machine able to be a preferred master to win, historically this was done to not over-vote an existing Windows NT server on the network, nor an actual Windows system. It does not require a lot of fantasy, that some tight security settings or third party firewalls on the Windows systems might block this capability, leaving the net un-browsable.
By rule of thumb, an "os level" around 35 would over-vote the other Windows machines on the network; setting it higher should be required for now legacy Windows network environments (pre-AD) only, to ensure a specific typically big server becomes _the_ master in the LAN.
Potentially, QNAP should add some more advanced configuration options for
- preferred master
- os level
This should keep everyone happy then, and will ensure to leave the adjustment of these parameters to the user to gain a browsable network. Hope this gives some insight.
After all the years, I don't have the full picture. We don't run WINS on our networks, just DNS (either standalone BIND or Active directory integrated), and have the "Local Master Browser" enabled on the NAS. Like this, all Windows, OS X and Linux clients are able to discover it by browsing - before and after v3.3.x firmware. Not sure if there is a changed default, requiring to enable explicitly the "local browser".