TP-Link Deco M5 / VM SH3 / Network Switch

venger5

Standard Member
Hi,

I've recently had a speed boost under VM's Volt promotion moving from M100 to M200 and without me asking for one, VM also sent me out a SH3 (I was still using a SH2ac which had been very reliable).

Knowing the SH3 has something of a chequered past on various forums I didn't rush to plug it in but on doing speed tests over a few days it was apparent that I was getting nowhere near 200mbps (worst was 69, best about 110) with the SH2 so before I called VM I thought it best to at least try the SH3.

Night and day difference - now consistently getting above 200 with a wired connection and not far off that with wifi downstairs on the opposite side of the house (1930's three bed semi).

This has reignited my interest in getting wifi into a shed about 5m from the back of the house to hook up some wifi cameras for wildlife watching.

I'd been considering powerline adapters as a friend has assured me that even with a separate DB in the shed hanging off the main DB in the house they should still work but I've seen a few posts about mesh wifi systems and I've been looking at the Deco M5 but just want to clarify exactly the equipment chain.

If I understand it right, I put the SH3 into modem mode, I DON'T need to buy a router, I just plug the first Deco unit DIRECTLY into the SH3 (this first Deco unit will then supply the wifi for upstairs), then install another Deco unit downstairs and a third in the shed itself and essentially, they all daisy chain off each other.

Is that correct ?

I've got about four items close to the SH3 that need to be plugged in but of course in modem mode only one of the ports works on the SH3 so do I just plug a network switch into the first Deco unit hanging off the SH3 ?

Many thanks for your help.
 

mickevh

Distinguished Member
All Wi-Fi is facilitated by "Access Points" (AP's) not "routers." This is not just hair splitting over nomenclature, in the field of data networking an "AP" and a "router" are very different things. Your "get-you-on-the-Internet" omni-box just happens to contain both, and a lot more besides.

Attached to the "Using Two Routers Together" FAQ pinned in this forum is block diagram of the innards of a SOHO "router" you may find useful for comprehension. Referring to said diagram, "modem mode" turns off everything except the modem and one ethernet port. Whereas, if everything else is working then leave it alone (in router mode) and just turn off the built in Wi-Fi Access Point.

You do not need to use your router's "modem mode" to deploy an (any) alternate/additional Wi-Fi solution downstream of (any) SOHO router. Leave your router alone and if you don't want to use it's Wi-Fi, just turn the radios off - it's rarely more than a couple of clicks.

So doing will mean you can continue to use the ethernet (LAN) ports of your router, you won't have any "dual NAT" which can effect some applications and you won't endure a day of IP address carnage when you deploy your new Wi-Fi solution.

Some so-called "mesh" systems (there's no useful definition of what "mesh" means) are designed to replace your router entirely, but in your use case that is completely unnecessary. Some "mesh" systems will offer an "AP mode" (some call it "bridge mode") that means the AP's "just" function as a fleet of managed AP's. Which is what would be best for you.

If your intended system does not offer an "AP mode" then I'd choose something else that does.

It is something of an Internet Myth that to deploy an alternate/additional Wi-Fi solution you "need to put your router in modem mode" This is simply untrue. Modem mode is for fixing "other" things.

As you have illustrated, the principal reason for changing routers is because they cannot "route" the Internet traffic fast enough, not because you need to "fix" a Wi-Fi problem.
 
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venger5

Standard Member
Thanks for taking the time to post such a detailed reply.

The reason I mention modem mode is because over on the VM forums the SH3 doesn't have the greatest of reputations for a number of reasons (one of the biggest being poor wifi coverage) and pretty much everyone seems to run them in modem mode, adding their own wifi router.

My own experience of it's wifi coverage thus far is actually very good for my house and needs but it won't stretch to the shed, hence me looking at options to extend coverage out there.

Regardless of whether I keep the SH3 in router mode and disable wifi or put it into modem mode, I'll need to add a switch somewhere as I've already used up the four ports on the SH3.

Thanks again for your time.
 

mickevh

Distinguished Member
I'm afraid there's a lot of people plying (and believing) the Internet Myth that to fix "poor Wi-Fi" you need to "put your router into modem mode and buy another router." They are no doubt well meaning, but the myth stems from a poor to non-existent understanding of how the networking technology works let alone what does what and why. Fortunately, there are a few bona-fida data networking (and cabling, NAS, HDD and few other things) experts lurking in this forum, so I'd commend anyone to favour the advice here rather than a bunch of "lay people" talking to each other in a user forum about things none of them understand.

When folks leap straight for the "modem mode" - er - "fix" for Wi-Fi issues, it's a real red flag that their understanding is poor.

There's no problem adding extra ethernet switch(es.) Basic SOHO models are cheap as chips these days. Don't forget to factor in the switch-router "uplink" when contemplating how many ports you need to avail - it's easy to forget it. If you look for a "mesh" system you might find some that also include a few extra ethernet ports in each node whereby a node effectively functions as an AP/switch combo which could be useful. However, I advise to never "just assume" any item of hardware can function in any given way - always check the datasheets and presume that feature "X" is not present unless it is explicitly cited that it is (or pre-sales support will authoritatively state so.) Downloading and reading the User Guide of a prospective purchase is often revealing - a lot of vendors offer them online.
 

venger5

Standard Member
Thanks for coming back again, much appreciated.

Could I just clarify what you mean regarding switch - router uplink?

Is it just simply being aware that you'll lose the use of one of your ethernet ports on the switch as it will be needed to connect the switch to the router or is it something more complicated than that?
 

mickevh

Distinguished Member
Could I just clarify what you mean regarding switch - router uplink?

Is it just simply being aware that you'll lose the use of one of your ethernet ports on the switch as it will be needed to connect the switch to the router or is it something more complicated than that?

Exactly that. I've seen it happen where calculations were done on "how man ports we need" and people forgot to factor in the interlink(s.)

In choosing a switch, if you have a choice between 10/100mbps and 10/100/1000mbps (AKA "gigabit.") I would choose the latter even if you do not have any gigabit devices yet - the price difference is minimal. Though at time of writing, I suspect "10/100" only is becoming a rarity, but it's something to look out for especially if you find a "bargain."
 
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