Number of Wi-Fi connections on hAP mini

RouterOS Wireless Networking
1

I’m always on the look out for a cost-effective Wi-Fi 4 router/access point for small cafe installations and I came across the hAP mini at Broadbandbuyer. Lovely looking device. I normally install TP-LINK TL-WA801ND but these aren’t the best devices IMO :wink: Specifically they struggle with stable DHCP and, more importantly, a limited number of maximum concurrent connections.

How many Wi-Fi connections can the hAP mini handle? In the cafe situation, there are lots of users coming and going - bandwidth isn’t a big issue but lots of low-speed connections is.

Side question - it has internal antenna; does this make a big difference to range compared to external antenna?

Thanks, Rob.

2

The main limitation of the hAP mini is its RAM, a bit in the small side with only 32M RAM, which brings one problem that you can search for in the forum: often it is difficult to upgrade, as the upgrade firmware is downloaded in RAM, and depending on your configuration it can get tricky.

I have good experience with Mikrotik and I like how RouterOS can handle and script very flexibly quite different devices with basically the same source code. But I have never got this model, all my devices have 64M or 128M. By default RouterOS configures a dhcp lease time of 10m, which is good for a cafe that sees lots of devices passing by (notice that modern android phones connect to every open AP they see…). By default, in Router OS ESTABLISHED tcp connections have a timeout of 24 hours, I see lots of stale connections from phones that went to sleep. You could easily change both parameters.

I would recommend trying one with a simple configuration in your use case. Also you could consider the mAP lite (just one eth port) or hAP ac lite (5 eth, dual 2.4-5MHz, USB, more expensive), both 64M RAM. Notice also that those devices are MIPS. While they can handle VPNs, don’t try to get them pushing a lot of encrypted traffic through them…

3

Nostomog, could you tell us why “MIPS” is not good to handle encrypted traffic?

What about https, which is everywhere nowadays?

4

It is not a problem of handling encrypted traffic, but of doing encryption. the MIPS CPU has only one core, and does not have hardware support for AES encryption.

So, if you are terminating encrypted VPNs in your router, the CPU will limit how much bandwidth it can move. See for example that even a 4 core ARM chip with hw support for encryption can’t handle the whole bandwidth while encrypting : https://mikrotik.com/product/hap_ac2#fndtn-testresults
We have no data for MIPS chips, but they are definitely less capable.

https is not encrpyted in the router, so the router is not doing any CPU-intensive task when routing it.

5

Your initial post tells me all I need to know. You install crappy TP Link wifi routers in small cafes and this is how you treat your customers LOL.
Suggest you install the RB4011 from now on and give your customers (and their clients) a decent product! :wink:

6

You install crappy TP Link wifi routers in small cafes and this is how you treat your customers LOL.

I think you’ll find the reason was also in my first sentence: cost-effective solution. Sure, the 4011iGS looks like a fine device but it’s well over £200 compared to £25. And the only problem with the TP-Link is that it struggles with a lot of connections and doesn’t release connections quickly enough. Former is probably hardware limitation and the later is software. Putting in a device with 10 x 1Gbps ports (of which none will be used) and Wi-Fi 5 when the internet connection is still 10Mbps ADSL-2 is overkill and I don’t like overcharging my customers.

So hence the reason I was interested in the hAP range. MikroTik are not that well known in the UK but I was interested when I saw them on Broadbandbuyer. It sounds like the mini is a little under powered but I punted out the £20 and bought one anyway. I’ve on good terms with the cafe I was talking about, it’s 200m from my office so I’m going to plug it in and give it a go for a week. But the hAP sounds a more suitable device with 64MB of RAM.

Out of interest, what kind of things take up RAM in a router? My knowledge of networking overall is pretty good but I’ve never dug in deep to what actually goes on inside. The operating system will obviously need RAM for it’s own variable storage. I infer that there is a “Per connection” overhead, i.e. the router OS allocates a certain amount of RAM for each connection? As a sometimes (games) programmer, I’m thinking about how a router OS works.

7

hAP ac^2 is very much in the same price range as hAP and offers 5MHz radio too.

If the mini works for you I think it is quite ok. As a bonus it draws very little electric power (3.5 W).

You have, in order of relevance for your intended use:

  • Connection tracking for NAT/firewall
  • IP/IPv6 route cache (the system assigns max sizes depending on RAM)
  • DNS cache ( " )
  • standing DHCP leases
  • firewall rules, which are not a problem unless you use things like blacklisting or similar that involve address lists.
  • wireless registration-table (connections). Those are purged quickly
  • If you are using traffic shaping, queues take RAM
  • If you are using PPP-based VPNs, the user list goes on RAM, and of course dynamic interfaces…
  • If you are using IPsec, identities and standing associations
  • Of course, once you start going OSPF, BGP… there are more things that take RAM

For a bar I would say none of these are going to bite you if you use a short DHCP lease duration. Default is 10m, quite reasonable. For connection tracking, the “tcp-established-timeout: 1d” is a bit too generous, I often see stale connections from phones that went to sleep. If you start to have upstream flapping problems the established TCP connections remain there for about 1 day. I have just now 25 stale connections (of ~100) in my home router with only a couple of phones and laptops. Those come from sleeping/waking up several times yesterday

Some traffic queueing might come handy to ensure bandwidth sharing is fair, specially if the connection becomes saturated, but I’d only look there after checking how it works in practice.

8

hAP ac^2 is very much in the same price range as hAP and offers 5MHz radio too.

It was looking for AC access points that brought me to the Mikrotik range. Whilst the Wi-Fi 4 devices are competitively priced here in the UK, the Wi-Fi 5 (AC) variants are middle of the pack. For example the TP-Link Archer A5 is £29 compared to £43 for the hAP AC lite. But of course, the hAPs are far more configurable. And as I came here looking for alternatives to the flaky TP-Link, I would be mad to consider the TP-Link again :slight_smile:

Broadband buyer struggles with categorising the hAP range - sometimes they are under access points and sometimes under routers. They should probably be categorised as both but I suspect BBB software can’t handle that.

You have, in order of relevance for your intended use:

Thanks for that, interesting reading.

For a bar I would say none of these are going to bite you if you use a short DHCP lease duration. Default is 10m, quite reasonable.

I did notice that as the default on the hAP and wondered why quite so low. First time I’ve seen a default anywhere near that low - often 24 hours. But for a cafe environment, yes a short DHCP lease is preferable. I’ve never been brave enough to go down to 10 mins - usually set an hour.

For connection tracking, the “tcp-established-timeout: 1d” is a bit too generous, I often see stale connections from phones that went to sleep.

This, I suspect, is the problem that hits the TP-Link - it hangs onto connections too long,

Some traffic queueing might come handy to ensure bandwidth sharing is fair, specially if the connection becomes saturated, but I’d only look there after checking how it works in practice.

I didn’t look at Mikrotik for this aspect but I’m pleased it’s there as I have another client where this will be very useful.

Thanks, Rob.

9

Side question - it has internal antenna; does this make a big difference to range compared to external antenna?

Answering this question with some unscientific tests but the hAP mini does as well as any other similar device range wise.