Hi all, I'm looking to buy a new Wi-Fi router to run OpenWrt with the Travelmate package. I have looked through the Travelmate support thread but couldn't really find any device recommendations. Same for the Supported Devices page, or more specifically the Buyer's Guide.
Can anyone point to devices known to play well with Travelmate? In general terms, I'm looking for a reasonably recent Wi-Fi router with at least two non-WAN Ethernet ports.
I'm not aware of any devices for which Travelmate won't work, aside from very low-end wifi devices such as the Raspberry Pi.
The most significant feature of Travelmate is to gracefully handle the situation where the expected upstream SSID is not available, specifically on single radio devices. In this situation (on a single radio device) the wifi AP cannot start because the channel selection is dictated by the upstream AP (that is not there). Travelmate solves this issue by turning off the STA connection after a timeout period when this happens, thus allowing the AP mode to start.
To be clear, travelmate has lots of other features, too, but I'm pretty sure that the one mentioned above was what prompted the development in the first place.
So with that said, any modern purpose-built travel router that is supported by OpenWrt in general will work with travelmate. The GL-inet MT3000 is well regarded (although it only has 2 ethernet ports; nominally one for wan and one for lan although you could certainly reassign them).
Avoid devices like the Raspbery Pi (all generations) since they have very low end wifi chipsets that do not support simultaneous dual band operation and also don't support simultaneous STA + AP modes.
All of them ?
Dual radio is probably preferred though.
If you like the MT3000, have a look at the Cudy TR3000, same everything but the flash, it's half the size of the MTs.
I already asked the question somewhere else but i did not yet get a reply so far, so I will retry here :).
When you say AP mode what exactly do you mean. Is it serving as a router/wifi bridge at that point so devices connected to it can talk to each other, even though they have no internet access ?
I would assume so otherwise there seems to be little use in being an AP, but I am very confused by the usage of the word AP then (and in the documentation) as for me an AP is not a router/wifi bridge and needs an external router to be useful.
When you setup a wifi network, your router will broadcast an SSID for your client devices (computers, phones, etc.) to use. This is Access Point (AP) mode.
STA mode (aka client mode) is when a device is a client that is connecting to an existing AP. This includes your phones, computers, etc. when they connect to the AP you are broadcasting. But it also includes how you might connect your travel router to an upstream wifi network at a hotel or other such place. So, your travel router will operate in STA mode if you need to connect upstream via wifi. You'd assign this network to the wan firewall zone so that the upstream is treated as untrusted.
Typically, you'll want your travel router to broadcast a wifi SSID in AP mode for your own devices. So, per the above, you might also be using STA mode... your hardware needs to support STA + AP modes simultaneously. This is trivial when you have 2 radios (2g and 5g) and most single band radios are also fine. But this is not supported by very low end devices.
My question is, when the upstream AP is not available, will the Travelmate device start acting as a router?
That is:
Normally this will be the job whatever the upstream AP is connected to, so at that point the Travelmate needs to act as more than "just" a AP.
Background : I use my phone as a hotspot in my campervan/flat. I need something that can connect to the phone when it is near, but when i take it outside I still want my van/flat devices to be able to talk to one another. Will Travelmate allow this scenario.
Edit: thinking about some more, is it maybe always acting as a router, so eg the ip addresses were already handed out by Travelmate and the router behind the upstream AP is not aware of the STAs behind the Travelmate ?
In general, your device is always acting as a router. The only question is about the availability of the upstream (i.e. internet) connection.
Yes, in a typical configuration.
The typical scenario is as follows:
From the perspective of the travel router's AP mode, all of your devices are STA mode connections. So, typically yes, but this can be changed. In most cases, you'll have say your phone, computer, tablet, etc... these are all your devices and usually trusted so you'll probably want them to be able to communicate with each other. But you can enable wifi isolation which will prohibit that.
But to be clear, if the travel router is operating in STA mode to connect to an upstream network, that network does not have access to the devices behind your router (on its lan).
Your device will be a full fledged router.
The only reason that TravelMate might be essential is
Put another way... if the upstream network is not available (i.e. it was the hotel you stayed in last night, but now you're somewhere else with different wifi), you could experience a situation where your own wifi SSID does not start because of the lack of the old upstream connection. You'd be locked out of the device unless you have ethernet or another means of telling the system not to try to connect to the (non-existent) upstream network. Travelmate gracefully deals with that situation.
Yes, this should work. It may not reconnect when you arrive back, though -- you may need to manually connect to it and tell it to establish the connection to your hotspot again. Or, a simple restart of the travel router would achieve the same thing in most situations
The IPs being handed out to the devices in your campervan are not managed by Travelmate. That's just the normal router functions (dnsmasq in particular).
Travelmate is purely managing the upstream connection methods and gracefully handling the 'unavailable SSID' situation. It's important to note that there are a bunch of other really cool features in Travelmate, but at its core, it's just managing the upstream wifi connections (or lack thereof).
Thanks a lot for your elaborate response, much appreciated and that clears up some misconceptions I had.
Not automatically reconnecting seems to be a bit of a deal breaker though, having to undertake manual action each time i return is going to get annoying fast 
It is possible that it can scan periodically... I don't know though since I've never had a use case of a travel router that required auto-re-connection to an upstream network that may come and go.
Alternatively, as long as you have a multi-radio travel router, you can always have one radio dedicated to the upstream so that it runs in sta mode only (and thus doesn't cause problems for your wifi if the upstream is not available).