As, the title says, is it possible to connect a standard ADSL cable to a RB4011?
I want to avoid having the ISP modem at all. I don't have a lot or space where to put it.
Unfortunately, on my location only DSL is available. No cable, no optics.

So, I have a standard telephone (RJ11) wall socket and the RB4011.
RB4011 doesn't have any RJ11 ports, only RJ45.

Is it possible to patch this to work somehow?
Maybe just replace the RJ11 wall socket with a RJ45 one and wire the telephone wires differently?
Also, I see there are RJ11/RJ45 cables and adapters out there. Would those work?
Although I don't see how could this be any different than replacing the wall socket, and wiring it properly.

From what I've briefly read, it's not advisable to plug in a RJ11 jack into a RJ45 socket directly.

Obviously not, also because if they have a different name, they won't be the same, right?

No, this is not possible. The RB4011 does not support ADSL.
In theory it would be possible to have a SFP module with an ADSL modem and plug that in the SFP slot of the RB4011.
In practice that does not really work, due to:
- the questionable quality of the available SFP ADSL modems
- the lack of any monitoring of the modem parameters via RouterOS

So you need an external modem. Maybe the ZyXEL VMG4005-B40A is something for you, it could be smaller than the provider modem.
(I use it myself with a RB4011)

Must be tested if work as media converter for your adsl to interface usable on RouterBOARD side.

Thank you for the reply.

Ahhh, I guess I'll need to find some room for the ISP modem.

I won't buy a new modem. I don't see much sense in that. It can't be that much smaller.
I was trying to get rid of a piece of hardware, not spend money on a new one.

Too bad I didn't think of this before when I bought the RB.
I just assumed it had a modem and and a RJ11 socket somewhere.

Btw. if optics ever become available (little chance of that), that would work, right?
I would just plug it in the spf port, and could eliminate the ISP modem?

@rextended这个盒子看起来很有趣。尽管(presuming it works), is there any advantage of this compared to just using the ISP modem? It's an additional box I have to put somewhere and power, one way or the other. The only advantage I see is that it looks smaller than a typical adsl modem

The box that rextended showed does not work in your case. The ZyXEL box I showed will work.
The advantage of using a plain modem instead of a provider-supplied one is that you can avoid having double NAT, i.e. you have the public IP directly on the MikroTik.
It depends on your usage scenario if that is important. And it may also be that you can configure your ISP modem to "modem only" (transparent) mode.
When you get optic fiber, it depends on your provider what you can do. Usually you will get a termination box from the provider that converts optics to RJ45 ethernet.
But in some cases you can get bare optics, arrange a proper SFP yourself, and plug it into the RB4011.

The advantage of using a plain modem instead of a provider-supplied one is that you can avoid having double NAT, i.e. you have the public IP directly on the MikroTik.

But if I put the ISP router in bridge mode, won't that eliminate double NAT?
I mean it will only be used as a modem. It won't do any routing.

Yes, you can do that as well. When the ISP (and the router) allows it.

These are pretty popular in Australia:https://www.proscend.com/en/product/180-T.html

I mentioned those in comment #3. I have bought one, but:
- it achieved much less line speed than the Draytek 130 I had at that time
- it ran very hot in a fanless router
- and worst of all MikroTik does not want to support them so you cannot read the line parameters via the SFP tab on the sfp1 interface.

Since then, my line has been upgraded to profile 35b so I cannot use it anymore and now use the ZyXEL external modem.
It sure would be nice when there was a well supported solution like that, but MikroTik does not care about DSL, they think everyone has fiber or will get it soon.
(which is true in their region of the world)

Not everyone has LAN/Fiber, I have a Coax DOCSiS modem put in bridged mode.

Find a DSL modem that supports bridged mode or some passtrough mode.

depending on which kind of adsl plan you were using you could probably also consider the tp-link td-8616 as I know that it'll natively stay in ppoe mode even after a hard power cycle

Thank you for the suggestions, but I'm really not looking into buying a modem.
Those things aren't cheap. They cost almost as much as the RB. I'd rather spend that on some other part of the network.
And there are no guarantees they will work with some ISPs, especially if you consider IPTV, VOIP etc. And I end up having to use the ISP one anyway.
Since I don't have an ISP yet, I'll just find one that is willing to give me a router which can be put in bridge mode.
I'll just have to be creative with physically finding room for it.
As a last resort, I'll screw it to the ceiling of the bottom floor, and run the cable back up to the RB

好吧,当你免费线东西和路由器is somewhere else than the phone line, it can actually be best to put the modem close to the phone line termination and run an ethernet cable to where your router is.
(low-quality phone wire can decrease the line quality, in my country the ISP always tells you to put the modem immediately at the phone line demarcation point)