Looking for cheap DSL router with Annex J and phone support


I'm looking for 2 cheap DSL routers to use with DSL 16Mbit/s Annex J. At least one should also have phone support.
It doesn't have to be superfast, it should only be provided with OpenWRT updates for long enough.

Best regards

Phone support shouldn't be part of your requirements.

First of all, there are several completely orthogonal questions (ISP side):

  • POTS (classic analogue)
  • ISDN
  • SIP

As well as LAN (phone) side:

  • FXS (analogue)
  • DECT/ cat-iq 2.x
  • ISDN
  • SIP

All of which might be cross-connected...

WAN side, OpenWrt only supports SIP, LAN side SIP would be easiest - FXS ports only via chan_lantiq (on supported hardware) via asterisk (unless you're an asterisk specialist, you don't want to go there).

ISDN is dead, POTS a dying breed - FXS ports 'difficult' (asterisk), DECT has zero linux support; but SIP is easy (needs no OpenWrt side support, just matching VoIP/ SIP hardware (pbx, ATA, SIP DECT bases, SIP phones).

Furthermore there aren't that many chan_lantiq supported routers either (AVM's Fritz!boxes are not chan_lantiq supported), and those that are there, tend to have other issues (low flash/ RAM, bad and slow wireless or no OpenWrt support).

Your options would be better, if you could drop native phone support from the requirements of your OpenWrt router (and sort those requirements by other hardware).

yes, ISDN support would be conceivable, FOSS software exists via mISDN and asterisk, but the OpenWrt integration would be your job to sort out - and ISDN/ mISDN is effectively dead. SIP would make your job much easier.


I'm living in Germany where it's all IP now afaik, and I can use my phone number via SIP, so on the WAN side it has to be SIP. On the LAN side I want to use an analog phone with a TAE plug like this one. Do I understand you right, that chan_lantiq is needed to use those TAE ports on a router?

I hope the other end of the cable is an RJ11/RJ12
and you can always just get a Cisco voip adaptor like this


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SIP makes it easy.

You have a couple of options:

  • the one I chose, was getting a low-end (OEM supported/ non-EOL) AVM Fritz!Box (with the OEM firmware/ Fritz!OS) as SIP pbx, SIP ATA and DECT base, this allows you to connect 'anything' (classic analogue phone/ fax machine, DECT/ cat-iq 2.x handsets, SIP desk phones) and can be configured as in IPoE mode exclusively for its phone features (disabling its internal modem, routing features, WLAN, etc.)
  • getting a SIP desk phone (e.g Grandstream or Yealink have quite nice devices on offer)
  • getting an SIP ATA, as Lucky1 already suggested
  • there are also SIP capable DECT bases (compatibility with existing DECT handsets needs to be checked)

It depends on what phones you currently have - and what features you need and how the cabling situation is like in your home (it may be more (economically and feature wise) reasonable to replace the phone(s), than buying adapters to keep the existing phone(s) working, but the later is possible as well).

The plug isn't interesting, what's more interesting would be the phone(s) you're currently using (IWF/ MWF, DECT, wired) and their number.

So what phones do you have? How many?
What are you looking for in terms of your phones?
What are the (cabling-) constraints you're dealing with?

On the handful of lantiq vr9 (non-AVM!) routers that are supported, yes - asterisk with the chan_lantiq plugin. It's possible, but I strongly recommend against it (configuring asterisk is complex and keeping it secure is even more of a challenge); personally I successfully tried it on an O² Box 6431 (but I don't dare to expose that setup to the open internet), however that device is marginal (64 MB RAM is tight, 16 MB flash are very tight for asterisk, only 100 MBit/s ports, 'not-good' 2.4-GHz-only WLAN, the initial flashing is complicated), but it's supported by chan_lantiq. Really, save yourself that kind of trouble and research your alternatives, you don't want to go there.

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It's one phone, a Siemens euroset 5010, so it's wired and no DECT. Unfortunately I don't know what IWF and MWF are... :sweat_smile:
There also is a change at my requirements: I would also want to use a printer with fax function. I don't have it yet, but according to the manual, the phone would be connected to the fax printer, so the fax printer would be connected to the router. Would that work?
And if I use a router without lantiq vr9 and chan_lantiq, how would I connect the phone to the router, since I can't use the TAE port(s)?

If the phone is in range of a LAN cable, e.g.:

There it gets more complicated, this is the part where I would suggest looking into a small Fritz!Box (7510/7520/7530) for the phone requirements (and your own OpenWrt router/ modem in front). These small models offer only a single analogue port, so you'd still want an SIP/ DECT cat-iq 2.1 phone, but they come with an integrated pbx, fax functions (receive and send without a connected fax machine, but you can connect one on the analogue port) and answering machine.

Not to forget it, Lucky1's suggest for a simple SIP ATA (VoIP to 1, 2 or 4 analogue (FXS) phone ports) from, e.g. Cisco or Grandtstream, is a valid one as well, but it wouldn't be my first choice.

Obviously there are bigger phones as well (Grandstream or Yealink are decent options, Cisco only for masochistic specialists, etc.). Hint, SIP phones are typically designed with PoE in mind, but they can be operated with a simple PSU as well (some vendors include them in the box, some don't - keep an eye on this for second hand offers).

The second hand markets are a viable source for these things as well.

A SIP ATA looks like the easiest choice, and it may be sensible if you have strong reasons not to touch the existing phone(s), be it because you really want to keep your W48 or early FeTAp running - or if you're dealing with older folks who wouldn't accept change (as in a new phone) easily, but for simple setups, with few devices and little constraints, it does make sense to look at native SIP or (SIP-) DECT devices.


Alright, thanks so far! I will think about the options presented regarding the use with fax and phone.
So, which routers would meet my needs for use without phone and fax?

I went from ADSL2+ with Annex B straight to VDSL2+vectoring/ profile 17b (and am now on ftth), so I skipped experiences with Annex J myself…

If we were talking about VDSL, I would probably recommend an ipq4019 based AVM Fritz!Box 7520 or 7530 (careful, there are different hardware revisions, revB or the AX variants are NOT supported and will never be), which should be well supported by OpenWrt and sporting decent system specs. but I have no idea how its drivers deal with ADSL (they're mostly tuned for VDSL2 and super-vectoring/ profile 35b, while the OEM firmware should cope with that, I'm not certain that the OpenWrt drivers would be great for this).

Personally I made good experiences with the BT Business Hub 5 Type A, but as that's an Annex A device, it's only usable for VDSL in Germany, but my main setup while using xDSL was a dedicated xDSL modem (Draytek Vigor 130B) and then a nicely supported OpenWrt router (starting out with a TP-Link TL-WDR4300 (long ago), then moving to ZyXEL nbg6817 - but if you split modem and router tasks, you can choose your router freely).

@moeller0 probably/ hopefully has better advice for ADSL with Annex J than me.

My experiences with splitting, modem, router, and phone features worked out well for me, it's not the cheapest approach (and with ADSL2/ Annex J in mind, you might not need top router/ AP performance, so taking a cheaper approach can be sensible), but on the other hand it allows cheaper upgrades of the individual components, should your (WAN-) situation change (just replace the modem, no need to touch router or phone).

        /                 /      |      \
[computers] [wireless devices] [...] [phone-only Fritz!Box]
                                      /        |         \
                           [SIP phones] [DECT handsets] [analogue fax]
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ATM support is currently broken in the driver (see this topic). So, the ADSL line definitely wouldn't work on a 7520/7530 running OpenWrt.


I have to take a pass on that, I also switched from traditional ADSL to VDSL2 (more then a decade ago) and never tried ADSL@AnnexJ.

I ended up doing something similar, only due to lack of knowledge that FritzBoxen can be used as SIP-basestations I bought a relative cheap Gigaset SIP/DECT base with a handset, which also just works... (given the price of second hand FB's I probably would go FB next time, but as long as the gigaset still works, I am not eager to exchange it)

I own a BT HH5A I do not need any longer and also a Zyxel VMG1312-B30A (broadcom-based modem/router that can be used as bridged modem) that is sitting on a shelf doping nothing (the Zyxel obviously is not an OpenWrt router, but can be used to complement an OpenWrt router).
@msfm44 if interested send me a PN, or have a look at second hand auction sites...
Note, I have not tested either of these with ADSL let alone Annex J.

I've searched a while and found some devices, which could be of interest. But I don't know how well they are being tested, since they seem old.

  1. D-Link DSL-2751 - Found it on firmware selector, but there is no wiki-page, so I don't know, how well it is supported
  2. TP-Link TD-W8970B - The version without B is supported by OpenWRT, don't know if this applies also for the B version. Without B there at least was an issue with the switch, but I'm not sure if it's still a thing.
  3. TP-Link TD-W8980B - The version without B is supported by OpenWRT, don't know if this applies also for the B version. Without B WiFi 5GHz at least wasn't working, don't know if it persists.
  4. TP-Link TL-WDR3600 - For 15.05 it is reported, that it hangs occasionally. Again I don't know if it' still a thing.
  5. NETGEAR WNR2200 - Here I couldn't find out if it supports Annex J.

So, does anybody know further about those devices, if the problems mentioned persist, if they are likely to work properly after all these years? And does anyone know, if the NETGEAR device supports Annex J?

No modem and 8 MB flash are getting tight (anf 802.11n is nothing to write home about), especially without modem requirements, there are much better ac/ ax devices around.

I realize what you are looking for, but 16/128 and ac should be the bare minimum to aim for. If you go with a dedicated modem (OpenWrt or not), mt7621a+mt7915DBDC might be a decent cheap option.

Disclaimer: I did not check the specs of any of your other options, yet - but from faint memories, neither of the model names leave me with a warm and fuzzy feeling.

WRN Wireless Network Router it's in the modem name no dsl it would start with a D