Having newly installed OpenWRT 15.05 on this router all seems to be going well except that I haven't succeeded in achieving a DSL connection. I've set it up with PPPoATM and the VPI/VCI as my current router (Linksys running stock firmware) and the same as this router running dd-wrt until I broke it.

The WBMR-HP-G300H page says it comes with Annex B and that I need to remove that and install Annex A. I've downloaded the .ipk file suggested but it's not clear to me what to do next.

Do I remove the Annex B with opkg remove <some package name which escapes me>? And if so, where do I put the .ipk file downloaded in order that opkg might find it amongst the available packages? I'm confused that /etc/config/network already has option annex 'a' in the adsl stanza.

Erm, as far as I know ADSL Annex A and Annex B are typically not only differences in software, but also in hardware. Which makes sense if one thinks about the main difference, Annex B carves out some frequencies to happily coexist with ISDN while Annex A only spares the traditional POTS frequency range. so I would guess that both use different high-pass filters at their inputs and hence are not electrically equivalent.

Yes, that's my understanding. But it doesn't actually address my question...

I really don't know about 15.05 anymore, I haven't used it in over a year. But if you install LEDE (for all intents and purposes the "new" OpenWrt until the release name changes back to OpenWrt, 17.01.4 is the current major version as of this writing) it is as easy as setting option annex "a" in the dsl configuration of /etc/config/network. When booting, the DSL firmware is patched on the fly to the selected Annex.

But, as moeller0 says, there's a good chance that you will not get your line to connect. If so, the line filters inside your router could be modified, but that's advanced soldering you'd be looking at.

(Last edited by metai on 19 Jan 2018, 15:18)

Ah, then just download the .ipk to your router's /tmp, unpack it manually:
tar -xvzf ./kmod-ltq-adsl-ar9-fw-a_0.1-1_lantiq.ipk
and unpack the data sub archive:
tar -xvzf ./data.tar.gz
then copy the firmware binary
cp ./lib/firmware/ltq-dsl-fw-a-ar9.bin /lib/firmware/ltq-dsl-fw-a-ar9.bin
then either edit
config adsl 'dsl'
    option annex 'b'
    option firmware '/lib/firmware/adsl.bin'
to
config adsl 'dsl'
    option annex 'b'
    option firmware '/lib/firmware/firmware/ltq-dsl-fw-a-ar9.bin'

or change the link adsl.bin to point to the new firmware.

Now is this a direct answer to your direct question? Probably not.
Does it solve the issue you brought up? Yes.

Oh, have you tried:
"opkg update ; opkg install kmod-ltq-adsl-ar9-fw-a_0.1-1_lantiq"
That way it should, assuming your openwrt installation is complete, pull the package from the configured servers and install it. You might need to add "--force-overwrite" as the link to adsl.bin will most likely conflict with the initially installed firmware.

Then again, following @metai's lead switching to lede 17.01.4 might be the easiest path (also a bit more secure as 15.05 is getting long in the tooth).

I have got this router and switching from annex a to annex b was no problem for me. It connected without a problem.

Thanks folks - the 15.05 image was the only one I could find which was indicated for WBMR-HP-300H.

After bricking it one more time I'm now on LEDE (as suggested by @metai) having installed WBMRA-squashfs-sysupgrade.bin from 17.01.4/targets/lantiq/xway/

It wasn't clear what the difference was between WBMRA and WBMRB as metai said both Annex A and B were incorporated in the build. (However, I'm not sure why he suggested advanced soldering might be needed -I've been soldering for around 60 years so I might be sufficiently advanced- as this router was working on the same ADSL line under dd-wrt until I bricked it, and before that on stock firmware.)

But having configured PPPoATM, the VPI/VCI and VCMux and checked /etc/config/network says Annex A, it still doesn't connect. The DSL light stays stubbornly off.

Here's what appears in the System Log when I click Connect:

Tue Oct 17 17:51:22 2017 daemon.info pppd[2475]: Using interface pppoa-wan
Tue Oct 17 17:51:22 2017 daemon.notice pppd[2475]: Connect: pppoa-wan <--> 0.0.38
Tue Oct 17 17:51:52 2017 daemon.warn pppd[2475]: LCP: timeout sending Config-Requests
Tue Oct 17 17:51:52 2017 daemon.notice pppd[2475]: Connection terminated.
Tue Oct 17 17:51:52 2017 daemon.notice pppd[2475]: Modem hangup
Tue Oct 17 17:51:52 2017 daemon.info pppd[2475]: Exit.
Tue Oct 17 17:51:52 2017 daemon.notice netifd: Interface 'wan' is now down
Tue Oct 17 17:51:52 2017 daemon.notice netifd: Interface 'wan' is setting up now
Tue Oct 17 17:51:52 2017 daemon.info pppd[2539]: Plugin pppoatm.so loaded.
Tue Oct 17 17:51:52 2017 daemon.info pppd[2539]: PPPoATM plugin_init
Tue Oct 17 17:51:52 2017 daemon.info pppd[2539]: PPPoATM setdevname_pppoatm - SUCCESS:0.0.38
Tue Oct 17 17:51:52 2017 daemon.notice pppd[2539]: pppd 2.4.7 started by root, uid 0
Tue Oct 17 17:51:52 2017 kern.info kernel: [  343.712887] pppoa-wan: renamed from ppp0
Tue Oct 17 17:51:52 2017 daemon.info pppd[2539]: Using interface pppoa-wan
Tue Oct 17 17:51:52 2017 daemon.notice pppd[2539]: Connect: pppoa-wan <--> 0.0.38

So what now?

I meant that some modems are limited by hardware to either Annex A or B, specifically by the component values on the highpass filter, amongst other parts.The only way to change that is by changing or bridging parts on the PCB, and that's quite delicate soldering. But since your device already worked on stock firmware, that should not be necessary.

First things first: Check whether your line actually synchronizes. On the command line, do

/etc/init.d/dsl_control status

and check if you get a connection.

(Last edited by metai on 23 Jan 2018, 21:30)

I'll swear I didn't change anything. Perhaps it was the cat. But ever since I threatened it with dsl_control status it got a DSL connection and the DSL light came on. It still wasn't making a DHCP client request to the ISP but I fixed that by setting a PAP/CHAP user name and password, which I was pretty sure my ISP (Talktalk) hasn't required for years.

So I think I'm back on the road. Thanks ppl for the help.