HH5A DSL Reset/Retry on large custom DSL network

Good Morning
I have a large number of HH5A's running Openwrt (LEDE)

This is a really unusual setup so I'll put this at the end as a TLDR. My issue is that on the latest build and the original 17.x.x Once the modem goes down because of a loss of syc, or a noisy line the modem gets stuck at idle. Is there any way to programmatically kick the modem in the teeth to wake it up/restart it? At the moment I have separate hardware that power cycles the modem after so long if it can't see it's server but this takes longer than I'd like. Ideally I'd like to say if its idle for xxx then restart the modem. I don't see an obvious way to do this. ifdown/up was suggested but that doesnt see the ptm/dsl interface. With the BT stock firmware they do retrain so it's something with that specific OpenWRT implementation.

The setup is "weird"...
The modem is connected to a Huawei SmartAX MA5616 DSLAM, not the PSTN. We send out 4 PTMs (VLANS) and use the HH5A to break these out inside embedded DSL boxes. The box has a POE switch and a custom board that manages power, allows us to turn floodlights on/off, provides power quality and failure data and monitors the connection. If it gets no DHCP for 5 tries it reboots the lot and the same if 5 server uploads fail. The whole lot is spread over 600 acres providing WiFi, CCTV and network access. They work perfectly for this as we don't want WiFi just the VLANs. The HG612's are getting rare and have a braindead VLAN implementation and the HiFocus units just crash when you start playing with the switch. If anyone is interested there's some information on our YT channel, Rtech Lab.

ping some IP, if it's unavailable for X amount of time, do a reboot ?

or would perhaps service network restart do ? even rmmod and insmod, if doable ?

That's more or less what happens now. It just seems rebooting the modem would be faster and preferable. There is obviously an issue here too as the modem should come back up.

Now I think about it, that status screen must get it's data about the modem from somewhere, so maybe XX seconds in idle state?

/etc/init.d/dsl_control restart

will "restart" the modem, I'm just not sure how "deep" the restart is, i.e. if just the line is reset (and goes through the whole synchronisation dance) or the whole modem is rebooted (probably not). You'll have to try if it is sufficient. But I believe that's the closest you can get to resetting only the modem.

To reset the line, there is also a more direct command that can be sent through the CPE pipe, but I don't remember and also can't find it in my notes anymore.

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I think:

dsl_cpe_pipe.sh acs 2

should do the trick here. However no idea whether this is "low-level" enough to solve the OP's issue.

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I shall try both. I did find the acs command but it didn't seem to do much. Maybe I miss typed it. I'll let you know what works.

The acs command is supposed to initiate a retrain/resync, but it takes two to tango, so if the DSLAM has other ideas it might not actually retrain....

The DSLAM isnt doing anything odd. An unmolested HH%a is ok, as are the HG612, Hi focus and TP-Link units, if the BT firmware would let me do VLANs the way I needed to I'd be happy :slight_smile: Trouble is this is a really specific use case and how many people have their own DSLAMs?

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