Consolidated Communications & Frontier ADSL DMT Static IP setup

I’m currently rocking it at the family beach house in Scarborough Maine, serviced by the glorious new cable conglomerate Spectrum. They have now deployed faster internet speeds in the area, offering up to gigabit plans on DOCSIS 3.1 (I believe).

Recently though they had a 12 hour outage where the entire beach lost TV and internet. That was a bummer (everyone was wandering aimlessly about outside in tears). So I went out in search of an additional ISP to achieve redundancy.

RedZone wireless has acceptable reviews, but unfortunately they were unable to offer service to my address due to land obstruction.

This left Consolidated Communications, which still offers DSL service in the area. They’re now offering (in my area) 1.5 mbps DSL service without a phone line (life pro tip: disable ad blocker to query service for your address) for ~$23.79/mo, which seemed acceptable for a backup option, particularly to keep the IoT devices running if we want to cancel Spectrum over the winter, etc. I also had the pleasure of working over DSL service on Vashon Island outside Seattle, and it’s doable.

Configuring the DSL modem

Configuring DSL modems in static IP mode is apparently somewhat of a lost art (the tech spent literally hours on the phone trying to find the one person at the support center who still knew how to do this setup).

First note: in my location, Consolidated has a positively vintage ADSL setup which negotiates as ADSL_G.dmt. As far as I can discern, DMT is a more noise resistant mode of DSL that is limited to 8 mbps / 1.2 mbps or so. For negotiation, they’ve provided me with a static IP service. It does not use PPPoE or any such magic. Do not select PPPoE or PPPoA as it will not function or negotiate.

The simplest configuration:

  • Set the modem to ATM mode.
  • Enable modem “bridge” feature.
  • Connect computer to LAN port (with Trendnet; sometimes WAN on others like ZyXEL?)
  • Open up your computer’s (or router’s) IP settings, and provision the address they provide into the IP settings. I’m in 64.222.XXX.XXX/24 with a router at the .1 address.
  • Once you do this, your computer will route.

If the router supports IPoE, you can configure the same IP address, subnet, and default gateway into the router. However, not all DSL modems from the modern era seem to support this static IP mode.

Other miscellaneous settings (most default):

  • UBR without PCR service category
  • LLC encapsulation mode
  • VPI 0, VCI 35 (both default)
  • I believe you can enable a VLAN on your router and set the same VLAN on your router (will test)
Trendnet ADSL DMT bridge configuration

Choosing a modem

ADSL2 modems are getting hard to find. Consolidated offered to sell me one for $160 or rent for like $12/month, which seemed absurd. I attempted to buy my own, but the router I bought does not support IPoE, however any router can be used in bridge mode to a different router.

TrendNet AC750 Wireless VDSL2/ADSL2+ modem

I purchased a TrendNet AC750 Wireless VDSL2/ADSL2+ modem off of eBay. I ran into two problems with this modem:

  • No native IPoE support for DSL, so it will only work in bridge mode.
  • For some unknown reason, the noise figures on this router are far inferior to the ancient dinosaur router the tech installed (attainable rate was something like 3700 kbps as opposed to 9352 kbps on the Comtrend).

Comtrend AR-5319

The installation tech found this dinosaur somewhere in the truck. It supports IPoE and negotiates to 9352 kbps attainable rate, which would allow me to order their 3mbps service. However, the management UI has a “security check” requesting I solve a CAPTCHA which reappears every 30 seconds, which makes using the config UII maddening.

ZyXEL C1100Z

A more modern router that I just ordered on eBay. Hopefully this will get me:

  • A UI that doesn’t make me want to kill myself.
  • Higher negotiated rate.
  • Bridge mode.

I assume it doesn’t support IPoE config.

Conclusion

With the new rate plan ($24/mo without phone service for DSL in Maine) I think that this service offers a compelling Plan B internet for your residence. The config is a bit of a nightmare, so I hope this article explains what I could not find with the google XD

Miscellanea

Interestingly when trying the Trendnet I get a higher SNR but also higher attenuation:

Comtrend stats page shows 40.5 dB attenuation w/ 20.1 dB SNR
Trendnet shows 52.5 dB attenuation but 27 dB SNR; much lower attainable rate.

Same phone wire and everything…maybe I will check with the ZyXEL and report back.

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