US Telco Support → FairPoint > Chronic reboots required Comtrend AR5381u

Chronic reboots required Comtrend AR5381u

Hello -

I have been suffering with 1-4 reboots per day for months now. Sometimes I may be lucky to get through 1 or 2 days w/ out a reboot. But it's rare.

Fairpoint has swapped out boxes, run line tests, etc. The probems of connectivity and the need for routine reboots persists. I probably have over a dozen calls logged. I've mostly stopped calling due to the lack of satisfaction I get from calling.

Normally I just reboot the box because I'm looking for resolution not debug w their less then knowledgeable 1st level support staff. 2 days ago I logged a call and asked for a tech to come out. Yesterday a field tech who was very thoughtful came by and did more line tests back to the CO and also within my house. He felt I had one bad phone in the house (which I have removed), and thinks my alarm system may have a "poor signature". But in general the line integrity is demonstrating to be very good.

I believe the issues are not necessarily at the physical layer.

Tonight I had time on my hands, and so with the failure which occurred this afternoon I figured I'd spend some time debugging rather than rebooting it immediately.

Here's what I found...

My wan IP *was* ping-able by the support staff at Fairpoint.
None of the devices which connect wireless had internet access.
The DSL & PPP status were represented as working in the web screens.
I had several thousand HEC errors on both up and down stream (this sort of points to line integrity which is confusing, or possibly bad hardware along the path. Maybe the Comtrend???)
The DNS primary and back up were pingable.
I was able to ping 8.8.8.8
I was not able to ping www.google.com

This leads me to believe the DNS proxy fairpoint is using was failing to handle my requests properly.

After rebooting and restoring internet connectivity, using the advanced screen I configured the DNS proxy to be disabled, but when I did that I lost internet connectivity. I don't understand the details of the proxy feature to know whether it can be by passed / disabled or not. It would seem not. Maybe in addition to disabling DNS proxy, I also need to point to a different DNS server???? If anyone has any positive *proven* experience and can offer specifics related to the AR5381u DNS screens I would appreciate it.

I pressed and pressed and pressed for them to connect me to one of their operations team members who understands IP, but what I kept getting was "that group is not a customer facing group". NO SH!T, but when the customer is requesting help, and the existing support staff can't grasp the problem, I'd expect an escalation.

I'm just about ready to switch over to timewarner cable...

Can anyone offer me reasons to stay or suggestions on how to better isolate and fix this problem on my end since clearly the operations team at Fairpoint is unwilling. They ONLY want to send a field tech. The field techs do not understand IP. They ONLY understand the layer1 testing.

Help, PAH-LEEEZE!!!

Welcome to BBR.

Residential routers proxy DNS requests. What this means is when the DHCP server in your router configures a client one of the parameters it tells the client is the address to use to make DNS requests. If you look at one of the clients on you LAN notice the DNS setting is probably pointing to the router, typically 192.168.1.1 or however you set up the addressing scheme for your LAN, rather then the actual DNS server provided by your ISP.

The router does not contain its own DNS server so whenever it gets a DNS lookup request (port 53) it simply forwards the request (proxies) to the real DNS server provided by the ISP. If there are more then one it tries the first, if that times out the second before giving up.

If you want to check if the problem is related to FairPoint DNS you can set the DNS server manually on the client. In Windows go to TCP/IP v4 properties and you will see settings for IP and below that for DNS with separate radio buttons. Leave IP set automatically but plug in the Google DNS address 8.8.8.8 or some other public DNS server and see what happens.

If the problem goes away you know it is a DNS problem. Just to be sure in Windows may want to flush the DNS cache. From the command line ipconfig /flushdns - or simply reboot your PC.

The error count is not particular useful in an of itself. Need to look at error relative to packets/frames. Errors should be very small percentage of total traffic.

Check the modem stats and see if the sync rate is correct for your speed plan and that margin is adequate. Should be at least 10 dB, the higher the better. Once it margin gets down to around 6 dB modem has a hard time syncing.

To see if inside wiring/equipment is degrading DSL temporally connect modem to phone company NID test jack. This disconnects inside wiring taking it out of the equation. If stats improve (greater sync speed or improved margin) something within your residence is degrading DSL. Since DSL is adaptive may want to go back and forth from normal location to NID a couple of time to get accurate result.

Something to keep in mind is not all Internet hosts respond to Ping, some IT departments disable it. When using Ping to test connection need to know in advance if the remote host normally responds to Ping. Both 8.8.8.8 and DSLreports.com respond to Ping.

/tom

The Fairpoint tech could have easily ruled out your inside wiring problems (IW for short) if he/she used their Sidekick test meter (meter looks like this). Unplug all devices as much as possible. Then disconnect the IW at the NI, hook up the Sidekick to the IW, set the meter to Stress and Leakage to look for issues. Next tech that gets out there, have them run those tests. Also have them run those tests on your loop with the Coil lifted at the CO (the tech has to call a CO tech to temporarily lift the coil). Should have no foreign voltage, Stress less than 30, No Leakage TIP/RING/GROUND, no load coils. I've found that many of the techs are lazy and won't do any real work, maybe a the minimum pull out their brown meter (which only tests resistance and misses a lot of issues). You could also ask the tech to cut out the Bridge Tap. Some will, some won't. Often times loop issues lie in the Bridge Tap. Back when I had Verizon DSL years ago, I had line issues and the tech cut out the Bridge Tap and that fixed all of my issues (DSL intermittent sync issues).

Thanks on next failure I will explore static dns assignment on a host. No failure today.

Thanks for the coil suggestion. He did test the iW as you described

Do you have a dedicated home-run for your modem? Is there a POTS splitter bridge module in your NI? Your alarm panel should be filtered if it isn't already.

Yes dedicated home run to the NI from the modem/office phone. I assume there is a splitter in the NI. That's a detail I don't know.

By filtering the alarm, do you mean it's something my alarm company should be doing? We have an external filter in the NI for the phones in the house.

The alarm is set up such that it over rides anyone being on the phone if an alarm call needs to be made.

Problem (as described in original post) just happened again, I logged yet another call w/ FP. I was unable to figure out how to set my dns on my Window's Vista desktop.

One think I noted is that I was on the land line and heard static, then went to the pc to do some work a few mins later and realized the problem was happening. The modem uptime showed the DSL uptime correlating to when I was on the phone or there about.

In the NI, the bridge module on the customer side should say ADSL Splitter, with a data connection and 3 filtered connections (they look like clear plastic rocker tabs with the red/green pairs sliding under each tab). If you have an older bridge module with screw terminals, then it is possible you don't have any filtering being done at the NI as most of the screw terminal type bridge modules that I have seen (probably over 400 NIs now) don't have any filtering.

Look for any external boxes near the NI (might be inside, but usually installed near the NI on home-runs); one might be an external POTS splitter. If that doesn't exist, then you probably have no filters in place, and will need to install them on all phones & the alarm panel. Unfiltered phones would cause static on the line when you pick up the phone, due to the DSL modem operating, and by picking up the phone or phone ringing may cause the modem to lose sync.