DSLAM Ports - Lockups, Reset vs Refresh?

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datahawk

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Topic # 185610 29-Nov-2015 12:42

I have had VDSL working extremely well for more than 1.5 years connected to new Whisper cabinet installed in June 2014. DLM kindly puts us on the 17A profile with no issues and nice 58/10 Mbps (997) speeds.

VDSL equipment is a Netgear R7000 router connected through a Draytek DV130 modem in bridge mode, both on UPS's. The Draytek-130 is rock solid and never loses the VDSL connection unless Chorus or Spark maintenance is done.

I have had 2-3 occasions where our broadband has been out for an extended period which required calling ISP (Spark) support after both modem and router reboot attempts failed to reconnect.

During these extended outages, the modem VDSL connection has always remained connected showing no errors. The problem seems to be that the the PPPoE connection to my ISP account is locked out.

After contacting ISP broadband support, the operator seems to have access to a tool that either 'resets' or 'refreshes' the DSLAM port. The router will immediately connect when this is done and we are back online.

However, when the port is reset/refreshed by ISP staff, we lose the 17A profile immediately and the modem drops back to 8B but it stays on DLM-1 with a reported ping of 6ms. (It will take at least a month to 6 weeks before DLM bumps us back up to 17A)

This week I attempted to install a replacement Netgear R7000 router a few times. Every time I connected the new router it refused to connect to the ISP and appeared to lock the DSLAM port. When the original router was reconnected, it too would not reconnect until I called ISP support.

ISP support once again reset/refreshed the port to get a connection and we lost our 17A profile again.

My questions are:

1. What is the correct term - are DSLAM ports 'reset' or 'refreshed' ?

2. Do ISP support staff actually have access to a tool to do this in our cabinet ?

3. Should ISP support staff be brute force refreshing/resetting customer DSLAM ports when modems are clearly already connected with no DSL issues rather than finding a less brutal solution ?

4. Why does, the DSLAM port not reset itself, or is there procedure that can be followed that will allow the port to reset itself ?

5. Any ideas on why my port is locking up in the first place by simply fitting a new router would also be most appreciated ?

PeterReader

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Reply # 1437187 29-Nov-2015 12:42

Hello... Our robot found some keywords in your post, so here is an automated reply with some important things to note regarding broadband speeds.

If you are posting regarding DSL speeds please check that

- you have reset your modem and router

- your PC (or other PCs in your LAN) is not downloading large files when you are testing

- you are not being throttled by your ISP due to going over the monthly cap

- your tests are always done on an ethernet connection to the router - do not use wireless for testing

- you read this topic and follow the instructions there.

Make sure you provide information for other users to help you. If you have not already done it, please EDIT your post and add this now:

- Your ISP and plan

- Type of connection (ADSL, ADSL2, VDSL)

- Your modem DSL stats (do not worry about posting Speedtest, we need sync rate, attenuation and noise margin)

- Your general location (or street)

- If you are rural or urban

- If you know your connection is to an exchange, cabinet or conklin

- If your connection is to a ULL or wholesale service

- If you have done an isolation test as per the link above

Most of the problems with speed are likely to be related to internal wiring issues. Read this discussion to find out more about this. Your ISP is not intentionally slowing you down today (unless you are on a managed plan). Also if this is the school holidays it's likely you will notice slower than usual speed due to more users online.

A master splitter is required for VDSL2 and in most cases will improve speeds on DSL connections. Regular disconnections can be a monitored alarm or a set top box trying to connect. If there's an alarm connected to your line even if you don't have an alarm contract it may still try to connect so it's worth checking.

I recommend you read these two blog posts:

- Is your premises phone wiring impacting your broadband performance? (very technical)

- Are you receiving a substandard ULL ADSL2+ connection from your ISP?

I am the Geekzone Robot and I am here to help. I am from the Internet. I do not interact. Do not expect other replies from me.

Jarsky

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Reply # 1437212 29-Nov-2015 13:20

1. What is the correct term - are DSLAM ports 'reset' or 'refreshed' ?
Either, its the same thing - the correct term is Refresh. Theres also a PVC rebuild that can be done if need be.

2. Do ISP support staff actually have access to a tool to do this in our cabinet ?
Yes, they can access it via the Chorus Gateway

3. Should ISP support staff be brute force refreshing/resetting customer DSLAM ports when modems are clearly already connected with no DSL issues rather than finding a less brutal solution ?
Not sure what you mean, you advised that the sync was down? Either way, refreshing doesnt have a negative effect other than resetting DLM on VDSL lines - which isn't necessarily a bad thing either
In the old FIPD days, ISP's had much more control over the cabinet, and could even lock out entire cards if need be. They also had visibility of all other connections on that card/cabinet, to diagnose if it was a wider issue - but they cant do that anymore with the Wholesale division.

4. Why does, the DSLAM port not reset itself, or is there procedure that can be followed that will allow the port to reset itself ?
Because it shouldn't generally *need* a refresh - but sometimes it locks and the only thing ISP's have access to is refreshes which will release the lock.

5. Any ideas on why my port is locking up in the first place by simply fitting a new router would also be most appreciated ?
Could be a faulty port, ports do go bad. They could try swapping you to another port if theres one spare.

datahawk

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Reply # 1437222 29-Nov-2015 14:21

Jarsky: .... Not sure what you mean, you advised that the sync was down?

Many thanks for that info. Most helpful in clarifying this for us.

In regard to Q.3 comment, no, the actual VDSL modem sync to the DSLAM has been fine on all occasions that this has happened.

The Draytek modem in bridge mode shows a perfectly active 17A sync around 58/10 Mbps but the router has been disconnected from our Spark account. All attempts at re-connection to the internet fail....

If I dutifully reboot the Draytek before calling support it always re-sync's fine (but I usually get a slower speed due to DLM thinking I have a line issue, but it remains on the 17A profile.)

If I reboot the router, manually try reconnect, etc etc, nothing happens. I have spent an hour or more trying to get a reconnect with no results.

Sometimes it will automatically reconnect around 20-30 minutes later but the other times I have been waiting (on hold) for more than 1.5 hours (with the router in 'always on' mode trying and failing to get a Spark account connection). I'm then forced to have ISP support reset the port.

As above, the lock outs have only happened a few times and I'm trying to establish if it is port fault, router issue or something else.

After the port is reset, any brief outages caused by Chorus or Spark maintenance usually don't effect the router. It automatically reconnects as expected.

Lorenceo

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Reply # 1437223 29-Nov-2015 14:23

Seems odd to me that the DSLAM port would chuck a hissy over a device which isn't directly connected to it being changed. Do you leave your modem on while changing things on the router?
What happens if you try with the Spark supplied modem in bridge mode instead of the DV130?

datahawk

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Reply # 1437233 29-Nov-2015 14:41

Lorenceo: Seems odd to me that the DSLAM port would chuck a hissy over a device which isn't directly connected to it being changed. Do you leave your modem on while changing things on the router?
What happens if you try with the Spark supplied modem in bridge mode instead of the DV130?

Yes, that's how I'm looking at it. The DSLAM is talking to the Draytek with no issues. It is not a sync problem. (The Draytek firmware was also updated between lock outs to ensure it was not the issue.)

The Netgear R7000 is just a PPPoE passthrough login to Spark that normally works fine with no issues but I get locked out for unknown reasons.

Yes, I did leave the modem connected when I installed the new router. But even a reboot of the modem after that does not solve the issue. (it may have something to do with that, but if I reboot or power off and on the router while the modem is still connected, it usually reconnects with no issues or lockups.)

I have not tried to use the Huawei modem in bridge mode. My main issue is that my network is very active for my clients and I have difficulty in taking it down for anything but a very short period but I may need to try that in the future.

This weeks issue may just be a new faulty router, but it is strange that when I try to use it, I get locked out of my connection.

Jase2985

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Reply # 1437237 29-Nov-2015 15:06

maybe try removing the bridge for a little while and see if that helps? if not maybe try a new Modem and see if it continues, that way it rules out everything on your end.

unfortunately if you want to try to find an issue you are just going to have to have your network down for a little while while you fault fine. in the long run it will be worth it.

Lorenceo

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Reply # 1437253 29-Nov-2015 16:07

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Sounds more like an ISP thing to me rather than a Chorus/DSLAM one. Something on your ISP's end not realising your PPP session has dropped, assuming you're still connected and ignoring connection attempts until a timeout has expired maybe?

I've had the port my line's connected to lock up in the past, requiring a port refresh to fix. Different symptoms to yours though. Line would drop sync and refuse to resync until a port refresh had been run, or a fault had been logged.

BarTender

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Reply # 1437258 29-Nov-2015 16:25

To me it sounds like you are on a slightly iffy port. Normally ports shouldn't require a reset, but it can be done by ISP staff using Chorus SPM. But normally it should never be required and tends to be tried as a last resort before sending a tech out.

Not much that can be done apart from asking if you could get swapped onto another port. Which Chorus may charge for.

If it only happens once or twice a year you may have a hard time convincing someone to do something about it.

In regards to the PPPoE session, on the ISP side there is very little config / control that can be done. You as an end subscriber turns up on the end of a double tagged VLAN with a PADI request and the BNG starts bringing up. That PADI is generated by the ISAM and the only issues that can occur is if you were on an ADSL (not VDSL) connection and the PPPoE session was ripped down by the BNG without sending a PADT to the ISAM then there is a 5 minute timeout before the ISAM starts sending PADIs again.

mercutio

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Reply # 1437288 29-Nov-2015 17:03

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As Jarsky mentioned PVC rebuilt should fix it, without upsetting your 17a.

I suspect you're hitting MAC limits and have too many mad addresses on the system.

datahawk

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Reply # 1437313 29-Nov-2015 17:32

Lorenceo: Sounds more like an ISP thing to me rather than a Chorus/DSLAM one. Something on your ISP's end not realising your PPP session has dropped, assuming you're still connected and ignoring connection attempts until a timeout has expired maybe?

I've had the port my line's connected to lock up in the past, requiring a port refresh to fix. Different symptoms to yours though. Line would drop sync and refuse to resync until a port refresh had been run, or a fault had been logged.

Yep, I agree and I would love to get hold of someone at Spark to look at my connection logs for the past week. BUT, I have no idea who to contact ?

They would have log files.... wouldn't they.... maybe.... somewhere? :)

datahawk

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Reply # 1437318 29-Nov-2015 17:40

BarTender: To me it sounds like you are on a slightly iffy port. Normally ports shouldn't require a reset, but it can be done by ISP staff using Chorus SPM. But normally it should never be required and tends to be tried as a last resort before sending a tech out.

Your words 'last resort' are my understanding also in regard to the resets and that is why I get a little peeved when my 17A profile is killed each time. Particularly when the modem is still sync'd perfectly to the DSLAM.

I can also assure you that the last two Spark support people I talked to, pushed THAT last resort reset button pretty well immediately!

In both cases, I had not even finished explaining that I have no internet connection when the router connected while looking at it. When I asked them exactly what they just did, they just say that they reset the port for me.

datahawk

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Reply # 1437319 29-Nov-2015 17:42

mercutio: As Jarsky mentioned PVC rebuilt should fix it, without upsetting your 17a.

I suspect you're hitting MAC limits and have too many mad addresses on the system.

MAC limits ? - Can you elaborate on this for me and others maybe ?

mercutio

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Reply # 1437364 29-Nov-2015 19:37

datahawk:
mercutio: As Jarsky mentioned PVC rebuilt should fix it, without upsetting your 17a.

I suspect you're hitting MAC limits and have too many mad addresses on the system.

MAC limits ? - Can you elaborate on this for me and others maybe ?

If you're bridging and there are a lot of mac addresses then the port will only hold onto so many.

You can see the macs on the modem with telnet usually using a comamnd line:

# brctl showmacs br0

I'm not sure where something simple is to try to explain it more thoroughly, but google may help.

Basically every single ethernet device will have an associated mac address, and if you bridge and add a whole lot of devices then there is only limited capacity to store so many - so if you bridge to a switch, and there are multiple computers plugged into that switch but only one of them doing the pppoe you can easily hit the limit while still having something work most of the time.