Kitz Forum

Broadband Related => Broadband Hardware => Topic started by: Weaver on January 05, 2018, 06:54:08 AM

Title: New ADSL modems around? (again)
Post by: Weaver on January 05, 2018, 06:54:08 AM
It's that time of year again. (Yes, I know, i know, I've asked this before, but this is a new year.)

Are there any new excellent ADSL modems out there that are superb on ultra-long lines, including VDSL ones that do ADSL extremely well, and including routers that can be put into straight PPPoE-modem modem?

VMG1312-B10A recap (stalled)

Last spring, I asked Andrews and Arnold to ship a ZyXel suffix -A (not -D) VMG1312-B10A wireless router to me, and it has been months now, but I haven't yet tried it yet, I’m very ashamed to admit. I can’t remember what the story with AA was back then: I think they possibly screwed up and thought it was to be a router and for one line even though I told them repeatedly otherwise. Apologies to AA for defaming them if not. The other thing though is that they for some reason didn't seem to want to sell me two more of them and I need three units of course. Maybe that was because they were running low on stock because of the changeover to the less-capable but cheaper -D units, don't know?

I can still get hold of some -A new routers on ebay and from amazon sellers. Would prefer new ones or nearly new. New are £60+ and I've seen second-hand ones for £35.
Title: Re: New ADSL modems around? (again)
Post by: kitz on January 05, 2018, 01:54:18 PM
I think the VMG1312-B10A is still one of the favoured modems.
 
Same as with the VMG8324/8924 B10A as they have internal noise filters built in not found in most other modems.
The chipset in the B10As are also better than that in the B10D. 
However the caveat is always there that may work best on one line may not always work best on another :/
Title: Re: New ADSL modems around? (again)
Post by: Weaver on January 05, 2018, 04:11:47 PM
A few questions:

1. What's the difference between an 8324, 8924 and a 1312?

2. In the earlier thread it said that I had the impression that the VMG1312-B10A supports monitored tones. Recap: Is that true, do we know this?

3. I’m worried that over time (a) the likes of ADSL2/ADSL2+ and will become a Cinderella subject for modem software designers, and there might be no improvements or innovation because the emphasis will be on the main market which is vastly dominated by VDSL2 and soon to be G.Fast. Even worse, (b) both targeted hardware support and even special testing on long lines might tend to become well-nigh non-existent, so that we might end up with ADSL kit that still works because the code is more-or-less frozen and there’s no reason to break it but it is pretty useless unless your ADSL line has a modest attenuation. What do you think?

4. Is it time to hoard some very high quality modems?

5. Does kit deteriorate a lot over time if it is not even in use?

I suppose the best thing to do is to start hoarding as late as possible, using your crystal ball to tell you when manufacturers are going to stop making some treasured units. I can see some second hand modems cheap on ebay et al, but I have no way of knowing for sure how old they are. With new ones, I suppose you have to hope they haven't been lying around in a warehouse for ages. Is there usually a way of telling the manufacturing date?
Title: Re: New ADSL modems around? (again)
Post by: Lil-Koby on January 05, 2018, 04:40:07 PM
Are you looking for a AIO Router or a device that will be used in bridge mode in front of another Router ?
Title: Re: New ADSL modems around? (again)
Post by: Weaver on January 05, 2018, 05:36:49 PM
For something to be used as a straight modem only (bridge mode), PPPoEoE-PPPoEoA, times three units, with my Firebrick FB2700 as the router/firewall/dhcp server etc.

I have three long ADSL lines each of which has a DLink modem doing PPPoEoE-PPPoEoA, and these lines are IP-bonded by the ISP, with the ISP's routers splitting the downstream traffic in correct proportion across the lines according to their different speeds and up/down state and my Firebrick does the same for splitting the upstream traffic. Regarding upstream, unfortunately my Firebrick has to be told what the current upstream rate of each of the lines is, it doesn't just ‘know’ and it doesn't have the technology to discern this information for itself from querying modems or better also getting dynamic status reports from modems or from eg BT.
Title: Re: New ADSL modems around? (again)
Post by: burakkucat on January 05, 2018, 10:53:46 PM
There is something about the ZyXEL VMG1312-B10A and IPv6 . . . I can't remember the details but I know of someone who does know -- jelv (http://forum.kitz.co.uk/index.php?action=profile;u=754). [Link to a thread elsewhere. (http://forums.thinkbroadband.com/aaisp/f/4572337-vmg1312-b10a-and-ipv6.html)]

It might be when used as a combined modem/router rather than just as a modem.
Title: Re: New ADSL modems around? (again)
Post by: Lil-Koby on January 05, 2018, 11:15:07 PM
If i understand you correctly you are doing some sort of Bonding or Load Balancing with your Firebrick FB2700 ?
For just ADSL(2+) most devices with BCM6338/48/58 chipset should work quite well but if you want a (V)VDSL2 capable device i would suggest something with at least a BCM63168 chipset, the best would probably be a device with BCM63138 ARM chipset.

TG589vac v2, BCM63168 (very cheap, used): ebay.co.uk (https://www.ebay.co.uk/itm/Technicolor-TG589vac-V2-wireless-modem-router-ADSL-VDSL-Wireless-AC/173042561231)
TG789vac v2 (TIM), BCM63168, ARM?(400mhz dualcore): Unfortunately this device is only available at amazon germany/france/italy
DGA4130, BCM63138, ARM(1ghz dualcore): ebay.co.uk (https://www.ebay.co.uk/itm/Smart-Modem-Plus-DGA4130/173071663281) (atm there is only one avalible on ebay)

But to be honest i can't tell how good the BCM63168 and BCM63138 chipset will perform on a long ADSL connection.
At (V)VDSL with a Broadcom Linecard on the other end they perform very well !!
I think they should also work quite well on ADSL(2+)...

Do you know the vendor(s) of your Linecard(s) ?
Title: Re: New ADSL modems around? (again)
Post by: banger on January 06, 2018, 12:31:00 AM
There is something about the ZyXEL VMG1312-B10A and IPv6 . . . I can't remember the details but I know of someone who does know -- jelv (http://forum.kitz.co.uk/index.php?action=profile;u=754). [Link to a thread elsewhere. (http://forums.thinkbroadband.com/aaisp/f/4572337-vmg1312-b10a-and-ipv6.html)]

It might be when used as a combined modem/router rather than just as a modem.

The VMG-1312-B10A when used in bridge mode simply passes IPV6 on as I am using an Asus DSL-N55U with 6to4 IPV6 configured on the Asus which works quite well as my ISP hasn't adopted native IPV6 yet.

I am of the understanding that when using the VMG-1312-B10A as a router/modem it does not pass on IPV6 to client machines whereas the VMG-1312-B10D with new firmware does.
Title: Re: New ADSL modems around? (again)
Post by: burakkucat on January 06, 2018, 12:42:43 AM
The VMG-1312-B10A when used in bridge mode simply passes IPV6 on . . .

I am of the understanding that when using the VMG-1312-B10A as a router/modem it does not pass on IPV6 to client machines whereas the VMG-1312-B10D with new firmware does.

Thank you for refreshing my memory. I am certain that you have reminded me of the correct facts.  :)
Title: Re: New ADSL modems around? (again)
Post by: Weaver on January 06, 2018, 01:15:17 AM
Thanks very, very much for those links.

This is quite a scary long list
    https://support.aa.net.uk/VMG1312-B10A:_Bugs#Problem_List
But I suspect that the list can be reduced down a lot if you are not using it as a router?

I saw one bug relating to badness in IPv6CP I think, which can be avoided simply by not getting the config info from ppp but hard-coding it, which is what I do anyway with my Firebrick.

I am not sure if there is something in there that might be a showstopper for me with modem-only mode. I'm getting pretty well scared off. It's impressive how cynical ZyXel is and how they refuse to fix any bugs, to force people to buy new kit perhaps? (I seem to have been incredibly lucky with my ZyXel WAPs given their ethics and attitude to software dev quality standards.)

@Lil-koby :
1) Yes IP-bonded three lines. The ISP does load splitting at their end at the individual IP packet level, not assigning TCP connections to lines, knows nothing about L4 protocols and a single TCP stream goes at triple speed. My own router does the same load-splitting for upstream traffic.
2.) No chance of getting any VDSL for the foreseeable if ever. If the USO ever happens and it actually turns out to be meaningful and useful, not just a con and an advert for satellite garbage, then we might possibly get a cab but then who knows it might even be FTTP if they have any sense at all, as everything would have to be done from scratch sending as there aren't any green boxes of any sort out here four miles from kind of civilisation.
3) I don't know what the hardware in the DSLAM/MSANs is now in the NSBFD exchange since they upgraded it to 21CN. I haven't dug around to have a look. (Was TI back in the old 20CN days of course which means absolutely nothing.) I don't suppose it's in some database somewhere?
Title: Re: New ADSL modems around? (again)
Post by: burakkucat on January 06, 2018, 01:32:44 AM
Thanks very, very much for those links.

This is quite a scary long list
    https://support.aa.net.uk/VMG1312-B10A:_Bugs#Problem_List
But I suspect that the list can be reduced down a lot if you are not using it as a router?

Yes, that is what banger has reported.

Quote
3) I don't know what the hardware in the DSLAM/MSANs is now in the NSBFD exchange since they upgraded it to 21CN. I haven't dug around to have a look.

A suitable modem with a Broadcom chipset will disclose it in response to the appropriate incantation. As an example, the following is the result from my ZyXEL VMG1312-B10D interrogating the exchange located, TalkTalk owned, MSAN --

# xdslctl info --vendor
xdslctl: ADSL driver and PHY status
Status: Showtime
Last Retrain Reason:   8000
Last initialization procedure status:   0
Max:   Upstream rate = 932 Kbps, Downstream rate = 5596 Kbps
Bearer:   0, Upstream rate = 763 Kbps, Downstream rate = 5120 Kbps

ChipSet Vendor Id:   IFTN:0x71c8
ChipSet VersionNumber:   0x71c8
ChipSet SerialNumber:   
#


I was told that it is a Huawei MSAN and we can see that the line-card chipset is identified as Infineon (now owned by Intel).

Quote
I don't suppose it's in some database somewhere?

I'm sure it is. But not publicly accessible and not something that Black Sheep would be able to access.
Title: Re: New ADSL modems around? (again)
Post by: Weaver on January 06, 2018, 04:14:14 AM
@burakkucat - I did once do that very same experiment using my old beloved Netgear DG834v3 and found that every exchange around here had the same chipset identifier as NSBFD.

So do we think that I’m safe enough to go ahead with the experiment because I’m only using the modem function? And almost all the bugs lie in the routing/firewall/wireless/chocolate sauce/Cadbury’s Flake/sprinkles/fries and onion rings? I think “no”.

* I'd say “no” because of the
(i) “session-id caching” bug which is an evil that affects even “bridge mode” - unless that got fixed later and AA has not updated the document.
(ii) “Intermittent loss of IPv6” bug - not sure if that means that modem-only modem users are affected, can’t tell one way or the other,
(iii) PADI interval bug (or semi-bug/undesirable).

I'd better ask AA before proceeding seriously as I don't want to end up introducing utter chaos which they end up dealing with, solely for a bit more speed.

The plus points might be: more speed possibly, more reliability because of the filter and benefits from monitored tones assuming that that is true.
Minus points: bugs!! stupid MTU back to 1492

I'm wondering if the -D is free of all these defects then?
Title: Re: New ADSL modems around? (again)
Post by: jaydub on January 06, 2018, 10:05:22 AM
I'm wondering if the -D is free of all these defects then?

Can't answer that question, but it's worth noting that the -D has a cheaper BCM63381 Broadcom chipset in it designed for budget modems, while the B10A has the same Broadcom 63168 chipset that is in the higher end VMG8324/8924s.

I'd ask A&A about them since they used to supply the -A, but now supply the -D and I'm sure they will have full visibility of the bug list for the -D version.
Title: Re: New ADSL modems around? (again)
Post by: vic0239 on January 06, 2018, 11:33:30 AM
I have a VMG1312-B10A on each of my lines, both in bridge mode to the Firebrick 2700. Both work flawlessly, the only drawback is the smaller MTU size. No issues with IPv6. I did have two of the -D versions from AA to try, but they underperformed in comparison to the  -A version (on my lines). You can access the modem via the WAN connection by adding a separate subnet to the Firebrick WAN definition.
Title: Re: New ADSL modems around? (again)
Post by: Lil-Koby on January 06, 2018, 04:24:04 PM
I would stay away from devices with BCM63381 chipsets, they tend to sync worse/lower than devices with 63168 chipsets.
Of course it also depends a little bit on the used driver version.
Quote
I don't know what the hardware in the DSLAM/MSANs is now in the NSBFD exchange since they upgraded it to 21CN. I haven't dug around to have a look. (Was TI back in the old 20CN days of course which means absolutely nothing.)
Hopefully your ISP dont use TI Linecards anymore. Just have a look with the command that burakkucat posted.

At my old ADSL times our local ISP used Alcatel and Texas Instruments Linecards. (Alcatel's were pretty good and the TI's were quite bad)
When ADSL2+ was in common use they upgraded everything to Infineon cards.
What I can remember of this time is that I used a modem with "Infineon Amazon-SE" chipset and it even worked better than my SpeedTouch 516iv6(BCM6338).
The only downside was that you couldn't adjust the SNRM with these Infineon Amazon-SE devices.

Nowadays Broadcom is the most common Vendor in use, at least in my country @(V)VDSL.
But for ADSL(2+) there are still a variety of diffrent Vendors in use over here... it's quite crazy.
Code: [Select]
Infineon, Broadcom, Centillium, Texas Instruments, Alcatel, Analog Devices, Globespan, IkanosIt was always a pain to find the right modem for a specific Linecard but it was also interesting to test diffrent modems/chipsets.
At this time i had at least 6 diffrent modems at home...  good old days. :D :bye:
Title: Re: New ADSL modems around? (again)
Post by: burakkucat on January 06, 2018, 05:27:14 PM
@burakkucat - I did once do that very same experiment using my old beloved Netgear DG834v3 and found that every exchange around here had the same chipset identifier as NSBFD.

Did Mrs Weaver put some of my catnip (https://www.youtube.com/watch?v=piPm0RFksn8&t=0s) into your breakfast bowl?  :-\

I read "NSBFD" as the serving telephony exchange identifier . . . i.e. North Scotland Broadford.
Title: Re: New ADSL modems around? (again)
Post by: Weaver on January 07, 2018, 01:16:05 AM
Sorry, I meant "as at NSBFD", missed out the word "at".
Title: Re: New ADSL modems around? (again)
Post by: burakkucat on January 07, 2018, 04:45:55 PM
Ah, I see. Inserting that missing two letter word makes all the difference.  ;)

Could you obtain some assistance to temporarily connect your DG834v3 to any one of your three circuits and then interrogate the DSLAM/MSAN as to the chipset on its line-card?
Title: Re: New ADSL modems around? (again)
Post by: ejs on January 07, 2018, 04:57:15 PM
I think all the BT exchanges recently upgraded to WBC/ADSL2+ use Broadcom line-card chipsets.
Title: Re: New ADSL modems around? (again)
Post by: burakkucat on January 07, 2018, 05:03:28 PM
I think all the BT exchanges recently upgraded to WBC/ADSL2+ use Broadcom line-card chipsets.

Thank you for that information. I think it would be helpful if "those who can" will please check.