[Cerowrt-devel] cerowrt-3.10.24-5 dev build released
fredstratton at imap.cc
Thu Dec 19 06:32:11 EST 2013
On 19/12/13 11:31, Fred Stratton wrote:
> 3 comments.
> Presumably you want these changes for some future use of the interface
> by a wider audience, rather than current users of ceroWRT.
> There is an requirement for this less sophisticated user to turn AQM
> on for ADSL. There are far more ADSL users than those who use fibre or
> cable. In the UK, offered a choice, about only 25 per cent of ADSL
> users migrate to fibre. The figure for cable is 10 per cent. This is
> in a fairly open market with competition.
> I would argue that the default should be 'on'.
> You state the choice in the interface pull down should be 'ethernet or
> 'atm'. Currently it is 'ethernet' or 'adsl', which semantically makes
> more sense, even though it uses a mystic, undocumented tc-stab option,
> namely 'adsl'.
> The 'adsl' option appears to work, which is why I advocate it.
> Finally, the fourth of these 3 comments...
> OpenWRT developers are working on the TP-LINK TD-W8970, a gateway
> device containing a Lantiq SoC. The device is cheaper in Europe than
> the US for a change.
> Lantiq apparently have open-sourced their code, and the device will be
> able to connect to the internet via ADSL2 or VDSL2, extending its
> Your interface will need to be modified again for a gateway device,
> rather than a router.
> On 19/12/13 10:49, Sebastian Moeller wrote:
>> Hi Rich,
>> On Dec 19, 2013, at 05:12 , Rich Brown <richb.hanover at gmail.com> wrote:
>>> Hi Sebastian,
>>>>> Perhaps we could extend the Interface configuration page to add a
>>>>> “Link uses DSL/ADSL:” checkbox right below the Protocol dropdown.
>>>>> Default would be off, but when customers go to the GE00 interface
>>>>> to enter their PPPoE/PPPoATM/ISP credentials, they’d see this
>>>>> additional checkbox. Checking it would feed that info to the AQM
>>>>> tab. (And perhaps there could be a link there either to the AQM
>>>>> tab, or to the wiki for more information.)
>>>> I am happy to include a link to a wiki, but I guess we first
>>>> need a wiki page :)
>>> Is this a challenge? Well, I accept! :-)
>>> is a draft. I recycled the images from a previous message and wrote
>>> the least amount that I could that is likely to be true.
>> This is great, thanks a lot. I have made a few changes to the GUI
>> yesterday, which hopefully improve the usability, so if the new GUI
>> passes muster with the cerowrt crowd, the screenshots will need to
>> change as you note on top.
>>> Please send me comments (or edit the page directly, if you have
>> I do not have edit permissions, so I just comments here.
>> Basic settings:
>> Why 85% as starting point? And can we give instructions how to
>> measure "degradation in performance", so that non-technical users
>> have a chance to actually optimize their own system?
>> Queueing Discipline:
>> Maybe we can add a link to the mail list page
>> Also can we note that it is recommended to turn ECN off for the
>> egress, as we handle packets before the bottleneck and dropping
>> packets actually allows us to send other more urgent packets , while
>> on ingress it is recommended to turn ECN on, as the packets have
>> cleared the bottleneck already, and hence dropping has no bandwidth
>> advantage anymore. Both dropping and ECN should have the same effect
>> on TCP adaptation to the path capacity.
>> Link Layer Adaptation:
>> I think the first question is: Do I have an ATM carrier between
>> your modem and your ISP's DSLAM? This typically is true for all ADSL
>> The second question is: Do I have overhead on the link outside of
>> Ethernet framing? This typically is true for users of PPPoE and
>> PPPoATM and even Bridging I think.
>> If the answer to any of these questions is yes, one needs to
>> activate the link layer adaptations.
>> In case of pure overhead select ethernet, in case of ADSL select
>> Fill in the per packet overhead in byte (see:
>> and http://www.faqs.org/rfcs/rfc2684.html). If the overhead truly is
>> zero and no ATM carrier is used, then select "none" for link layer
>> adaptation. (I changed this page, so the tc_stab htb_private
>> selection is under advanced options, and there is a selection of
>> "none", "ethernet", and "none" in the first drop down box, "none"
>> disables the link layer adaptation. Also the drop down box contains
>> some information which selection is relevant for which cases).
>> What’s going on here? Why do I need this?:
>> I think we should mention that only with the proper link layer
>> selected and the overhead specified cerowrt is able to assess how
>> large each packet is on the link to the ISP, and only then the
>> shaping is deterministic. (For ATM users without the adaptations the
>> shaper is stochastically too optimistic about the link capacity
>> (which is too say the shaper is too optimistic about the effective
>> packet sizes)).
>> Best Regards
>> Cerowrt-devel mailing list
>> Cerowrt-devel at lists.bufferbloat.net
More information about the Cerowrt-devel