Re: [Softwires] draft-ietf-softwire-lw4over6 excluding Well Known Ports

Hi Woj,

Here’s an example from an lwAFTR binding table. In this case, there’s 4096 ports per client (k-bits =12, a-bits=0). PSID 0 just isn’t in the table.

2001:10f:60:6ff::0:b4 1.2.30.126 PSID 4096
2001:10f:60:6ff::1:b4 1.2.30.126 PSID 8192
2001:10f:60:6ff::2:b4 1.2.30.126 PSID 12288
2001:10f:60:6ff::3:b4 1.2.30.126 PSID 16384
2001:10f:60:6ff::4:b4 1.2.30.126 PSID 20480
2001:10f:60:6ff::5:b4 1.2.30.126 PSID 24576
2001:10f:60:6ff::6:b4 1.2.30.126 PSID 28672
2001:10f:60:6ff::7:b4 1.2.30.126 PSID 32768
2001:10f:60:6ff::8:b4 1.2.30.126 PSID 36864
2001:10f:60:6ff::9:b4 1.2.30.126 PSID 40960
2001:10f:60:6ff::a:b4 1.2.30.126 PSID 45056
2001:10f:60:6ff::b:b4 1.2.30.126 PSID 49152
2001:10f:60:6ff::c:b4 1.2.30.126 PSID 53248
2001:10f:60:6ff::d:b4 1.2.30.126 PSID 57344
2001:10f:60:6ff::e:b4 1.2.30.126 PSID 61440
2001:10f:60:7ff::0:b4 1.2.30.127 PSID 4096
2001:10f:60:7ff::1:b4 1.2.30.127 PSID 8192
2001:10f:60:7ff::2:b4 1.2.30.127 PSID 12288
2001:10f:60:7ff::3:b4 1.2.30.127 PSID 16384
2001:10f:60:7ff::4:b4 1.2.30.127 PSID 20480
2001:10f:60:7ff::5:b4 1.2.30.127 PSID 24576
2001:10f:60:7ff::6:b4 1.2.30.127 PSID 28672
2001:10f:60:7ff::7:b4 1.2.30.127 PSID 32768
2001:10f:60:7ff::8:b4 1.2.30.127 PSID 36864
2001:10f:60:7ff::9:b4 1.2.30.127 PSID 40960
2001:10f:60:7ff::a:b4 1.2.30.127 PSID 45056
2001:10f:60:7ff::b:b4 1.2.30.127 PSID 49152
2001:10f:60:7ff::c:b4 1.2.30.127 PSID 53248
2001:10f:60:7ff::d:b4 1.2.30.127 PSID 57344
2001:10f:60:7ff::e:b4 1.2.30.127 PSID 61440

Cheers,
Ian

From: Wojciech Dec <wdec.ietf@gmail.com<mailto:wdec.ietf@gmail.com>>
Date: Tuesday, 3 June 2014 12:39
To: Ole Troan <ot@cisco.com<mailto:ot@cisco.com>>
Cc: Tom Taylor <tom.taylor.stds@gmail.com<mailto:tom.taylor.stds@gmail.com>>, Ian Farrer <ianfarrer@gmx.com<mailto:ianfarrer@gmx.com>>, "draft-ietf-softwire-lw4over6@tools.ietf.org<mailto:draft-ietf-softwire-lw4over6@tools.ietf.org>" <draft-ietf-softwire-lw4over6@tools.ietf.org<mailto:draft-ietf-softwire-lw4over6@tools.ietf.org>>, Yong Cui <cuiyong@tsinghua.edu.cn<mailto:cuiyong@tsinghua.edu.cn>>, Softwires WG <softwires@ietf.org<mailto:softwires@ietf.org>>
Subject: Re: [Softwires] draft-ietf-softwire-lw4over6 excluding Well Known Ports
Resent-To: Ian Farrer <ian.farrer@telekom.de<mailto:ian.farrer@telekom.de>>, Mohamed Boucadair <mohamed.boucadair@orange.com<mailto:mohamed.boucadair@orange.com>>, <sunqiong@ctbri.com.cn<mailto:sunqiong@ctbri.com.cn>>, <tena@huawei.com<mailto:tena@huawei.com>>, <yiu_lee@cable.comcast.com<mailto:yiu_lee@cable.comcast.com>>, <yong@csnet1.cs.tsinghua.edu.cn<mailto:yong@csnet1.cs.tsinghua.edu.cn>>

How so, could you give an example?

On 3 June 2014 12:17, Ole Troan <ot@cisco.com<mailto:ot@cisco.com>> wrote:
Wojciech,

> Thanks. I'm not sure I get your example though. To exclude ports 0-1023, the excluded port "subnet" would be 0x0000/6. Which would be equivalent to a=6...

sorry, yes, you'd not assign 0000/6.
that's not equivalent to a=6 though.

cheers,
Ole

>
>
>
>
>
>
> On 3 June 2014 11:31, Ole Troan <ot@cisco.com<mailto:ot@cisco.com>> wrote:
> Wojciech,
>
> > Could you show a working example of that in action, along with the set of PSIDs containing the usable port ranges?
>
> in LW46, ports are provisioned per client. so, I don't understand what you want a working example of. that's just like assigning 192.168.0.10 - 192.168.0.255 in a DHCP pool. in the PSID case you will not assign ports 0000/10
>
> cheers,
> Ole
>
>
> >
> > Cheers
> >
> >
> >
> >
> > On 3 June 2014 10:51, Ole Troan <ot@cisco.com<mailto:ot@cisco.com>> wrote:
> > Woj,
> >
> > in the LW46 case, you can still do a=0, and ensure that you don't provision any PSID which results in the well known ports.
> >
> > cheers,
> > Ole
> >
> > >
> > > On 2 June 2014 21:49, Tom Taylor <tom.taylor.stds@gmail.com<mailto:tom.taylor.stds@gmail.com>> wrote:
> > > There's a difference between setting a=6 and setting aside the lowest PSIDs because they occupy that port space. The value of a determines how ports are assigned to each PSID, but does not affect the usable PSID numbering space.
> > >
> > > I think that you should illustrate how you think this would work before we reach a conclusion.
> > > A setting of a=6 arrives precisely at what the goal is here, exclude ports 0-1024. So if there is a need to have another way of achieving that, by creating some excluded magic PSID value that corresponds to 0-1024, we would like to know why is that relevant and how it is supposed to work in a system where the PSID conveys to the CE the port-range.
> > >
> > > Regards.
> > >
> > >
> > > RECOMMENDED is part of the RFC 2119 boilerplate. The (unintentionally) missing term is NOT RECOMMENDED.
> > >
> > > Tom
> > >
> > >
> > > On 02/06/2014 3:27 PM, Wojciech Dec wrote:
> > > Well, I'm referring to the "RECOMMENDED" part. If the recommendation is NOT
> > > to allocate ports 0-1024, then this effectively recommends that a-bits=6.
> > > Moreover the meaning of SHOULD vs RECOMMEND should be questioned. The
> > > latter is not a regular normative term, and arguably if the recommendation
> > > is for excluding 0-1024 then a=6 looks like the SHOULD. If anyone wants the
> > > full port set, then a=0 would be an obvious consequence.
> > >
> > >
> > > On 2 June 2014 19:50, Tom Taylor <tom.taylor.stds@gmail.com<mailto:tom.taylor.stds@gmail.com>> wrote:
> > >
> > > Not sure how you read that, but it can be fixed by putting a comma after
> > > "SHOULD be 0" and replacing "to allocate" with "thus allocating".
> > >
> > > Tom
> > >
> > >
> > > On 02/06/2014 12:14 PM, Wojciech Dec wrote:
> > >
> > > Uhm, this appears to mean that the RECOMMENDED a-bits SHOULD be 6.
> > >
> > >
> > > On 26 May 2014 13:24, Ian Farrer <ianfarrer@gmx.com<mailto:ianfarrer@gmx.com>> wrote:
> > >
> > >   Hi,
> > >
> > > This one slipped my mind….
> > >
> > >   From a discussion with Ole during the MAP dhcp last call, there was a
> > > discussion about the exclusion of provisioning WKPs to CPEs -
> > > http://www.ietf.org/mail-archive/web/softwires/current/msg06010.html
> > >
> > > In previous versions, the lw4o6 used to reference
> > > sun-dhc-port-set-option,
> > > which also stated that the WKPs should not be assigned. This advice got
> > > lost when changing to reference map-dhcp for PSID format.
> > >
> > > Here’s a wording change proposal to resolve this:
> > >
> > > Section 5.1
> > >
> > > Original text (last sentence, para 7):
> > >
> > > "For lw4o6, the  number of a-bits SHOULD be 0."
> > >
> > > Proposed change:
> > >
> > > "For lw4o6, the number of a-bits SHOULD be 0 to allocate a single
> > > contiguous port set to each lwB4.
> > >
> > > Unless a lwB4 is being allocated a full IPv4 address, it is RECOMMENDED
> > > that PSIDs containing the well-known ports (0-1023) are not allocated to
> > > lwB4s.”
> > >
> > > Please let me know if you are OK with the proposed change.
> > >
> > > cheers,
> > > Ian
> > >
> > >
> > >   Good spot on the WKP exclusion. Before the lw4o6 draft was updated to
> > >
> > > reference map-dhcp for configuration,  the port configuration was
> > > described
> > > in sun-dhc-port-set-option, which also stated that the WKPs should not be
> > > assigned. This advice got lost when changing to reference map-dhcp. I’ll
> > > make a suggested text update for the lw4o6 draft to fix this. Does that
> > > work for you?
> > >
> > >
> > > yes, that would be good.
> > >
> > > cheers,
> > > Ole
> > >
> > >
> > > _______________________________________________
> > > Softwires mailing list
> > > Softwires@ietf.org<mailto:Softwires@ietf.org>
> > > https://www.ietf.org/mailman/listinfo/softwires
> > >
> > >
> > >
> > >
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> > > https://www.ietf.org/mailman/listinfo/softwires
> > >
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> > >
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