Subject: Re: [pcp] Comments on draft-tsou-pcp-natcoord-08

From: "Reinaldo Penno (repenno)" <[email-masked]>
Date: Sat, 1 Dec 2012 14:49:33 +0000

On 11/30/12 8:58 AM, "Simon Perreault" <[email-masked]> wrote:

>Hi Reinaldo,
>
>Le 2012-11-28 14:47, Reinaldo Penno (repenno) a écrit :
>> In both 2 and 3 NAT could be performed by PCP controlled device. There
>>is
>> no discussion of this aspect (maybe due to Lw4o6 drivers) but if the
>> mechanism is to be generic, we need to define how it would work. As I
>> think about it , it seems there are quite a few issues to be ironed out.
>
>As mentioned in the presentation, there are ONLY TWO differences between
>MAP and MAP_PORT_SET:
>
>- MAP maps a single port, MAP_PORT_SET maps a set of ports. (Obviously!)
>
>- MAP_PORT_SET has the limitation that NAT is optionally applied to the
>address (as for MAP), but *never* applied to ports.
>
>If someone can find a way to make MAP_PORT_SET work with NAT applied to
>ports, please do suggest it.

A few comments here:

1 - MAP_PORT_SET delegates ports as opposed to installing a translation
port mapping. This is almost a firewall application and would be good if
it could be applied in that case as well. IN other words, allow a
application to open bulk ports in firewalls.

2 - A important distinction of MAP and MAP_PORT_SET is that MAP nails down
a single mapping port out of many that can continue to be used for
NAPT44/NAT64, etc. I believe this should still be possible. In other
words, create a 1:1 bulk mapping as I suggest below while leaving other
ports within the subscriber quota for regular NAT.

3 - Suggestion on MAP_PORT_SET applied to ports

Client sends a MAP_PORT_SET indicating its internal available range, say,
1024-2047 (1024 ports). The CPE certainly knows the internal range it has
available, there is no ambiguity here.

Server, allocates external ports 32000-32511 ports. Those 512 ports would
be mapped 1:1 into the internal ports beginning with the first one.

So,

32000<->1024
32001<->1025
Š
32511<->2047

4 - NAT could still be done for outbound 1:1 if host performs source port
control. So in this case MAP_PORT_SET could be used for NAPT in a SLNAT44
fashion as we discussed when CPE is in bridge mode.

Let me know your thoughts.

Thanks,

Reinaldo

>
>Agreed?
>
>Thanks,
>Simon
>-- 
>DTN made easy, lean, and smart --> http://postellation.viagenie.ca
>NAT64/DNS64 open-source        --> http://ecdysis.viagenie.ca
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---

From: Qiong <[email-masked]>
Date: Sun, 2 Dec 2012 21:44:26 +0800

Dear Reinaldo,

Thanks for your explaination. Below is my consideration.

On Sat, Dec 1, 2012 at 10:49 PM, Reinaldo Penno (repenno) <[email-masked]
> wrote:

> application to open bulk ports in firewalls.
[Qiong] I think this is fine:)

> ports within the subscriber quota for regular NAT.
[Qiong] I'm still a little confusing about this 1:1 bulk mapping.In 1:1
port mapping, if the CPE will not do NAPT, but just the CGN(PCP server)
will do the port mapping. Then, why does this CPE request MAP_PORT_SET?
Only to inform the PCP server with its internal port range ? I think in
most cases, the internal port range is a full range (0~65535), right ?

Best wishes
Qiong

-- 
==============================================
Qiong Sun
China Telecom Beijing Research Institude

Open source code:
lightweight 4over6: *http://sourceforge.net/projects/laft6/*
PCP-natcoord:* http://sourceforge.net/projects/pcpportsetdemo/ *
===============================================

---

From: "Reinaldo Penno (repenno)" <[email-masked]>
Date: Sun, 2 Dec 2012 14:46:51 +0000

From: Qiong <[email-masked]<mailto:[email-masked]>>
Date: Sun, 2 Dec 2012 21:44:26 +0800
To: Reinaldo Penno <[email-masked]<mailto:[email-masked]>>
Cc: Simon Perreault <[email-masked]<mailto:[email-masked]>>, "[email-masked]<mailto:[email-masked]>" <[email-masked]<mailto:[email-masked]>>
Subject: Re: [pcp] Comments on draft-tsou-pcp-natcoord-08

Dear Reinaldo,

On Sat, Dec 1, 2012 at 10:49 PM, Reinaldo Penno (repenno) <[email-masked]<mailto:[email-masked]>> wrote:
On 11/30/12 8:58 AM, "Simon Perreault" <[email-masked]<mailto:[email-masked]>> wrote:

A few comments here:

[Qiong] I'm still a little confusing about this 1:1 bulk mapping.In 1:1 port mapping, if the CPE will not do NAPT, but just the CGN(PCP server) will do the port mapping. Then, why does this CPE request MAP_PORT_SET? Only to inform the PCP server with its internal port range ? I think in most cases, the internal port range is a full range (0~65535), right ?

[Reinaldo] There are two use cases:

1 – Map a range of ports to a server/CPE. Certainly having one mapping is better than many individual ones
2 – There are cases where the range of ports restricted as described in SLNAT44 and other drafts.

Best wishes
Qiong

So,

32000<->1024
32001<->1025
Š
32511<->2047

Open source code:
lightweight 4over6: http://sourceforge.net/projects/laft6/
PCP-natcoord: http://sourceforge.net/projects/pcpportsetdemo/
===============================================

---

From: Qiong <[email-masked]>
Date: Mon, 3 Dec 2012 14:41:45 +0800

Dear Reinaldo,

Thanks for your suggestion. I think MAP_PORT_SET can be used in your
proposed use cases. We will update the draft to reflect this requirement.

Best wishes
Qiong

On Sun, Dec 2, 2012 at 10:46 PM, Reinaldo Penno (repenno) <[email-masked]

>
>
>   From: Qiong <[email-masked]>
> To: Reinaldo Penno <[email-masked]>
> Cc: Simon Perreault <[email-masked]>, "[email-masked]" <
> [email-masked]>
> On Sat, Dec 1, 2012 at 10:49 PM, Reinaldo Penno (repenno) <
> [email-masked]> wrote:
>

Open source code: