Subject: [dhcwg] sub-option vs. encoding field

From: Soohong Daniel Park <[email-masked]>
Date: Fri, 03 Feb 2006 09:21:40 +0900

Hi DHC folks,

I'd like to clarify what is the most preferable from the DHC WG
point of view either sub-option or encoding field based on the
link below; 
http://www1.ietf.org/mail-archive/web/dhcwg/current/msg05828.html

Let me revise a draft following our opinion before Dallas meeting.

Thanks, 

Daniel (Soohong Daniel Park)
Mobile Convergence Laboratory, SAMSUNG Electronics.

_______________________________________________
dhcwg mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/dhcwg

---

From: Andre Kostur <[email-masked]>
Date: Thu, 02 Feb 2006 16:57:48 -0800

Soohong Daniel Park wrote:
> Let me revise a draft following our opinion before Dallas meeting

Offhand I'd prefer sub-options.  It would probably make it easier for 
other applications as well (such as LAN sniffers).  Although one 
drawback for the referenced draft is that if you are passing a list of 
URIs, RFC 3396 doesn't apply to sub-options, only to complete options 
(it's less likely that a list of FQDNs, or IPs, will exceed 255 bytes).

---

From: Ted Lemon <[email-masked]>
Date: Thu, 2 Feb 2006 18:23:33 -0700

> point of view either sub-option or encoding field based on the

I can't speak for the group as a whole, obviously, but I agree completely with 
David Hankins on this one - it's never a good idea to use an encoding flag in 
a DHCP option, so if you have to support multiple encodings, use suboptions, 
or just separate options.   But if you can, don't use multiple encodings.

---

From: Ted Lemon <[email-masked]>
Date: Thu, 2 Feb 2006 18:26:42 -0700

On Thursday 02 February 2006 17:57, Andre Kostur wrote:
> Although one

In general, if your URI is longer than 255 bytes, it doesn't belong in a DHCP 
packet.   We've actually had this discussion before, with respect to another 
URI encapsulation option.   The problem is that you may be tempted to include 
a ton of data in a URI because, well, you can.   But what you should really 
do is just have a short URI that maps to the longer URI.   That way you're 
using a TCP-based protocol to get the longer URI, not DHCP, and you don't 
suffer from packet size limitations.

---

From: Andre Kostur <[email-masked]>
Date: Thu, 02 Feb 2006 17:34:15 -0800

> suffer from packet size limitations.
I was more referring to the _list_ of URIs exceeding 255, not a single URI.

---

From: Ted Lemon <[email-masked]>
Date: Thu, 2 Feb 2006 18:46:33 -0700

> I was more referring to the _list_ of URIs exceeding 255, not a single URI.

Blech.   I missed that part.   Honestly, stuffing a list of URIs that long 
into a DHCP packet still seems like a really bad idea.

Daniel, can you tell us what you would normally expect to see as a list of 
URIs?

---

From: Soohong Daniel Park <[email-masked]>
Date: Fri, 03 Feb 2006 10:55:50 +0900

Thanks Ted and Andre for your comments. While revising a draft, I am saying 
that the IP address information would be the most preferable sub-option. In
terms of URI, it just means IEEE802.21 Information Service Server URI. If
multiple Servers are deployed, URIs list may be required.

---

From: Soohong Daniel Park <[email-masked]>
Date: Mon, 13 Feb 2006 10:32:03 +0900

Following the comments, I've revised a draft with suboption format. 
http://www.ietf.org/internet-drafts/draft-daniel-dhc-mihis-opt-01.txt

Thanks your all comment on that.

---

From: "David W. Hankins" <[email-masked]>
Date: Mon, 13 Feb 2006 11:53:07 -0800

> http://www.ietf.org/internet-drafts/draft-daniel-dhc-mihis-opt-01.txt

I'd like to continue to encourage you to investigate if a single format
is acceptable (eg only the ip address or only the fqdn or only the uri).

Simple is better, no two ways about it.

Outside of that, I have no technical argument.

Couple editing nits; note that you used '1' as the suboption value in each
of the three examples ascii art, and you want to say that the length of the
third option "is variable", not "variables".

-- 
David W. Hankins		"If you don't do it right the first time,
Software Engineer			you'll just have to do it again."
Internet Systems Consortium, Inc.		-- Jack T. Hankins
_______________________________________________
dhcwg mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/dhcwg

---

From: Soohong Daniel Park <[email-masked]>
Date: Tue, 14 Feb 2006 10:40:57 +0900

>Simple is better, no two ways about it.

As I indicated in this document, a singla IP address suboption is the
most preferable to be used for this function. But I should take care
of others simultaneously since three methods (IP address, FQDN and
URI) are included into the IEEE802.21 specification.

>third option "is variable", not "variables".

modified.

Thanks,