Subject: RE: DNS discovery

From: <[email-masked]>
Date: Thu, 13 Nov 2003 01:33:09 +0200

Hi,

> adding DHCP for 
> DNS configuration is exactly that: adding another protocol. 
> This is bad 
> because there is now an additional mechanism that can fail 
> and there is 
> additional delay in configuring.

I agree in this.

I'd like to point out that any additional (round trip) delay in configuration phase, especially in wireless (cellular) environments, is _not_ user friendly. Please consider those 200.000.000+ million cellular users opening a network link for browsing etc. purposes who have to wait every time for yet another round trip just because of DNS server address configuration, which could be obtained faster.. The collective amount of consumer time spend for DNS configuration could become large quickly, as wireless (cellular) devices tend to open connections often for short periods of time.

Quick example: 100ms extra time spend in every GPRS PDP context opening. 200.000.000 users open 1 PDP context per day for one year: 0.1s*200.000.000*365days = 84490 days = 231 years per every year spent on waiting for server configurations that could be done faster.. In this example. Numbers are estimates, extra time can be bigger, user number more or less.. But this should give some figures. Please correct me if I'm fundamentally mistaken.

Additionally if users pay for their connection per every transmitted byte those extra messages cost extra money..

Regards,

   Teemu

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From: Jim Reid <[email-masked]>
Date: Thu, 13 Nov 2003 00:44:29 +0000

>>>>> "teemu" ==   <[email-masked]> writes:

    teemu> I'd like to point out that any additional (round trip)
    teemu> delay in configuration phase, especially in wireless
    teemu> (cellular) environments, is _not_ user friendly. Please
    teemu> consider those 200.000.000+ million cellular users opening
    teemu> a network link for browsing etc. purposes who have to wait
    teemu> every time for yet another round trip .....

While I agree that minimising delays and RTTs is always desirable,
your argument is a bit of a non-sequitur. There's usually a delay of
10-15 seconds after a mobile phone is powered on or roams from its
home provider before it has finished the authentication dance and
joined some mobile operator's network. Given that context, an extra
RTT to find a DNS server is no big deal in the overall scheme of
things. In fact I suspect that the name server location overhead could
readily be assimilated into the "authenticate this handset" overhead.
Hey, perhaps getting a valid DNS server address could *be* that handset
authentication. 
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From: Masataka Ohta <[email-masked]>
Date: Thu, 13 Nov 2003 13:59:35 +0900

Jim Reid wrote:

> joined some mobile operator's network.

Just FYI, we developped a protocol over 802.11 WLAN with defact
standard psuedo adhoc mode to perform, with three-way handshake,
everything, including beaconing, mutual authentication between an
access point and a mobile node, sharing session key and address
assignment, which is a lot better than 802.1x requiring several
exchanges of packets.

We observed it work with 802.11 WLAN on mobile hosts moving at
260Km/h, for which 10-15 seconds are prohibitive.

						Masataka Ohta

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From: SHIRASAKI Yasuhiro <[email-masked]>
Date: Fri, 14 Nov 2003 04:15:22 +0900 (JST)

> Additionally if users pay for their connection per every transmitted byte those extra messages cost extra money..

So, if packet size of all periodical RA is increased by DNS option,
you will charge extra money for that?

--
SHIRASAKI Yasuhiro @ NTT Communications
t: +81-3-6800-3262, f: +81-3-5365-2990
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From: Mans Nilsson <[email-masked]>
Date: Fri, 14 Nov 2003 10:56:33 +0100

> you will charge extra money for that?

Isn't this true of all volume billing? Also, this is off-topic. 

-- 
Måns Nilsson         Systems Specialist
+46 70 681 7204         KTHNOC
                        MN1334-RIPE

Now I'm having INSIPID THOUGHTS about the beautiful, round wives of
HOLLYWOOD MOVIE MOGULS encased in PLEXIGLASS CARS and being approached
by SMALL BOYS selling FRUIT ...

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From: SHIRASAKI Yasuhiro <[email-masked]>
Date: Sat, 15 Nov 2003 00:29:00 +0900 (JST)

On Fri, 14 Nov 2003 10:56:33 +0100,
> Isn't this true of all volume billing? Also, this is off-topic. 

I agree. I meant that there is no obvious difference between candidates
from this point of view.

--
SHIRASAKI Yasuhiro