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List:       gnudip2-general
Subject:    [Fwd: Re: [GnuDIP] GnuDIP, MX Records and All That]
From:       Creighton MacDonnell <creighton () macdonnell ! ca>
Date:       2001-10-31 4:58:02
[Download RAW message or body]

I just realized this came straight to me.

I cannot figure out how to get MailMan to put a "Reply-To" for
the list in the E-mail it sends.

-------- Original Message --------
Subject: Re: [GnuDIP] GnuDIP, MX Records and All That
Date: Wed, 31 Oct 2001 11:31:08 +1100
From: Roger Buck <rog@saas.nsw.edu.au>
Organization: -= Studio of Arts And Sciences =-
To: Creighton MacDonnell <creighton@macdonnell.ca>
References: <3BDE07A5.6A3B96D@macdonnell.ca>
<3BDE5DF5.C0077E4D@saas.nsw.edu.au> <3BDEEB4A.4C65F96A@macdonnell.ca>

Creighton MacDonnell wrote:
> 
> > > Have you considered replacing this dial up intranet with a PPP over SSH
> > > VPN, which would use the internet? This would look the same to postfix
> > > as what you have now. Or you could keep your reliable dial up intranet
> > > and build a VPN too.
> >
> > Yes - This has been considered and is a good option _except_ that this
> > means we have to pay three times for the same traffic (our internet
> > costs are based on cost per Mbyte and is charged on both incoming and
> > outgoing traffic!). If we tunnel, then we pay for incoming to our tunnel
> > gateway + outgoing from our tunnel gateway + incoming to final tunnel
> > destination. On the other hand, if we can set up a virtual dynamic IP
> > network (Gnudip) then we can probably deliver more than 90% direct to
> > final destination.
> 
> I am confused by this. If you set up a VPN tunnel over a TCP connection,
> your ISP (at either end) will have no idea what is being sent over the
> connection (since you will encrypt it whatever method you use). They
> will
> of course charge you for the bandwidth usage, which will be slightly
> greater due to the "wrapping" around the tunnel.

we are not talking about the tunnel overhead - we are talking about a
300 percent cost markup. The way it works is this:

Someone from public internet sends 1M mail to dynamichost1.my.net - what
happens is:

1. MX record shows that primary mx for dynamichost1.my.net is
reliablehost.my.net


2. 1M email received by reliablehost.my.net - Cost say 13c

3. reliablehost.my.net relays (using some tunnel) to dynamichost1.my.net
- This outbound traffic is also charged - say 13c + 1c overhead = 14c
total.

4. The 1M + overhead now arrives at dynamichost1.my.net via tunnel
routed accross Internet - say new cost may round up to 14c

Total cost (to school system) for delivey of 1M data thus = 41c. Amazing
but true!

On the other hand, If we can set up Gnudip so that mail for
dynamichost1.my.net is always deliverd direct when that host is on-line
(more than 95% of time) then we only pay once.  

This setup would mostly only be used for email sent to out network from
public Internet... but the same considerations apply if mail is sent
from one school to another via the Internet... The sending school pays
for data transmitted and the receiving school pays again for that same
data when it is received. The cost to the school system is thus 2 x
cost!

I know I haven't explained this very well but hope it makes more sense
now?

[--snip--]

R.

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