Subject: Review of RFC2303/2304

From: Claudio Allocchio +39 040 3758523 <[email-masked]>
Date: Tue, 2 Mar 1999 18:23:24 +0100

> Keith had wanted further work done to clarify wording, make some English
> improvements, etc.   
> If you want, I could put aside some time early in the IETF week to go over
> the RFC 2303/4 text with you and whoever else you might want to review it.

Ok James: anybody willing to contribute to the update please contact 
either James or myself.

I would also like to collect information about the current implementation 
status of "standard addressing" format. As far as I know Lotus presented 
a conformant product within their "unified messaging solution". Also 
"Ford Motor Co." requested their software vendor to develop a conformant 
solution (including the extensions of full addressing mode) for their 
internal global messaging service. 

Is there any other implementation around?

As many of the implementation which currently claim conformance to the 
I-fax model still do not support a standard addressing method, I think it 
is worthwhile a short summary of real life implementation scenario. In 
fact is it very important to understand that only supporting also 
standard addressing a product can correctly interwork in large scale and 
open environment.

Let's consider first the I-fax native devices. 

In a "close" environment, i.e. where there is a closed community using fax
over the Internet (a few identical I-fax devices only) the e-mail
transport service (MTAs) can interwork with any non standard addressing,
as they all recognise the same LHS syntax. More over only a restricted
number of users are authorized to use the I-fax devices, and they can be
easily authorized on any of the I-fax devices. 

A "totally open" environment, on the other hand, in unlikely to happen 
also on the Internet: in fact in such a case economical constraints (like 
subcription fees, authorizations, repudial of third party traffic, etc.) 
will probaly anyhow make impossible the open use of any I-fax device 
available on the Internet.

A more realistic "open" scenario is composed of a collection of "closed" 
or "partially closed" island, each one with its own "authorized users", 
all interconnected together to exchange "unified messages" (like fax, 
voice, ...). It is likely that inside single islands simiar or identical 
I-fax devices can use non standard addressing mode. However this will 
make impossible the deployment of the global open service. Here is an 
example of problems which will be generated if non standard addressing is 
used.

"User A" and "User B" belong to "island 1", where addressing is 
[email-masked]
They are authorized to use "island 1" devices, only. 

"User C" belongs to "island 2", where addressing is
[email-masked]
He is authorized to use "island 2" devices, only.

"User D" belongs to "island 3", where addressing is
[email-masked]
She is authorized to use "island 3" and "island 2" devices, only.

Now, "User A" sends a message to "User B", "User C" and "User D", where
non-standard-X(User Y) is the GSTN Fax address of "User Y" written using 
non standard syntax accepted in "island X":

From: non-standard-1(User A)@island1-device.domain1
To: non-standard-1(User B)@island1-device.domain1,
    non-standard-1(User C)@island1-device.domain1,
    non-standard-1(User D)@island1-device.domain1

At this point, "User B" can reply without problems to anybody, while "User
C" and "User D" cannot use "island 1" devices (because they have no
authorization to do so). Thus they cannot reply.

Let's, however, imagine that the I-fax devices in "island 3" and "island 3"
and User Interface are clever, and thus they totally hide the e-mail
routing section of the addresses. However these devices in "island 2" and
"island 3" do not understand "non-standard-1" syntax. As a consequence 
"User C" and "User D" again cannot reply.

Whichever other combiation of "sender" and "recipients" you create in 
such a situation, there will always be sombody which cannot reply correctly.

The situation is identical to the one existing with e-mail gateways. In 
this case it is maybe worse: in fact, if the recipient is on the e-mail 
service, he will see the complete e-mail addresses (see above), and no 
User Agent will hide the e-mail routing section. Only in case the LHS of 
the address uses standard syntax, a User Agent will be able to recognise 
the particular situation, and knowing that there can be "autohrization" 
problems, the it can "locally rewrite" the address in order to use a 
local e-mail to fax gateway where the local user is authorized.

More over, using "non global-phone" syntax is such cases can create the 
same kind of interoperability problems. However a "non global-phone" but 
standard address can be recognised by a device or gateway and the user 
can be advised accordingly.

I hope the above explanation is ehough to make anybody understand that 
implementation not conforming to standard addressing (minimal or 
extended) will create very serious interoperability problems to their 
users, and, IMHO, thi is enough not to "blu stamp" as "Internet Standard 
Conformat" an implementation.

Ok, I wanted to "ping" implementors a bit, and thus, please fill free 
to re-distribute this message as you like.

:-)

regards
Claudio

---

From: [email-masked]
Date: Tue, 2 Mar 99 23:50:46 +0000

Forwarded Message:
> To: James Rafferty <[email-masked]>
> From: Claudio Allocchio +39 040 3758523 <[email-masked]>
> Subject: Review of RFC2303/2304
> Date: Tue, 2 Mar 1999 18:23:24 +0100
> -----
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:-)

regards
Claudio

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