Subject: RE: [Isis-wg] Question on DCC Architecture

From: "Cypryan Klish" <[email-masked]>
Date: Mon, 18 Dec 2000 15:26:48 -0500

> OK, but the DCN is not the DCC.

Wrong.  This is a very common misunderstanding, however, the definitive
ITU-T recommendation states otherwise.

Specifically, ITU-T M.3010 (02/00) 11.2 states:

"The DCN may consist of a number of individual subnetworks of different
types, interconnected together.  The DCN may be a local path, or a wide area
connection among distributed functional blocks.  The DCN is technology
independent and may employ any single or combination of transmission
technologies."

Previous editions of M.3010 such as (05/96) contained a similar definition.
In fact, section 4.1.4. of M.3010 (05/96) stated:

"...The various types of subnetworks may include technology specific
subnetwork(s) such as the SDH DCC."

In other words the DCC is part of the DCN; the two are not separate.

SIF's Architecture Work Group found a need to clarify this further by
adapting the terms "access DCN" and "embedded DCN" per the proposal
contained in SIF-AR-9808-120; this became common usage in the final year of
that work group's activity (1999).

As to the scope of the SIF work, it addressed only an IP-based "Access DCN"
- the part of the DCN between an OSS and a GNE; see the approved document
SIF-033-1999 "Requirements for the TCP/IP Protocol Suite on the SONET Access
DCN."  This approved document does contain requirements (sections 7.5) for
FTP-based file transfers and for a FTP/FTAM translation device, so an
infrastructure for software download was put in place, so I don't know what
would be considered incomplete about software download support. In fact,
Annex C of SIF-033-1999 contains SIF's addional TL1 messages specific to
file transfer.  However, I don't know if anyone ever implemented these.

The SIF IP on the DCC activity was never completed, although some of the
contributions identified earlier in this thread are informative as to the
issues and discussions. However, note they are just contributions and not
approved solutions.

Kip Klish

-----Original Message-----
From: Mike Truskowski [mailto:[email-masked]]
Sent: Monday, December 18, 2000 11:08 AM
To: [email-masked]
Cc: [email-masked]; [email-masked]; [email-masked];
[email-masked]; [email-masked]; [email-masked]; [email-masked];
[email-masked]; [email-masked]; [email-masked]
Subject: Re: [Isis-wg] Question on DCC Architecture

OK, but the DCN is not the DCC.

The NSIF, formerly the SIF, worked on the mediation
issues dealing with OSI and TCP/IP.  The work was
incomplete since it dealt with datagrams and not
software download.   

Are you saying that the SG15 is working on mediation
in the DCN to include software download?  

Mike

> 
> Just to clarify a point...
> 
> The ITU-T SG15 Q14 has recently started work on a generic DCN
> architecture and there was agreement in the last experts meeting in Dec,
> 2000 that this DCN would be IP based and would address the issue of
> interworking between an OSI based DCN and IP based DCN.
> 
> Regards,
> Shiva
> 

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