Re: Proposed response to the Liaison Statement on LMP Link Verification

[Jonathan Sadler <jonathan.sadler@tellabs.com>]

I see the discussion as being broken down as follows:
- What should be sent in-band to identify a CP-link
- What could be sent out-of-band to identify a CP-link
  (through trace correlation)

G.7714.1 deals only with the in-band approach.  lmp-test-sonet-sdh
deals with both approaches.

The out-of-band case handled by lmp-test-sonet-sdh is out of scope
for G.7714.1 -- what two consenting systems, management or otherwise,
exchange across their DCNs is out of scope for G.7714.1.

The liaison from T1X1 asked if it is necessary for two totally
independent message formats to exist for the in-band case as the
function being performed by both G.7714.1 and the Jx Test Message
Connetivity Verification approach defined in lmp-test-sonet-sdh is
the same.

Only the in-band issue needs to be discussed.

Jonathan Sadler

PS. I couldn't help but respond to Deborah's attempt to clarify:

"Brungard, Deborah A, ALABS" wrote:
> db: Note, to clarify, G7714.1 requires all new G7714.1-aware
> transport equipment, both terminations and intermediate equipment.

This is untrue.  The G.7714.1 formats are consistant with the
capability required in G.707, making hardware changes unnecessary.
The design of the message format was done with remoting of the
Discovery Agent in mind -- allowing for non-G.7714.1-aware transport
equipment to be a part of an overall system that does indeed use
G.7714.1 formats.

Compare this with the intrusive Jx Test Message formats defined
by lmp-test-sonet-sdh.  The behavior of a legacy element that
recieves this non-printable string is unknown, let alone how to
configure (using TL1) the TTI to be validated by a NIM.

> And for operators, "turning-off" of legacy intermediate NIMs is not
> an option (proposed in G7714.1),

G.7714.1 also states that how the message formats defined in
G.7714.1 interact with functions such as NIM is for future study as
turning off these functions may not be necessary.

Indeed, turning off NIM is unnecessary if the NIM is using
a G.7714.1 message format for the TTI.

> as the investment in intermediate NIMs is not for 24/7
> entertainment of our field staff.  G7714.1 does not "peacefully
> coexist".

Nor do the intrusive Jx Test Message formats defined by
draft-ietf-ccamp-lmp-test-sonet-sdh.  Further, it is impossible
to provision the resulting non-printable string to be used for
the TTI making these formats impossible to use with legacy NIMs.

> One ITU operator suggested using a different byte than Jx based
> on this concern with G7714.1.
>
> Whereas, LMP requires GMPLS-aware transport equipment.

I'm not certain if this is a benefit as the intrusive Jx Test
Message formats defined by lmp-test-sonet-sdh restrict the
deployment of GMPLS to only new equipment.  Use of a byte other
than Jx for this function yields the same situation.

Given the amount of SONET/SDH equipment already deployed, the
business models necessary for Telcos to be profitable, and the
current CAPEX spending environment, limiting GMPLS to new
equipment deployments will not aid in the rapid deployment of
GMPLS.

However, if the protocols allow for the GMPLS control plane to
be external from a LEGACY element, there is a better chance for
rapid GMPLS deployment.

> And LMP provides two options depending on support by legacy
> equipment (in-band, correlation).

Two comments:

1) Only in-band signals can guarantee the proper identification
  of a CP-link.
2) The correlation method defined by lmp-test-sonet-sdh is not
  precluded by G.7714.1 -- what two consenting systems exchange
  across their DCNs is out of scope for G.7714.1

> For either G7714.1 or GMPLS LMP, an operator chooses equipment
> configurations/options based on their application.  New
> applications/new equipment (no free lunch;-)).

Incorrect assertion -- see above.

> No different from today's operations. And the two options
> (in-band, correlated) provided by LMP support two different
> use scenarios, including use of legacy NIMs. As discussed
> for G7714.1, Q9 needs to evaluate the equipment support
> scenarios.



============================================================
The information contained in this message may be privileged 
and confidential and protected from disclosure.  If the 
reader of this message is not the intended recipient, or an 
employee or agent responsible for delivering this message to 
the intended recipient, you are hereby notified that any 
reproduction, dissemination or distribution of this 
communication is strictly prohibited. If you have received 
this communication in error, please notify us immediately by 
replying to the message and deleting it from your computer.

Thank you.
Tellabs
============================================================