[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RE: Switching Capability of Photonic Links with Transponder



Hi Greg, hi Wataru,

                             That is exactly what I had in mind with my e-mail.  I think we need to differentiate ‘colored’ from ‘colorless’ interfaces in routing protocol.

 

Moreover we should also think about the fact that an interface that is able to change the lambda (f I’ve understood your definition are the ones called ‘colorless’) can do that in two different ways:

 

1)       OEO that means there is also regeneration of the signal

2)       Using non linear effect that means there is no regeneration of the signal.

 

IMHO it is also important to advertise this kind of information.

 

BR


Diego

 

 

 

From: Greg Bernstein [mailto:gregb@grotto-networking.com]
Sent: lunedì 9 luglio 2007 18.32
To: Wataru Imajuku
Cc: Diego Caviglia (GA/ERI); MEURIC Julien RD-CORE-LAN; ccamp@ops.ietf.org
Subject: Re: Switching Capability of Photonic Links with Transponder

 

Hi all, concur with Wataru's comments.  If you check out some of the optical sub-system/component vendors you'll see ROADMs and switches that are "colored" and "colorless".  "Colored" meaning that a wavelength ingress on one port gets mapped to a particular egress port.  "Colorless" meaning that we can map an ingress wavelength on one port to an egress port irrespective of color.

Hence it seems we've got some problem area "modeling" work. Then we can see about potential representations/solutions.

Regards

Greg B.

Wataru Imajuku wrote:

Hi, Diego and Julien
 
 "OEO transponder that can only perform frequency switching lambda1 lambda 2."
 
 I think this device should be advertised as lambda switch capable, if the optical signals sent 
from this transponder are directily connectied to WDM networks (such as ROADM ring or transparent OXCs).
 
 But, it is not problem this interface is advertised as fiber switch capable,
 if the optical signal send from the transponder is terminated by electrical reciever in next hop node.
 
 Perhaps, if we properly incorporate this case into the GMPLS frame work, I think 
we need the concept of "colored TE-link" and "colorless TE-link" even to GMPLS control plane.
 In colorled TE-Link, the switching capability in both end take care the color of optical signal
even even if number of optical signal in the colered TE-link is unity.
 
 I think we need updated drafts describing photonic networks with consideration of recent progress of 
optical transport technologies.
 
 
  
         Hmmmmmm not sure my Understanding of the lambda switching is what Ie called spatial switching that is lambda1 portA lambda1 portB what is not clear to me is how can be advertised an OEO transponder that can only perform frequency switching lambda1 lambda 2.
    
 
 
 
At 15:39 07/07/05, Diego Caviglia (GA/ERI) wrote:
 
  
Hi Julien,
 
         Hmmmmmm not sure my Understanding of the lambda switching is what Ie called spatial switching that is lambda1 portA lambda1 portB what is not clear to me is how can be advertised an OEO transponder that can only perform frequency switching lambda1 lambda 2.
 
Adrian? Deb? Anyone else?
 
BR
 
Diego
 
-----Original Message-----
From: MEURIC Julien RD-CORE-LAN [<mailto:julien.meuric@orange-ftgroup.com>mailto:julien.meuric@orange-ftgroup.com]
Sent: mercoled4 luglio 2007 18.47
To: Diego Caviglia (GA/ERI); ccamp@ops.ietf.org
Subject: RE: Switching Capability of Photonic Links with Transponder
 
Hi Diego.
 
I believe we should refer to the Holly RFC 3945, chapter 1, verse 2:
 
- "Lambda Switch Capable" interfaces "can operate at the level of an *individual wavelength*" [or a "group of wavelengths"], meaning that you manipulate values of wavelengths (as AU-4 numbers [or AU-4 ranges] from an SDH portA to SDH portB), like in a ROADM;
 
- "Fiber-Switch Capable" interfaces "can operate at the level of a single or multiple *fibers*", meaning *spatial switching* where you don't consider the type of signal that ports convey (could be anything like a black and white signal, a wavelength, a WDM multiplex, some optical packets...), like in a OOO PXC.
 
To stick with strict terminolgy: lambda = wavelength = (speedOfLight / frequency)
 
So if you need to do "frequency switching", then it is the so called "lambda switching". :-)
 
Anyway, this is my understanding, so if I'm wrong or if it's a vocabulary issue because you find that terms are inappropriate, then we'd better ask father Adrian and sister Deborah.
 
Cheers,
 
Julien
 
-----Original Message-----
 
From: Diego Caviglia (GA/ERI) [<mailto:diego.caviglia@ericsson.com>mailto:diego.caviglia@ericsson.com] 
 
Hi Julien,
 
         Actually not the PXC I had in mind is able to switch a single lambda I didn't but the mux/demux In the picture sorry.
 
The point I failed to illustrate is the ambiguity of the term "Lambda Switch Capable" given that there two possible ways to switch a lambda.  
 
The first one is the spatial one: (Lambda1 portA) --> (Lambda1 portB) this is the way an all optical switch works and this why there is the lambda continuity constraint in photonic networks.  
 
The second one is the frequency switching: (Lambda1 portA) --> (Lambda2 portA) this switching can be done via a transponder (OEO) device.  
 
Of course is possible to mix the two switching having (Lambda1 portA) --> (Lambda2 portB)
 
My impression is that the definition "Lambda Switch Capable" refers to the spatial switching and thus I don't know how to model the fact that after/before a photonic matrix I have a transponder.  
 
I hope I've made my question clearer.
 
Best Regards
 
Diego
 
-----Original Message-----
 
From: MEURIC Julien RD-CORE-LAN [<mailto:julien.meuric@orange-ftgroup.com>mailto:julien.meuric@orange-ftgroup.com] 
 
Sent: marted3 luglio 2007 19.21
 
To: Diego Caviglia (GA/ERI); ccamp@ops.ietf.org
 
Subject: RE: Switching Capability of Photonic Links with Transponder
 
Hi Diego.
 
If I understand correctly, your "lambda switch" by itself is a PXC that
 
has only "Fiber-Switch Capable" interfaces. Then, you add
 
lambda-conversion cards to it. So, correct me if I'm wrong (you or
 
anyone else), but whether you do a lambda conversion inside a card or in
 
a core matrix, this new interface on your global device is able to work
 
on lambdas anyway  [(lambda 1, port A) --> (lambda2, port B)]. As a
 
result, you need to advertise your most flexible capability, which is
 
"Lambda Switch Capable".
 
If you used "FSC", you wouldn't be able to control your "lambda
 
swapping" card, as LSPs are like lists of fibers and labels aren't
 
wavelengths but ports.
 
But maybe I didn't get your actual issue.
 
My 2 cents,
 
Julien
 
________________________________
 
From: owner-ccamp@ops.ietf.org [<mailto:owner-ccamp@ops.ietf.org>mailto:owner-ccamp@ops.ietf.org] On
 
Behalf Of Diego Caviglia (GA/ERI)
 
Hi all,
 
        I've a doubt about how to model the following situation.
 
 
 
 
 
 
 
     +-----------------+
 
     |                 |-------+
 
     |                 | OEO   |
 
     |     Lambda      |-------+
 
     |     Switch      |
 
     |                 |
 
     |                 |
 
     +-----------------+
 
     
 
 
 
The node itself is able to cross connect only the Lambda while the
 
interface has a OEO transponder that is able to change the lambda
 
frequency.  In this case there are two different 'switching capability'
 
the spatial one that is performed by the switch (lambda 1, port A) -->
 
(lambda1, port B) and the frequency switching is done by the OEO
 
transponder.  Witch kind of interface switching capability I have to
 
advertise?
 
 
 
BR
 
Diego
 
 
 
Diego Caviglia
 
Product Line ON BBN
 
PA Broadband BNET
 
 
 
Marconi S.p.A
 
Ericsson Global Product Center - Italy
 
Via Anagnina,203
 
0018, Roma , Italy
 
www.ericsson.com <<http://www.ericsson.com/>http://www.ericsson.com/> 
 
 
 
Office:  +39 010 600 3736
 
Fax: +39 010 600 3493
 
Mobile: +39 335 7181762
 
Email: diego.caviglia@ericsson.com  
 
This communication is confidential and intended solely for the
 
addressee(s). Any unauthorized review, use, disclosure or distribution
 
is prohibited. If you believe this message has been sent to you in
 
error, please notify the sender by replying to this transmission and
 
delete the message without disclosing it. Thank you.
 
E-mail including attachments is susceptible to data corruption,
 
interception, unauthorized amendment, tampering and viruses, and we only
 
send and receive emails on the basis that we are not liable for any such
 
corruption, interception, amendment, tampering or viruses or any
 
consequences thereof.
 
 
    
 
-------------------------------------
Wataru Imajuku@NTT Network Innovation Labs
TEL: +81-46-859-4315
FAX: +81-46-859-5541
 
 
 
 
  



-- 
===================================================
Dr Greg Bernstein, Grotto Networking (510) 573-2237