Building an Optical Regional Flexible Transmission Platform · Flexible Transmission Platform ......
Transcript of Building an Optical Regional Flexible Transmission Platform · Flexible Transmission Platform ......
Building an Optical Regional Flexible Transmission Platform
Anthony RyanTim Robinson 09-Apr-2008
Building an Optical Regional Flexible Transmission Platform
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NNW Flexible Transmission Platform•
Getting Hold of the Fibre
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Scenario 1 Research sites CWDM•
Scenario 2 Local Data Centres CWDM
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Scenario 3 Adding DWDM•
Summary
NNW Flexible Transmission Platform
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Part of NNW SJ5 Exploitation Plan•
Build e-Science Network
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Replace Telco GigE links with Dark Fibre•
Telco costs go down (no equipment) with move from GigE to Dark Fibre but costs tend to go up
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Dark fibre is still much cheaper than multiple GigE or 10 Gbps links
Who was asking for all these new links and extra bandwidth ?•
driven by e-science projects
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separation from production traffic•
dedicated bandwidth across the region
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usually to reach a UKLight or JLPS circuit at Manchester (JANET entry point for NNW)
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or part of a regional research network•
or just “free”
bandwidth across a campus
WDM ?•
different λ
simultaneously on same fibre
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optical signals from separate devices are assigned to different specific wavelengths.-
the specific wavelengths are multiplexed
together and injected into a single shared fibre.
CWDM v DWDM•
CWDM–
large channel spacing
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less channels but cheaper components–
lasers don’t need cooling
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filters can be less accurate •
DWDM–
channels crammed tighter -
more channels
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more expensive filters, lasers
Building an Optical Regional Flexible Transmission Platform
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NNW Flexible Transmission Platform•
Getting Hold of the Fibre
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Scenario 1 Research sites CWDM•
Scenario 2 Local Data Centres CWDM
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Scenario 3 Adding DWDM•
Summary
Getting Hold of the Fibre
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G-MING used dark fibre since 1995•
NNW has had short range dark fibre since 1997
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Discussions with Telcos since 2005 about long distance dark fibre–
THUS
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NTL:Telewest•
Telcos understand what NNW is trying to achieve and why
Getting Hold of the Fibre
Major Problems•
Diverse Routing
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Distances
Spring 2008 -
Schematic
Summer 2008 -
Schematic
Getting Hold of the Fibre
Major Problems•
Diverse Routing
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Distances
Summer 2008
Getting Hold of the Fibre
Major Problems•
Diverse Routing
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Distances
Getting Hold of the Fibre
Major Problems•
Diverse Routing
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Distances
Manchester –
Liverpool•
Point to point
48 km
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On fibre
101 km
Getting Hold of the Fibre
Major Problems•
Diverse Routing
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Distances
Preston –
Liverpool•
Point to point
44 km
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On fibre
126 km
Getting Hold of the Fibre
Major Problems•
Diverse Routing
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Distances
Manchester –
Jodrell•
Point to point
26 km
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On fibre
79 km
Lighting the Fibre
Use Transmode CWDM and DWDM equipment
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Transmode were keen to come and do trials
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And to do a demo of the kit •
and offer sale or return
Building an Optical Regional Flexible Transmission Platform
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NNW Flexible Transmission Platform•
Getting Hold of the Fibre
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Scenario 1 Research sites CWDM•
Scenario 2 Local Data Centres CWDM
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Scenario 3 Adding DWDM•
Summary
First Scenario: Jodrell Bank Observatory
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eVLBI -
a lot of telescope data to shift •
already had a 155 Mbps link for production
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needed extra capacity•
they obtained some new SM dark fibre (one pair) from Global Crossing
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wanted to get 2 x 1 GbE links out of it •
maybe more later
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this was a pretty simple arrangement
First Scenario: Jodrell Bank Observatory
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we didn’t even need an optical mux•
just plugged the fibre directly into the LINE (WAN) interface of a card at each site –
operating at 1510nm
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hence no mux needed because 1510nm was the only wavelength on the line
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linecards convert this and present it as 850nm•
presented to end systems as multimode
First Scenario: Jodrell Bank Observatory
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Jodrell Bank link required cards which could drive 80 km
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the 80km receivers will work with a signal as low as -28db
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we are receiving at about -26 db •
pretty close to lower limit but it worked without any problem
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JBO could begin to test sharing data…•
we implemented a similar arrangement on the Daresbury-Manchester and Daresbury to Liverpool links
Building an Optical Regional Flexible Transmission Platform
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NNW Flexible Transmission Platform•
Getting Hold of the Fibre
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Scenario 1 Research sites CWDM•
Scenario 2 Local Data Centres CWDM
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Scenario 3 Adding DWDM•
Summary
Second Scenario Linking Two Data Centres
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requirement for GigE and fibrechannel •
had some SM dark fibre locally between two datacentres
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talked to Transmode again•
they asked about the fibre we had
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gave us a few choices•
explained some future possibilities
Second Scenario Linking Two Data Centres
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so we came to initial design•
Transmode TS 1100 chassis with flexible choices of CWDM card combinations
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links could be set as GbE or Fibrechannel•
up to 16 wavelengths –
we use 6 of them
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an optical multiplexor to split up and recombine the CWDM wavelengths
Second Scenario Linking Two Data Centres
•simple enough –
no amplifiers needed•modules arrived set to appropriate assortment of wavelengths•just put the appropriate modules in each card•then connect each card to the matching port on the optical mux
Second Scenario Linking Two Data Centres
•nothing to configure on some cards•other cards you just set the protocol eg fibrechannel, GbE or STM•each card then spits out normal 850nm towards your end devices•so we got 5 fibrechannel links and 2 x 1 GbE across a single pair•it pretty much worked out of the box –
no tuning or configuration
Second Scenario Linking Two Data Centres
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Even the lowest spec card drives up to 40 km so 2km was easily covered
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2 km of fibre plus a couple of patches provides enough attenuation
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The 40km receivers will work with a signal as low as -20db or as high a 0db
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We are receiving at about -6db so no problem – it just works
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We have spare capacity to use the extra channels –
just add extra cards
Building an Optical Regional Flexible Transmission Platform
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NNW Flexible Transmission Platform•
Getting Hold of the Fibre
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Scenario 1 Research sites CWDM•
Scenario 2 Local Data Centres CWDM
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Scenario 3 Adding DWDM•
Summary
Third Scenario Adding DWDM for 10 gig
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We had used the same simple CWDM arrangement for Daresbury and Jodrell Bank i.e. we had provided 2x1GbE using simple CWDM-
DL: one for production/one for a regional
(North West Grid project) to Manchester and to Liverpool-
JB: two for research telescope data
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Two extra requirements came up…
Third Scenario Adding DWDM for 10 gig
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JANET(UK): “we can deliver 10 gig from Frankfurt to Manchester…can you deliver it to Daresbury ?”
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JANET(UK): “we can deliver 4 gig from Onsala to Manchester…can you drop that off in Jodrell Bank ?”
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So we explored how to get 10 gig across our existing links
Third Scenario Adding DWDM for 10 gig
DWDM C-band
CWDMOutsideDWDM-band
Mixing DWDM and CWDM Wavelengths
You can mix the two - as long as you leave some space!
In our case we had been advised to avoid 1550nm for CWDM since that covers the C-band which is a popular choice for DWDM. This made things easier when we came to add DWDM
But there are alternative combinations (of CWDM and DWDM bands)……as long as you have left appropriate space somewhere
CWDM OutsideDWDM-band
1 2 45 6 7 8
Third Scenario Adding DWDM for 10 gig
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got a bit more interesting as we got into mixing CWDM and DWDM on same fibre
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needed Amplifiers, Dispersion Control, OADM•
ended up with two sets of chassis
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added some extra gig links with CWDM too
Third Scenario Adding DWDM for 10 gig
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the add/drop multiplexer is the thing which lets you mix CWDM/DWDM wavelengths
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it strips off certain wavelengths for you•
lets you pass those to your CWDM cards
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and passes everything else to your DWDM kit
Third Scenario Adding DWDM for 10 gig
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What all this kit does…
Third Scenario Adding DWDM for 10 gig
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Normal signal arrives, say, at 850nm
Third Scenario Adding DWDM for 10 gig
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Signal gets converted to a specific DWDM wavelength
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1550.12nm in our case
Third Scenario Adding DWDM for 10 gig
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This filter combines DWDM wavelengths•
We only use one at the moment
Third Scenario Adding DWDM for 10 gig
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Our single DWDM wavelength carries on
Third Scenario Adding DWDM for 10 gig
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Signals get amplified for their journey •
The optimum level depends on how many channels you see yourself using in future
Third Scenario Adding DWDM for 10 gig
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DWDM signals mixed with CWDM here•
Note we only had to amplify the DWDM
Third Scenario Adding DWDM for 10 gig
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Signals travel across link•
Power will be dropping on the way
Third Scenario Adding DWDM for 10 gig
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Add/drop multiplexer does its job•
Peels off our specific CWDM wavelengths
Third Scenario Adding DWDM for 10 gig
Third Scenario Adding DWDM for 10 gig
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We needed amplifiers before and after the long distance links
Third Scenario Adding DWDM for 10 gig
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We also needed dispersion control modules due to the long distance
Third Scenario Adding DWDM for 10 gig
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If we used more than one DWDM wavelength they would be split up by this filter
Third Scenario Adding DWDM for 10 gig
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Reaches the receiver –
hopefully at a nice comfortable level after being amplified twice while suffering attenuation on way
Third Scenario Adding DWDM for 10 gig
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Signal presented to end systems
Building an Optical Regional Flexible Transmission Platform
•
NNW Flexible Transmission Platform•
Getting Hold of the Fibre
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Scenario 1 Research sites CWDM•
Scenario 2 Local Data Centres CWDM
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Scenario 3 Adding DWDM•
Summary
NNW e-Science Network
ManchesterKilburnDaresbury Daresbury
Liverpool
2 * 1 Gbps 2 * 1 Gbps2 * 1 Gbps
1 Gbps
1 * 10 Gbps
Jodrell
ManchesterReynolds
1 * 10 Gbps
4 * 1 Gbps
Summary
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If using CWDM, try to keep some space in case you choose to add DWDM later
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Most common for DWDM is C-band but there are S or L bands you could reserve instead
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Keep telco fibre records –
helps at design•
find out how your UKLIGHT circuits are to be presented –
avoid unnecessary LH/SH type
media conversion•
Need optical meters to commission and test
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New hardware maintenance requirement
Futures•
Procurement of kit for production network
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N * 10 Gbps on NNW ‘diamond’•
Liverpool –
Preston –
Manchester –
Stoke
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Liverpool•
N=2, 4?
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Use MPLS instead of n * 1 Gbps for lower speed links?
NNW e-Science Network
ManchesterKilburnDaresbury Daresbury
Jodrell
2 * 10 Gbps
2 * 10 Gbps
2 * 10 Gbps
2 * 10 GbpsLiverpool ManchesterReynolds
2 * 10 Gbps