1. Rob.Vietzke@uconn.edu Connecticut Education Network University of Connecticut NEREN The Current State and Future of Advanced Optical Networks July 20, 2004

2. Agenda Current State of the Optic Networking Metro Regional New Approaches & Hype Broken Reasoning Community Directions

3. Distance scales for U.S. R&E optical networking Distance scale (km) ExamplesEquipment Metro< 60 UWash USC/ISI(LA), MAX(DC/MD/VA) Dark fiber & end terminals (cwdm, routers, pluggables) State/ Regional< 500 I-WIRE (IL), I-LIGHT (IN), NEREN Optical Amplifiers, filters, etc. Extended Regional/ National > 500 TeraGrid 2 nd Gen Abilene, NLR Add OEO regenerators & O&M $’s

4. CT Ed Net “Metro” Experience Over 1,200 miles of SMF-28 fiber deployed across Connecticut 160 dark fiber connected K12, Higher Ed sites All edge sites are GigE  Higher Eds homed to 2 core sites  Up to 4 K12’s daisy chained between pair of core sites  Some CWDM for metro higher ed rings  Considering 10G/1G CWDM combo links

5. CEN Leased Dark Fiber Network

6. Current State: Metro Typical Scenarios for metro optics Long Haul GBIC, SFP, XFP, or Xenpak  Occasionally POS or ATM long haul on dark fiber Integrated pluggable in router/switch Redundancy through Link State monitoring on multiple paths and L3 routing Occasionally CWDM or even DWDM added Almost no other statusing other than up/down of optical layer Market leaders could do more …  Make basic power telemetry available from pluggables  Make cross-vendor pluggables usable  Encourage higher-power affordable single-channel applications By example 10G-ER+ to match 1G ZX

7. Current State: Metro CWDM Passive nature of OADM’s makes rings livable for customer sites in non-C/O environments  Dedicated, redundant GigE Paths from site  Maintains link state to core  Reasonable Cost / Performance CWDM OADM packaging adds complexity No cost effective test gear/approach for CWDM  Complexity of cabling, patching, testing, cleaning can’t be overstated. Still arguably a great, cheap, disruptive approach

8. CWDM OADM Options

9. CWDM GBIC & XenPack-ER One Fiber Pair LAMBDA XXXX OADM East Router Router Xenpak-ER West East East 1470nm West 1470nm Not Used Xenpak-ER West East East 1470nm West 1470nm Not Used CWDM-MUX-AD-1470 CWDM-MUX-AD-1470 Site A Site B 2 λ 1x GE 1x 10GE 1470 GBIC

10. Current State: Regional 3 rd Generation DWDM Systems Market competitors moving very much in step with one another  Planning tools  Power Management  ROADM (Reconfigurable Add/Drop Mux)  Other Evolutions Dynamic Optical power management across systems, paths, channels, bands Very manual OADM approaches  Disruptive insertion and balancing  Lots of patch cords within systems & even shelves??  Highly touted ROADM typically works with limited wavelength windows on transponders & mux-ponders

11. Current State: Regional 3 rd Gen DWDM (Cont’d) More Flexible transponders and muxponders  Larger agile frequency range for optical output  Larger variety of interfaces and better stuffing of 2.5G and 10G wrappers Device Management  Increasingly good telemetry and monitoring of optic power, bit error rate, etc.  May need to know TL-1 or CORBA  Always check on XML & SNMP options?  A whole new OSS to learn and support in many cases Very Much an analog world  Dispersion, loss, balancing, planning more about gain structure than bits.  Still wonder if a good sound engineer or a physicist would understands these things better than a bit head

12. DWDM OADM Site Block Diagram

13. Current State: Regional Analog World 99% of designs are fundamentally about how much “noise” can you allow to grow in a system before you won’t be able to see bits anymore and therefore need to regenerate Faster bit rates are harder to distinguish at shorter distances than slower bit rates

14. Disruptive Thought? OEO everywhere O-E-O Maximize distance between expensive transponders, muxes, etc Reduce “noise” by reducing OADM’s, amps, etc wherever possible Aggregate analog PM data, have some fault isolation capability Analog-Optical Systems Regenerate every analog wavelength at every site, make noise problems so far beyond span specs as to become irrelevant Leverage E in OEO to create electrical add-drop fabric at each site Digital Optical Network

15. That’s fine, but what would Next Generation Equipment that you wanted look like?

16. Needs & Future Directions Agile Amplification & Dispersion Approach  Not visit dependant as channel loading increases or fiber ages  Not even to patch an agile transponder in to the right ROADM port Interruption-free upgrades/changes Initially affordable & predictable scalability Allow multi-point exchange of lambdas  Not just rings! Spurs & Aliens necessary  Support RON interconnection Good growth cost curve (>? Distruptive ?)

17. Observations We’re spending lots of dollars on separate software licenses, maintenance contracts and O&M systems for optical and L3+ services Telemetry still lousy for the large enterprise Am I running a digital optical network or a broadband CATV system Composite Triple Beat, Carrier to Noise Ratio, Harmonics, Composite Second Order, etc. all things I remember from balancing amplifier cascades. (Telemetry for that stunk too.)

18. Current Approach: Assume optics and routers are separate Accept need to purchase/learn new O&M Look to roll wrappers in to transport layer  Increase complexity there too? Look for additional flexibility and features to be built in to –both- parts of the equation

19. Approach: OEO w/elec. fabric Still assume optics and routing is separate Essentially eliminate analog portion of the problem by doing full conversion and retiming to digital at each site Continues separation of Optic and Services hardware Provides switched “wavelengths” cheap 2.5G based cross fabric may create new barriers for wide-band migration to 40G and 100G Another highly complex device to understand, manage, troubleshoot and maintain Idea of a backbone electrical fabric probably increases opportunities for good multi-point junctions at high bandwidth Replace Line-Card router optics with this technology?

20. Approach: Purify, Simplify O & E Move digital timing, framing, shaping, etc. in to routers with controllable ITU grid wavelengths out (Large form pluggables?) Maybe even tunable wavelengths? Make optical portion pure optic amplification, Dispersion, balancing, etc. Eliminate shaping, timing, framing cards. Good telemetry and control back to routers for optic control Can I graph optical performance on Cricket/MRTG? Need dispersion compensation for 10G or eFEC at day0 Advance Alien Wavelengths in to Optic platforms Think about federated optical networks! Cannibalizes vendor business units & requires current business to do development together Single wavelength application can actually be router-only with no throw-aways as DWDM is added Probably still lousy at multi-directional fiber intersections

21. Other thoughts Drive vendors on telemetry from optics Anticipate we will need the ability to link RON’s, perhaps with (or even without) a common national backbone for all services We need to solve Alien Wavelength problem on optical & router platforms Need ability to monitor and control Power, Wavelength, dispersion, eFEC, etc across the common control plane Need standardization of signalling and wrappers for alien wavelengths

22. Rob.Vietzke@uconn.edu Connecticut Education Network University of Connecticut NEREN The Current State and Future of Advanced Optical Networks July 20, 2004