NREN Dark Fibre: CWDM Implementation & Networking Experience

1. NREN on dark fibre with CWDM - experience of S&M Zoran Jovanović, Belgrade University Computer Centre – RCUB ANW Moldova

2. Deregulation • Telekom Srbija – monopoly until June 2005 • Telekom Srbija is (almost) the only owner of intercity fibers • Telekom Srbija does not lease dark fiber • Expensive high capacity digital links • New owners are appearing: Power company, Oil company, Railway, … • Cable TV operators in towns

3. Year 2002 • SinSEE Project: Donation of German ministry for science and technology in active networking equipment. • Fiber lines established: • RCUB-Rectors office (5km) • RCUB-Novi Sad (95 km – 23dB attenuation) • RCUB-Vinca (15km) • All lines installed and working

4. Awareness – ceremony with PM • Intercity dark fiber was given only for testing • GBIC ZX were for Vinca institute – used for intercity connection • Video conferencing of the minister with other university centers • Service at the operator didn’t exist – pricing? • Strategic approach – to include the new optical infrastructure that is appearing

5. Year 2003 – Signed • Contract with Telekom Srbija – Q3 of 2003 • Novi Sad – Subotica (130 km) • Beograd – Kragujevac (130 km) • Beograd – Niš – Gigabit Ethernet over SDH (250 km) • Lines are now being finally tested • 8 locations in Belgrade • 3 locations in Novi Sad • 2 locations in Kragujevac • 4 locations in Niš

6. Key problems in implementation • Getting building permissions for dark fiber layout to the university, high school or institute buildings • Winter without digging • Testing by the operator • The only customer with this service • Buildings of the operator should be avoided for telehousing by laying out a optical cable to the nearest school or institute – example Belgrade - Kragujevac

7. Year 2004 - signed • Annex of the contract with Telekom Srbija • Phase 1: • Subotica – Szeged! (40 km) - SEEREN • Phase 2: • Novi Sad – Zrenjanin • Beograd – Šabac (90 km) • Beograd – Valjevo (90km) • Valjevo – Užice (89 km) • Užice – Čačak (58 km) • Čačak – Kraljevo (33 km) • Kraljevo – Kruševac (83 km) • Kruševac – Niš (84 km) • 3 locations in Belgrade

8. Year 2004 - Signed • Annex of the contract with Telekom Srbija • Phase 3: • Beograd - Pančevo (20 km) • Kraljevo – Novi Pazar (91 km) • Niš – Pirot (71 km) • Niš – Leskovac (46 km) • Leskovac – Vranje (68 km) • Niš – Bor (130 km) • Novi Sad – Sombor (72 km) • 7 new locations in Belgrade

9. Subotica NREN of NREN of Sombor Serbia Serbia and and Szeged / Hungarnet SEEREN/GEANT Zrenjanin Montenegro Montenegro N OVI SAD Local ISP Pančevo Telekom Nodes : B EOGRAD Srbija Šabac National N OC Core Nodes Valjevo V. Plana Bor Athens / GrNet Gbps nodes SEEREN/GEANT Kragujevac International: Kraljevo Užice 1Gbps/100Mbps Čačak Kruševac 34 Mbps N I Š Pirot Internal : Novi Leskovac 2 *1 Gbps Eth ernet Pazar 1 Gbps Eth ernet Vranje Podgorica 1 Gbps Eth /SDH 2 Mbps EuroPACS 2004 UChHIS and Telemedicine

10. Locations in Belgrade

11. University hospitals on the NREN • GE MAN that will connect most advanced hospitals in Belgrade • In Serbia, all medical faculties will have a 1Gbps connection • More than 30 buildings of the campus of the Medical faculty and Dentistry faculty in Belgrade will have 1Gps connections by the end of 2004 – Medical campus – laying cables along the heating pipes

12. Equipment and technologies • Gigabit Ethernet • Low cost interfaces • Use of low cost L2 or L3 switches • Sufficient at the moment in Serbian NREN • Use of CWDM • Planning to use of optical amplifiers

13. NS Cisco 3550 BG Cisco 6509 CWDM test – July/August 2003 • Cisco CWDM test kit • Replaced 1000BaseZX • Belgrade – Novi Sad (95 km – 23dB att.) • 4 Gbps Etherchannel 1470 nm, 1510 nm, 1550 nm, 1590 nm CWDM MUX-4 CWDM MUX-4

14. Total attenuation • Telekom Srbija has G.652 fibers • Total attenuation approx: 23dB+3dB+4dB = 30dB • CWDM 1000BaseZX optical budget: 30dB • Problems expected on 1470 nm • 45 days without any carrier transition

15. CWDM experiment conclusions • Can be used on intercity lines for up to 100km • Reliable solution, • Low cost solution • Easy bandwidth upgrade • Great flexibility for different logical topologies

16. CWDM Problems • Optical amplification: • EDFA cover narrow wavelength range (typically C-Band or L-Band). In CWDM will be used for a single lambda, when a lambda is dropped, amplified and added. • LOA – Cover broader wavelength range. At the moment of our analysis were available only as product evaluation kits. Noisy, low amplification, narrow bandwith. • Experimental OA for the whole range - Japan

17. Our solution • Majority intercity links are shorter then 100km – daisy-chained • If needed - OEO conversion using L3 switches • Replacing the OEO conversion with EDFA OA to reduce RTT • Drawbacks – in totally Ethernet network – relatively slow convergence, added delay • Idea: Justify the use of dark fiber through fast and cheap connection provisioning. Later find the best solution for the network

18. Potential Belgrade – Novi Sad – Subotica - Hungary connection

19. Strategy • Using CWDM until there is a request for higher bandwidth • Try to establish our own intercity optical infrastructure North – South backbone with G.655 cables – combining with e-government • Use fiber of other dark fiber suppliers – fault tolerance • Establish DWDM if we don’t get our own fiber • Establish a SEE backbone for NRENs

20. Conclusion • Widespread use of inter- and intra-city dark fiber is the main direction in which Serbian NREN is moving • Cross-border dark fiber connections in SEE region are the next step for inter-NREN connections • CWDM with 1 GE is a reliable technology which the Serbian NREN will most probably use in the near future

21. Thank you for your attention Questions ANW Moldova