tailieunhanh - IP over WDM network

Outline: History of WDM networks. Current Internet: Multilayer protocol stack between IP and WDM layers. Future: IP directly over WDM Challenge: Virtual Topology Reconfiguration, Multilayer routing, One proposal: Optical Burst Switching technologies. | IP over WDM network Fang Yu 294 Class Presentation Outline History of WDM networks Current Internet: Multi-layer protocol stack between IP and WDM layers Future: IP directly over WDM Challenge Virtual Topology Reconfiguration Multi-layer routing One proposal: Optical Burst Switching technologies History In the late 70s First fiber based optical transmission system Before 1995 Mostly a single high-speed optical channel All multiplexing done in electrical domain(TDM) 50Mb/s to 10Gb/s data services After 1995 WDM allows simultaneously transmitting multiple high-speed channels on different frequencies (Up to 160 wavelengths today) 40G per l (OC768) Total link capacity = 160 l *40G = Tbps Current Typical Protocol Stacks IP ATM SONET WDM WDM Proprietary (20-400 Gb/s) OTS OTS OTS OTS OTS OTS (OTS: Optical Transport System) Transport Layer Model “Packet” “Packet” “Packet” “Packet” 1/0 DCS 1/0 DCS 1/0 DCS 1/0 DCS 4E 4E 4E 4E 3/1 DCS 3/1 DCS 3/1 DCS 3/1 DCS 3/3 DCS Layer (DACS III) DACS III | IP over WDM network Fang Yu 294 Class Presentation Outline History of WDM networks Current Internet: Multi-layer protocol stack between IP and WDM layers Future: IP directly over WDM Challenge Virtual Topology Reconfiguration Multi-layer routing One proposal: Optical Burst Switching technologies History In the late 70s First fiber based optical transmission system Before 1995 Mostly a single high-speed optical channel All multiplexing done in electrical domain(TDM) 50Mb/s to 10Gb/s data services After 1995 WDM allows simultaneously transmitting multiple high-speed channels on different frequencies (Up to 160 wavelengths today) 40G per l (OC768) Total link capacity = 160 l *40G = Tbps Current Typical Protocol Stacks IP ATM SONET WDM WDM Proprietary (20-400 Gb/s) OTS OTS OTS OTS OTS OTS (OTS: Optical Transport System) Transport Layer Model “Packet” “Packet” “Packet” “Packet” 1/0 DCS 1/0 DCS 1/0 DCS 1/0 DCS 4E 4E 4E 4E 3/1 DCS 3/1 DCS 3/1 DCS 3/1 DCS 3/3 DCS Layer (DACS III) DACS III DACS III DACS III DACS III ATM/IP ATM/IP ATM/IP ATM/IP DS1 ( Mb/s) DS3 (45 Mb/s) DS3 (45 Mb/s) OC48+ ( Gb/s) ADM ADM ADM ADM ADM ADM ADM Fiber Conduit/ Sheath 3/1 DCS Layer SONET ADM Layer Core ATM/IP Layers Service Layers Media Layer LA CHCG LA LA LA LA LA LA PHNX PHNX PHNX CHCG CHCG CHCG CHCG CHCG Wavelength Path Crossconnect Wavelength Mux Section Crossconnect Hard- Wired Disadvantage of Current Multi-layer Protocol Stack Inefficient In IP over ATM over SONET over WDM network, 22% bandwidth used for protocol overhead Layers often do not work in concert Every layer now runs at its own speed. So, low speed devices cannot fill the wavelength bandwidth. When detecting of failure, different layers compete for protection Optical layer detects failure almost immediately, restores error in 2us to 60ms SONET layer detects failure in –100 us, restores error in 60 ms Disadvantage of Current Multi-layer Protocol Stack (Cont) Functional overlap: So many layers are doing the same thing

• Quản trị mạng
• IP over WDM network
• History of WDM networks
• Current Internet
• Virtual Topology Reconfiguration
• Multilayer routing