3 Introduction Lambda networking enables e-Science applications that require huge data transfer with QoS guarantee. Dedicated network channels called lambdas or lightpaths are created as a dedicated leased line without jitter and congestion. Lightpaths are provisioned by control plane while traffics travel through data plane.
4 Control Plane and Data Plane Control plane chooses and reserves a deterministic, bandwidth-guaranteed path for a given connection request. routing + signaling messages are passed through "control channel" over physical topology Data plane is separated from control plane in order to speed up forwarding. network is now viewed as a collection of "lightpaths" Virtual topology is depicted by connecting lightpaths and routers in between
5 A B C D E Control plane (routing + signaling) Optical Transport Network Physical topology Data Plane (forwarding only) virtual topology P Q X Y
6 Management Plane The Emergence of Management Plane Although functions of routing, signaling and forwarding are fulfilled by control plane and data plane, we still need some management functions such as resource/bandwidth maintenance, failure notification and lightpath survivability… etc. Physical Layer Optical Layer (SDH,DWDM…) Control Plane Data Plane
7 Functions of Management Plane Virtual topology visualization Lightpath resources and bandwidth management SDH channels and DWDM wavelengths Alarm Notification and Error Indication Trap analysis Lightpath survivability Protection and restoration Performance measurement and monitoring Re-route the LP if the performance falls below a certain level
8 Lightpath Survivability In general, lightpath survivability is achieved by protection. fast switching time (<50ms) Protection by carrier extra cost Protection by SONET/SDH In the absence of failure, the protected bandwidths are wasted To improve bandwidth utilization, restoration by re- routing the failed lightpath dynamically is another way to achieve survivability.
9 Lightpath Restoration Not every lightpath is eligible for restoration. A rational business model: only those requiring QoS guarantee are candidates for restoration Exact location of error is determined through root-cause analysis of traps in order to choose the candidate LPs for restoration. For each restorable LP, the re-route path can be either statically stored in a given table or dynamically calculated. Intra-domain restoration vs. inter-domain restoration
10 TWAREN / TAIWANLight Lambda Testbed Taipei Hsinchu Taichung Tainan NTU NSYSU NCKU CCU NCNU NCHU NTHU NCTU NCU Sinica NTUStarLightCANARIE CANARIE Pacific Wave MAN LAN 3*STM-4+2*STM-1 3*STM-4+3*STM-1 2.5G 2G 1.25G 1.8G 2.5G Pacific Wave South
11 Distribution of TW-US Lightpaths TN TN TP SFC SEATTLE LA STARLIGHT NY Chicago Taipei TW-US lightpaths Layout
12 TN TN TP SFC SEATTLE LA STARLIGHT NY Chicago Taipei Initial LP provisioning from TN to NY Tainan to NYC: under normal operation
13 TN TN TP SFC SEATTLE LA STARLIGHT NY Chicago Taipei A failure occurs on the unprotected LA-NY link Event 1: LA NYC fails
14 TN TN TP SFC SEATTLE LA STARLIGHT NY Chicago Taipei The affected TN-NY LP is dynamically re-routed Event 2: re-route kicks off
15 Inter-Domain Operation (1) TN TN TP SFC SEATTLE LA STARLIGHT NY Chicago Taipei A LP is provisioned from TN to an interdomain site A A
16 Inter-Domain Operation (2) TN TN TP SFC SEATTLE LA STARLIGHT NY Chicago Taipei A Node NY failed
17 Inter-Domain Operation (3) TN TN TP SFC SEATTLE LA STARLIGHT NY Chicago Taipei A TN-NY LP is re-routed as TN-STARLIGHT
18 Inter-Domain Operation (4) TN TN TP SFC SEATTLE LA STARLIGHT NY Chicago Taipei A The peer domain re-routes their LP to STARLIGHT
20 Applications Lambda Testbeds Network automation can be achieved with management plane. Optical Exchanges The optical exchange administrators have to monitor the connectivity and the exchange sites may have to participate in inter-domain operations if the clients are connected without O/E/O conversion. Global Collaborations
21 Conclusions Lambda networks connect e-Science applications across different continents with service level guarantee. We need a way to monitor the status of the virtual topology provisioned over lambda networks. In this paper, elements of optical management plane are discussed.