GSFC's L-Net design is best described in three parts

• GSFC Local Network
• Regional Network
• Transcontinental Network

Each of these parts is summarized below
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GSFC Local Network Part (i.e., within GSFC)

The initial GSFC L-Net will have an inter-building 10-Gigabit Ethernet (GE) backbone implemented with 10-GE inter-connected Force10 E600 and E300 10-GE switches, which in turn will support 10-GE up/down links to Extreme Network Summit 400-48t 1-GE switches with up to two 10-GE up/down links to various computer, display, and/or storage area network clusters. It also will include up to four 1-GE connections with GSFC’s Science and Engineering Network.

The 10-GE connected clusters minimally will include:

• Thunderhead Beowulf compute cluster (512 CPUs): L-Net will connect two sets of 16 CPUs, each with their own 10-GE uplink to enable local tests of distributed cluster processing
• Tiled display cluster in Scientific Visualization Studio: either the existing 2x3, or the new 3x3, CPUs in the tiled display cluster
• Network test stations in, and inter-building connection between, GSFC’s High End Computer Network and EOSDIS Network Prototyping Lab
• Optical switch from UMBC/Ray Chen

Other GSFC-based computer, display, and/or storage area network clusters can be easily added as funding is available for the L-Net’s extension. A specific set of such extensions are described in Pat Gary’s FY05 proposal for IRAD funding (scrubbed of specific building info) ( 1.9 MB). These include:

• A parallel interface to GSFC's Storage Area Network Pilot
• NASA Center for Computational Sciences
• Other clusters such as the Land Information System (200 CPUs)

Others can be easily planned as the design of the L-Net is easily extendable.

Regional Network Part (i.e., between GSFC in Greenbelt, MD, & Level3 POP in McLean, VA)

In cooperation with the NSF-funded Dynamic Resource Allocation via GMPLS Optical Networks (DRAGON) Project (see Related Links), the L-Net Project is arranging to have 1 dedicated and 1 shared 10-GE link across the DRAGON network between a Force10 E600 10-GE switch at GSFC and a Force10 E300 10-GE switch that the L-Net Project will place in the Level3 POP at McLean. These two 10-GE links will ride over DRAGON’s Movaz-based dense wave division multiplexing (DWDM) infrastructure ( 40KB).

DRAGON, with partial funding from the L-Net Project, will lease colo space in the Level3 POP in McLean and a ring of fiber pairs from the Level3 POP to GWU to ISI-East to the Level3 POP. An overview diagram of the planned DRAGON network ( 44KB) is provided. An alternate overview diagram of the planned DRAGON network is provided. A map-overlaid overview diagram with inter-site-fiber-distance of the planned DRAGON network is provided.

In the Level3 POP, DRAGON will deploy a Movaz RAYexpress OADM; and GSFC will deploy its Force10 E300 10-GE switch plus a couple of PC-based network performance test workstations with 10-GE network interface cards (NICs), quad-GE NICs, and/or 1-GE NICs.

The first two PC workstations to be placed at McLean will be dual 3.06 GHz Intel Xeon processors with 1 GB of memory and 80 GB disks, running Red Hat Linux 8.0 and a 2.4.18 SMP Linux kernel. They each will have one Intel PRO/10GbE LR Server Adapter 10-GE NIC (capable of streaming 5 Gbps), one Intel PRO/1000 MT Quad Port Server Adapter quad-GE NIC (with each 1-GE interface capable of full 1-GE line rate), and one Intel PRO/1000 MT Server Adapter 1-GE NIC (capable of full 1-GE line rate). Each PC is capable of sustaining 5-Gbps network throughput (either via a single stream on its 10-GE interface or five streams across its five 1-GE interfaces); so the pair of PCs in tandem can fully saturate a 10-GE connection, either via two 5-Gbps streams or 10 (2*5) 1-Gbps streams.

Transcontinental Network Part (i.e., the NLR and the GSFC 10-GE switch and workstations in the Level3 POP in McLean, VA)

The NLR (see Related Links) has planned extensive Layer1/Physical network deployments ( 52KB) and an initial set of four network-wide 10-Gbps lambdas ( 48KB). Phase 1 deployment of NLR’s Layer1/Physical network was completed on 08/28/04.

• An overview diagram of Phase 1 ( 44KB) is provided
• A more detailed diagram of Phase 1 ( 48KB) is provided
• An overview diagram of the Layer 2/GE network (a.k.a. the 1-GE VLAN lambda) planned for one of NLR’s lambdas ( 52KB) is provided
• An overview diagram of the Layer 3/IP network (a.k.a. the 10-GE Shared IP lambda) planned for one of NLR’s lambdas ( 36KB) is provided
• The Internet2’s HOPI network (see Related Links) planned for one of NLR’s lambdas is still under development

The L-Net Project will arrange GSFC membership in the Mid-Atlantic Terascale Partnership (MATP) (see Related Links) through which GSFC will obtain rights as defined for Class A members to use the assets and services of the NLR, giving GSFC full rights to use the NLR's 10-GE Shared IP lambda and the 1-GE VLAN lambda.

An L-Net project Force10 E300 10-GE switch will be placed in the Level3 POP in McLean initially with two 10-GE LAN PHY ports for connecting with NLR lambdas, in addition to its 4 other 10-GE ports for connecting across DRAGON or with the network performance test workstations GSFC will place there. GSFC’s two 10-GE ports for NLR are planned initially for interfacing respectively with MATP's interface ( 44KB) and HOPI's interface ( 36KB) equipment; but temporarily at least one of these 10-GE ports could be used for an OptIPuter (see Related Links) interconnection.

An illustration providing an overview of the 10-Gbps connections between the computational, storage, visualization, and network test clusters at OptIPuter/UCSD, OptIPuter/UIC, and GSFC is provided.

A diagram ( 48KB) summarily illustrating the GSFC L-Net design is provided in the following figure