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ESnet Circuit Infrastructure:

The circuit infrastructure for ESnet4 is based on an ESnet-Internet2 partnership in which

Internet2 has contracted with Level3 Communications for the dedicated use of a national optical

fiber footprint that provides the required rich topology of circuits (those marked "Level3" in

Figure 8 and Figure 9). The partnership entails ESnet participating in the design and cost sharing

for the new network. The deployed fiber is provisioned with Infinera optical multiplexing

equipment that provides multiple 10 Gb/s circuits that ESnet and Internet2 use independently to

build their respective networks

The Core Topology:

Organizing the circuits as a set of interconnected rings produces a cost-effective and reliable core.

ESnet has used this architecture successfully for the past five years to provide a core network

availability of greater than 99.99% and a site availability of 99.9% or greater. (For the past year

most of the large science Labs that are connected via MAN rings have experienced 99.99% -

99.999% availability.)

The Core Hubs:

The ESnet core hubs

are

located

in

telecom-grade

facilities  that  are

highly

secure,

provide

redundant

sources  of  power,

and provide remote

technician  services

for equipment repair.

The ESnet devices at

the core hubs consist

of

internally

redundant,

carrier-

class, IP routers and

switches.

These

devices  have  dual

processors,

power

Figure 8:ESnet Circuit Configuration December, 2007

supplies,  etc.,  that

allow  maintenance

without interrupting operation and automatic failover in the event of a component failure. In

addition, there is secure, out-of-band access to the routers for emergency engineering access.

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