Regional Network Future Architectures Joint Techs July 20,2004 TFN/OARnet

Legacy Networks Provisioned Circuits Many built in the mid to late 90s ATM based Looking for a convergence of services –Ip, voice video ATM originally was faster than alternatives Attempted to implement telco like signaling UNI etc. Used pseudo circuit switching. Could run virtual over lay networks as separate entities.

Motivations for Dark Fiber Network –Reduce long term costs It appears that long term costs can be contained by making large upfront capital investment –Allow dedicated light paths through regional fabric Research community believes that Lambda based service provides resource that other mechanisms don’t e.g. enhance research environment. –Allow interaction with other Gigapops and entities in a dedicated fashion

Motivations for Dark Fiber Network (continued) Provide better service by having total control. A belief that we now control our destiny –Sounds good but is it true? –What about whims of state budgets?

Conflicting Requirements Build new network to save money –Often cited as an incentive Build network to support on demand High Capacity Circuit (Lambda) Switching –Some progress in “tunable” devices but it still requires deploying amps, DCU to support under utilized infrastructure Allow for new collaborations e.g. be all things to all people

Conflicting Requirements (Continued) States have invested Millions Higher Ed has driven it, but there is pressure to add “equity partners” Desire to converge different types of data and networks –Ip, Voice, Video, ATM, RPR etc. –Sound familiar?

What will drive Architecture is Policy as well as Technology Political, Social, and Economics will drive as much as technical requirements Belief that Lambda switching will prevail is not very real because of economics in the short term Major investment to benefit the few. In Higher Ed research grants might be used to finance early work. Since the shared resource must be scheduled it will require many users with non-conflicting temporal needs at a minimum.

Analogy Current notions of schedulablity are much like operators manually plugging patch chords to complete circuit

Reality Check What are we doing? Alternatives such as MPLS, HOPI are much more realistic in the short term DWDM will drive convergence of various state entities to share same fiber plant The trick will be –How involve other communities and get them to pay fair share while…. –Higher Ed stays in the drivers seat

Future Architectures DWDM shared infrastructure in the short term Longer Term, Lambda (circuit switching) will be real when –1. Cost comes down to deploy fully provisioned infrastructure –2. Switching and demand patterns can be modeled using Erlanger like statistical analysis, e.g. an optical switch that is almost a “Phone switch” in time scale for switching (Microseconds) and utilization is predictable enough to allow scalable over provisioning