Distributed Restoration

DPAS Network Control System (DNCS)
This is my personal favorite. It was a Systems Engineering and Technical Assessment (SETA) project under a government funded contract. This project started in December 1988 and proceeded through September/October 1990 and involved a team from HO and MV. Our BL government contact Supervisor was John Waninski and the team consisted of Systems Engineers from HO: Ahmet Arslan (1988-89), Jim Bobeck (1988-90); and Software gurus from MV (1989-90): Dave McDonald, Jeff Gerrish, and Dave Priebe.

Unfortunately, almost all of my electronic versions of documents are no longer in my possession.

I do have one Distributed Restoration performance benchmark here: DNCS Performance Benchmark from DSL (.ps 17 Kb)
And I have one Operations Plan (what the Military would have to re-consider) which contains a small overview section on the algorithm

here:

If you find this information interesting, you may get paper copies from published documents in Linus/ITIS (what used to be the Iternal Technical Document Service - ITDS). You may get paper copies of these by requesting them via Linus/ITIS.

dn 54612-901211-01IM ; ti DNCS Test-Bed Demonstration Report. ;au Bobeck, JD ;lo HO Pages: 162

kw self-healing; restoration; distributed; network

ab The DPAS Network Control System (DNCS) Test-bed is a four node fully connected network of DACS IIs and colocated control processors (DNCP). Each

DACS II has six DS1 level transmission facilities connected to other DACS IIs in the network, two between each pair of DACS IIs. Each DNCP communicates

with only its immediate neighbor (adjacent) DNCPs via a point-to-point X.25 connection carried on the DACS II network. This document contains summary performance statistics when the Test-bed was used to restore service to DSO-level circuits on the network which were disrupted under seven network damage scenarios. da 12/11/1990

dn 54612-891019-03IM ;ti DNCS Real-Time Distributed Simulator: Statistical Design of Wartime Scenario Exercising. ; au Bobeck, JD ; lo HO Pages: 9
ab The DPAS Network Control System (DNCS) is a distributed control system which provides a restoration service for high priority circuits carried on a DACS II network. Under major network damage, the DNCS can autonomously find alternate routes for service-disrupted circuits from the remaining network resources using a distributed restoration algorithm. In 1989 AT&T Bell Laboratories is building and exercising a four node Real-Time Distributed Simulator. The statistical design of the Simulator exercising evaluates the effects of two major factors of network damage on the circuit restoration performance and robustness of the
DNCS. The Timing factor is set at two levels: Single Attack and Sequential Attack. The Severity factor is set at three levels: 25%, 50%, and 75% of the simulated network facility resources are damaged. The Simulator exercising of the six wartime scenarios will be replicated three times each. da 10/19/1989

dn 54612-891006-01IM ;ti Self Healing and the DPAS Network Control System (DNCS): Distributed Restoration Algorithm Overview;au Bobeck, JD;lo HO Pages: 17
ab The DPAS Network Control System (DNCS) is a distributed DACS II network control system primarily designed for restoring service on circuits disrupted by catastrophic events in the network. By monitoring the state changes of the DACS II and ascertaining that the disruptions will last a significant amount of time, the DNCS executes the distributed routing algorithm. It uses Reconfiguration Circuit Control application layer messages to find low cost paths through the network and to restore service on the disrupted circuits. The distributed circuit control algorithm cycles through Monitor, Takedown, Search, and Connect phases. da 10/06/1989

This project netted 2 patents for
Ahmet, Dave, Jeff, and myself.