Statewide Communications

One of the major accomplishments in FY01/02 was the design and initial implementation of a CISN communications infrastructure. Doug Neuhauser of the BSL took the lead in investigating options and the CISN partners decided to establish a ``ring" of T1 communication links (Figure 4.1) with dual routers at each node.

As described last year, the CISN ring is up and operational. It is being used to transmit seismic waveform data and parametric data, including strong motion parameters, between the management centers and to distribute ShakeMaps to OES. It is also used to support mirroring of the CISN Web server.

During 2003-2004, the CISN performed a test to verify the failover and redundancy capabilities of the CISN ring. The goals of the test were to 1) verify that if a single segment of the CISN ring fails, the backbone routers will detect the outage in a timely fashion and will reroute traffic to all CISN sites around the remaining CISN ring segments, and 2) verify that if a site is completely disconnected from the CISN ring, the backbone routers will detect the outage in a timely fashion and will reroute traffic to/from that site over the backup Internet tunnels between the disconnected site and all other CISN sites.

The test conducted demonstrated that the CISN routers and ring are performing according to design. However, the CISN OES routers do NOT have public Internet connections yet, so they have no Internet tunnel connections. If the CISN T1 circuits were to go down at OES, OES would be completely isolated from the CISN network and all CISN partners. This continues to be an issue of major concern.

During the last year, the BSL began the process to upgrade the Cisco IOS (Internetworking Operating System) installed on the routers, only to discover that additional memory was required in order to support the latest version. The BSL ordered memory for all the routers, sent the needed modules to Caltech, CGS, and USGS Menlo Park, and installed memory on the BSL and OES routers. As of the end of June, the only CGS routers were waiting for the upgrade to be completed. When all the memory is installed, then the BSL plans to begin testing the new IOS (which supports ssh and scp), prior to rolling it out on all the routers. Once the new IOS is fully deployed, then CISN will perform another test of the ring.

Figure 4.1: Map showing the geographical distribution of the CISN partners and centers. The communications ``ring" is shown schematically with installed links (solid lines).
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Figure 4.2: Map showing the 30 stations selected to send data directly to the Northern and Southern California processing centers, and the 5 stations that send data directly to the Engineering Data Center and the Southern California processing center.
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Berkeley Seismological Laboratory
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