Minutes of Working Group Meeting

CFHT Base Facility, Waimea

September 12, 2002




Congratuations to Bernt Grundseth upon his retirement. We hope he will continue to come and join us whenever the meetings are held in his neighborhood.

  1. Current Network Status
  2. July 30th - several observatories reported slow connections to the Internet between 9:00am and 10:30am. Pui Hin was not able to determine for certain what the source of the problem was, but she has strong suspicions that it was the UH-ITS core router, which has been causing problems for the last several months.

    August 5th - brief interruptions were introduced between 1:30 and 2:00pm while the MKOCN Hilo router was reconfigured to make the UH-ITS Microwave OC3 our preferred Internet access route.

    August 16th to 22nd - a whole series of acceptance tests were performed by UH-ITS on the various segments of the OC3 microwave system. By reverting to the DS3 connection, we were not affected by these tests except for the 22nd when there was a loss of connection to the Internet for about 30 minutes. On this occasion, Pui Hin wanted to see if OSPF will pick an alternate route if a manual switch of preferred route is not performed.

    August 23rd - Pui Hin took advantage of another microwave system interruption to confirm what she observed the day before. An interruption of 15 minutes was introduced.

    Here is an explanation on why it failed: To prevent traffic not belonging to MKO from entering the DS3, some cost weighting is set at UH-ITS. On the MKOCN routers, default routes have to be set to force the traffic through the desired path. If a network failure occurs on a segment downstream from our direct connection, our default routes still prefer the failed route if the failed route normally has a lower cost than the alternate route. The problem will go away once we no longer depend on the Interisland DS3. At that time, we will remove all our default routes.

    September 3rd - brief interruptions were introduced by the upgrading of the MKOCN Hilo router between 1:30 and 2:00pm

    September 4th - longer interruptions were introduced by the upgrading of the MKOCN summit router between 11:00 and 2:00pm

    September 9th - failure of a 6500 switch at West Hawaii while we were troubleshooting our gigabit Ethernet link to UHH caused some confusion and interruptions between 2:00 and 3:15pm.

  3. Update on the various projects
  4. After thoroughly cleaning of all the fibers and connectors, inside and outside several times, optical loss on the fibers became stable. Of the 24 fibers, two strands remained unusable. Pui Hin decided to go ahead and accept the job since fixing the two fibers might cause damage to the other ones, and since we are unlikely to need all 24 strands.

    The new 7206VSR-NPE400 was shipped to the IfA on July 25th. To avoid prolonged downtime during the upgrade processes, Pui Hin decided to first establish a connection to UHH through a 100 Mbps Ethernet and have the microwave connection tested before the rest of the upgrades. The microwave link tested ok within 30 minutes, but it took most of the day and some tinkering on the cost weighting to get all the MKOCN routers to prefer this path.

    On September 3rd, we upgraded the MKOCN Hilo router to the new 7206VXR-NPE400. As a reminder, this router will be upgraded again as soon as the 7200VXR-GE is available. The number of high bandwidth interfaces we need exceeds the specifications of the NPE400 router. The upgrade was completed within 30 minutes. However, on the same evening we experienced some problems with the microwave OC3 that was unrelated to the router upgrade. Again OSPF failed to chose a correct path due to the reason described above.

    On September 4th, we replaced the 7206 at the summit with the 7206VXR-NPE300 that became available with the Hilo upgrade. The resulting interruption was much longer this time, lasting from 11:00am to almost 2:00pm. This and the upgrade on the previous day allow us to deploy Class-Based Weighted Fair Queueing between the summit and Hilo.

    On September 9th, the Gigabit connection between UHH and the IfA building became operational. It took several hours of troubleshooting before we were able to trace the problems down to some dirty fibers. What confused us was that light was passing through the fibers so the attenuations looked reasonable, and we attributed the CRC errors and packet losses to equipment failure. The UH-ITS fiber OC3 network is currently on hold awaiting replacement of the 6500 switch at West Hawaii.

    Pui Hin next reported on the MKOCN implementation of Class-Based Weighted Fair Queueing. We created a class named H323 to differentiate video conferencing packets from other packets. We identify the packets as H323 if the IP precedence bit is set to a particular value. The H323 class is given a priority of 10 percent of the total bandwidth during congestion.

    Jonathan Chock and Kanoa Willington have assembled an Ultra1 to be used as the secondary DNS server. Pui Hin and Miranda will work on having the DNS server set up.

  5. Layer 3 switching and QoS
  6. Several of the members have experience with Cisco layer 3 switches. Everyone agrees that if QoS is to be deployed, it will be best to use equipment from a single vendor to avoid compatibility issues. In the case of the Polycom performance at Keck, Pui Hin suggested first upgrade the Polycom software to the latest version. If that doesn't solve the problem, then carving out a dedicated T1 for H323 packets from the ATM DS3 might be another option in addition to deploying CBWFQ between the summit and Waimea.

  7. Next Meeting
  8. Thursday, December 12th, 10:00am at Subaru, Hilo

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Last updated December 6, 2002 by Miranda Hawarden-Ogata