This Network Update was distributed via the Exchange Network email alerts list on February 22, 2007.

Weekend Exchange Network Outages Possible

With the growing success of the Exchange Network and U.S. EPA's Central Data Exchange (CDX) has come additional work volume and aging servers. It has now been over seven years since EPA has physically upgraded the majority of the heavily used CDX servers and over three years since EPA performed major upgrades to the operating system. These servers process data coming into EPA and provide core services on the Exchange Network such as authentication and quality assurance services.

To continue high availability and improve services on the Exchange Network, CDX must upgrade aging components and operating systems. EPA will be scheduling outages over the next 4 weekends with several more weekend outages tentatively scheduled in April and May. Exchange Network Partners may experience periods of unavailability during these times. If you intend to conduct data exchanges over the weekends, please consider following up with your exchange partners to confirm
successful transactions during these times.

CDX Normal Production Operational hours are 24 hours a day 7 days a week, which includes a standard system maintenance time window between Friday 6pm - Monday 8am. Realistically it is understood that many Exchange Network partners continue to rely on CDX servers on weekends, so CDX provides system level Systems Administration and Operational support 7 days a week to minimize down-time for CDX as much as possible.

EPA apologizes for these inconveniences and looks forward to the improvements these upgrades will make to the Exchange Network.

More specific information will be provided as soon as it is available. EPA will also be posting notices and updates on CDX at: https://cdx.epa.gov/recent.asp