-----Original Message----- From: BrownLJ@stentor.ca [mailto:BrownLJ@stentor.ca] Sent: Tuesday, January 26, 1999 1:36 PM To: Regan, Sharon Cc: GreenKB@stentor.ca; GodardD@stentor.ca; WongR@stentor.ca; SavardCR@stentor.ca; MenardPA@stentor.ca; McfetridgeM@stentor.ca; FournierLC@stentor.ca; SchroederJP@stentor.ca; ShurtliffMJ@stentor.ca; LockeMW@stentor.ca; WarrenGA@stentor.ca; PackmanJ@stentor.ca; ReilleyJA@stentor.ca; RochfordM@stentor.ca; GirardLP@stentor.ca; BirdBR@stentor.ca; WarrenL@stentor.ca Subject: Concert Network Maintance - 8.5 Upgrade Domain 4 (UK) Ms. Regan; On February 12th, 1999, Concert will be upgrading Subnet 4 (UK) to System Software 8.5. This upgrade is to begin at 23:00 GMT (18:00 Eastern) with a maintenance window duration of 10 hours. The initial impact to the Frame Relay network will be minimal; the expected downtime will be less than 45 seconds for most nodes and up to 2 minutes of data interruption for some. There is also a possibility of reroutes, although the chance is small and would be like any other reroute that would occur upon a trunk failure. There is an expectation that approximately 10% of the PVC's will experience failures for which a script will be executed, on each node, to correct the problem. All issues that have been observed with the Subnet 5 (Germany) upgrade have been addressed in this script and it is expected to take approximately 2 hours to complete. The lower the number of PVC's on a node, the quicker the reroute time. The reroutes will be noticeably faster as System Software 8.5 supports trunk based loading. Please note however, by resetting connections throughout the Subnet, each PVC will be impacted twice. This is unfortunate but unavoidable in order to accomplish the upgrade. Regards, Linda J. Brown CCSC - Concert Canada Service Center Concert Change Management 613-781-9382