CFHT Information Bulletin Number 37, Semester 97II

Upgrade to CFHT Headquarters-Summit Data Communications

Bob Link, CFHT (

Currently, data communications between the CFHT headquarters in Waimea and the CFHT dome on Mauna Kea are via a T1 line which is rated at about 1.5 mps. This leased line is strictly for the use of CFHT. However, the line is usually very busy as it is used for several important functions. It allows CFHT personnel to perform tasks on summit machines and instruments remotely, it allows disks to be shared anywhere at CFHT, and acquired data at the summit is copied down to Waimea for archiving via this T1 line. The line also provides access to the Internet for such activities as email exchange, and web access. At the summit, CFHT is part of a fiber network shared by all of the observatories. This shared summit network travels down to Halepohaku at the 9,000 ft. level. From Halepohaku, all the observatories share a T1 line connected to UH-Manoa in Honolulu. CFHT then shares a T2 line to the U.S. mainland via Sprint.

Our Headquarters-summit communications capability is just barely adequate at this time. With the advent of the UH8k instrument and the future CFH12k and Megacam projects the T1 line will not be able to handle the load produced by the gigabytes of files being created, reduced, and transported every night. Serendipitously, GTE Hawaiian Telephone company is about to complete a major communications infrastructure upgrade project which will bring fiber to Wamea and Hilo for use by observatories. This upgrade will allow CFHT to lease a DS3 (45 mbps) line which is almost 30 times faster than the T1 line currently in use. While the cost of leasing the DS3 line is quite reasonable compared to the T1 line, CFHT must also replace the communications equipment which connects the DS3 line to the CFHT LANs in Waimea and the summit. After an exhaustive search Cisco routers with ATM and Fast Ethernet modules as the interface equipment to the DS3 line and CFHT LANS were chosen. This equipment offers high performance and expandability. The DS3 line should be in operation before the end of the year.

CFHT Information Bulletin Number 37, Semester 97II
Copyright © 1997, Canada-France-Hawaii Telescope