The connectivity emphasized originally was serial (RS232) and Ethernet. Serial connections through the use of a serial switch (AT&T's ISN) was required by the older time sharing systems. These were suported up to 19.2 Kbps by the ISN.
10 Mbps ethernet quickly became the connectivity technology of choice. TCP/IP was adopted as the principle transport protocol; other transport protocols such as IPX and Appletalk are in use as well. Initially bridges were used in the campus network to manage the rapidly expanding campus network.
In 1990, when a major expansion of workstation computing occurred, an 100 megabits per second DAS FDDI ring was installed as the campus backbone to handle the expanding traffic. Each building was bridged to this backbone with 10 Mbps ethernet.
In 1992, four Cisco AGS+ routers were connected to the FDDI backbone. Each building now had a 10 Mbps connection to a separate port on the router.
In 1995, ISU installed an ATM switch (Cisco Lightstream 100) using OC3 connectivity to further support on-campus traffic.
By 1996, the campus backbone consisted of 12 Cisco routers and a Cisco Lightstream 100 interconnnected by a mix of OC3 ATM, dual-ring FDDI, and a fiber ethernet hub. The routers consisted of: six Cisco 7000, four Cisco AGS+/4, and two Cisco 7513.
In 1998, ISU replaced the Lightstream 100 with a trio of Cisco Lightstream 1010 ATM switches connected by a trio of OC12 links. The resultant campus backbone used Cisco 7500-series routers, Cisco 1010 ATM switches. and Cisco Catalyst 5000 switches. Also indicated on the ISU campus backbone figure are ATM OC3 links to individual buildings that fed Cisco Catalyst 5000 switches which provide 10baseT or 100baseTX connections within those buildings. Some of the routers were connected to both the FDDI backbone and the ATM backbone at OC3 speeds. A few routers were connected only to the FDDI backbone due to the low traffic in those buildings. The Durham Center, which contains most servers for campus distributed computing, contained three FDDI rings interconnected through two routers to the campus FDDI ring and the ATM OC3 switched backbone. Campus was connected to the rest of the world through a DMZ network.
In 2002, ISU replaced the ATM and FDDI backbones with a redundant gigabit ethernet backbone. Most buildings were connected by a single fast ethernet link. The Durham Center was connected to the backbone by redundant gigabit ethernet links. The main campus routers became Cisco 6500 models.
In 2005, the ISU backbone was upgraded to 10 gigabit ethernet.
In 2009, the two main data centers on campus were connected together with a pair of Cisco 6509 routers running as a single logical router, which Cisco calls a VSS system. This allows systems like VMware to migrate applications back and forth between data centers seamlessly.
The Ames Laboratory of the US Department of Energy is located on campus and it has comparable network capacity in its buildings. It is interconnected to the campus network through a firewall network.
Maintained by grpjl@iastate.edu. Last changed 31-Jul-2009.
