Structure of the network


The network has been implemented with ethernet technology using a tree like structure. The desktops are connected to the edge switches using unshielded cat 6 cabling. Single or multimode fiber has been used for connections between switches and for long reach connections.

The network is fully switched and it has been implemented using stackable layer 2 edge switches and a modular layer 3 main switch.

The edge switches have been connected using  two  1Gbit/s connections for speed and reliability reasons. All desktops have been connected with a 1Gbit/s link. The compute servers have been connected with  10Gbit/s links to  aggregate switches, which are connected with two 10 Gbit/s  to the main switch because of  speed and reliability reasons.

Backend servers (ees2-ees10) have been connected directly to the main switch. This helps to narrow down the impact area in case of network problems.

Compute clusters have been built in their own racks with their own top of the rack or in blade enclosure switches. This helps to keep the cabling simple and keeps the traffic between the compute nodes as local as possible.

The picture above gives a simplified description of the connections. The picture includes only the ITEENET (previously EENET) part of the network. In additions of that part the network includes separate firewalled networks for e.g.

  • system maintenance (ADMNET)
  • printers (PRINTNET)
  • student labs (STNET)
  • wireless network (PANOULU)
  • measurement and control instruments (MEASNET)
  • CWC research group  (CWCNET)
  • etc.



A full backup from data on the server disks will be stored on tapes every 2 months. Daily changes will be stored every night.

The daily backup starts at 02:33 and takes a few hours. Full backup takes over 2 days. Daily backups and their indexes will be kept for 6 months.  Samples of full backups will be kept several years.

The backup robot (Dell PowerVault ML6020) has 133 tape slots of which 114 are for data and 18 are I/O slots. Currently 2 LTO6 tape units are used with uncompressed capacity of 2.5 terabytes.  The total  uncompressed capacity of the backup system is 285 terabytes. Both the control of the robot and tape units are directly connected to the backup server  ees6 using SAS bus.

Last updated: 24.9.2015