The ICT Directorate allows users of the telephone network, regardless of call block, to communicate via telephone free of charge with users from 19 academic institutions. The communication is feasible with voice transmission via the Academic Network (GUNET). The required voice technology is Voice over IP (VoIP).

The 20 academic institutions involved so far in the GUNET’s VoIP service and the numbers appear in the table below.



Calling Numbers

Aristotle University of Thessalonica


Democritus University of Thrace

2541079xxx, 2531039xxx, 2551030xxx, 2552041xxx


210747424x, 210747425x, 210747426x, 210747427x, 210747568x

National and Kapodistrian University of Athens

2107274xxx, 2107275xxx, 2107276xxx, 2107277xxx, 2107461xxx, 2107462xxx, 2103688xxx, 2103689xxx

National Technical University of Athens

2107721xxx, 2107722xxx, 2107723xxx, 2107724xxx

Research Academic Computer Technology Institute

26109602xx, 26109603xx, 26109604xx, 210693060x, 210693070x, 210693071x, 210693072x, 210693073x, 210693074x, 210693075x

Foundation for Research and Technology


Athens University of Economics and Business


Aegean University

2241099[0-4]xx Ρόδος, 2251036xxx Λέσβος, 2271035xxx Χίος, 2273082xxx Σάμος, 2281097xxx Σύρος, 2106492[0-4]xx Αθήνα

University of Western Macedonia

2461056[2-7]xx Κοζάνη, 2385055[0-2]xx Φλώρινα

University of Thessaly

2421074xxx, 2421093[0-2]xx, 2421006[3-5]xx, 2410565xxx, 2431047[0-2]xx, 2441066[0-2]xx

University of Ioannina

2651095xxx, 26510964xx, 26510965xx, 26510966xx, 26510967xx, 26510968xx, 26510969xx, 2651097xxx, 2651098xxx

University of Crete

2810393xxx, 2810394xxx, 2810545xxx, 2831077xxx, 2103702040

University of Patras


University of Pireaus


University of Peloponnese

274107498x , 274107499x , 274107435x Κόρινθος
273108965x , 273108966x , 273108967x , 273108968x , 273108971x, 273108972x Σπάρτη
275209610x , 275209611x , 275209612x , 275209613x Ναύπλιο
272106510x , 272106511x , 272106512x , 272106513x Καλαμάτα
27103721xx , 27103722xx , 271023012x , 271023013x Τρίπολη
210747540x , 210747541x Αθήνα

Technical University of Crete


TEI of Athens


TEI of Crete


TEI of Messolonghi

26310582xx, 26310583xx, 26310584xx

Harokopion University

21095491xx, 21095492xx, 21095493xx



Users of the telephone network may establish calls with the institutions above, whether or not they can make long distance calls, free of charge.
The method you should follow is:

  1. To access the service, type the prefix “89” instead of the prefix “0” you normally type to connect to the public telephone network of OTE.
  2. Afterwards you type the ten-digit number of the institution. After a short interval the call is established. Optionally you may avoid waiting, typing “#” directly after the number.


  1. Calling a user from University of Athens, you type 892107274000 or alternatively 892107274000#.
  2. Calling a user from University of Thessaloniki, you type 892310996000 or alternatively 892310996000#.
© Technical University of Crete 2012