IP telephony

The service supports interconnections of IP telephony networks of institutions within the CESNET e-infrastructure in the Czech Republic and abroad and enables calls between exchanges and IP telephony networks (including audio and video conference service) free of charge.

The service is based on signaling protocols SIP and H.323. Routing is performed at central elements with high call capacity. Most institutions access the service using own voice gateway (in majority Cisco) connected through ISDN PRI (E1) interface to the classic phone exchange of the institution. These gateways are connected to interconnecting elements of the e-infrastructure. Another option for the institutions with own IP phone network is to agree upon the interface (interconnection points, protocols, contacts etc.).

The requirement is a quality network connection (ideally low latency and jitter and minimal packet loss) with capacity of 80 kbps per one call (for G.711, G.722 codecs), use of pre-defined interface, and maintaining contact and technical information up-to-date. The collaboration with technical contacts during solving problems related to the user equipment is a must (access to gateways).

Key benefits

  • Connecting IP telephony users networks without transit fees.

Target audience

The service is available to individuals/teams from the entities connected to the CESNET e-infrastructure.


The service is available free of any additional charge to the entities connected to the CESNET e-infrastructure.


The interested entity should send a request to the User care department. The following is the commissioning of the service in cooperation with the CESNET worker. The setup time varies according to the difficulty of the configuration and the course of the tests.

Related services

Last change: 22.5.2017