IP Videoconferencing

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TheJanet Videoconferencing IP infrastructure complies with the International Telecommunications Union Standardisation Sector (ITU-T) H.323 umbrella of protocols for IP videoconferencing. The service consists of three elements:

  • Multipoint Control Unit (MCU) and IP-ISDN gateway capacity;
  • gatekeepers, that provide call admission control (allowing IP videoconferencing to be managed on user organisation networks) and call routing (allowing users to simply dial other users across the network in a similar way to making phone calls);
  • Global Dialling Scheme (GDS), that works in conjunction with the local, national and international gatekeepers to route calls appropriately.

Security of IP videoconferences can be improved through the use of proxy gatekeepers or H.323 aware firewalls. It should be noted that, as part of the IP videoconferencing service endpoints are automatically dialled from the MCU. An IP dial-in facility is also available to those organisations whose network security may not allow the MCU to dial them.

MCU, gateway, and gatekeeper equipment has been deployed at different co-locations on the JANET(UK) backbone for resilience.