2002 - cesnet

more, there are several versions of numbering plans which can significantlyfacilitate the access to H.323 infrastructure within the Internet2 project (ViDeinitiative).Pursuant to information search and testing carried out during the previousperiod, we purchased several stationary videoconference sets for H.323 thisyear (Polycom ViewStation, FX, SP128 and ViaVideo). These sets are designedfor standard videoconferences with an international community of researchers(SURFnet, Megaconference IV, TERENA, Dante, etc.) and for the provisionof support to notable events supported by the CESNET association (ISIR).Selected sets serve researchers in the H.323 team for the verification of testedmechanisms in the H.323 infrastructure.The multipoint H.323 videoconferences have so far been solved in the form ofa compromise. Videoconferences with four linked IP clients are solved directlyby one of the videoconference sets (Polycom ViewStation FX) and – pursuant toan agreement with the supplier of these stations – there is also MCU’s availablewith the possibility of twelve connected IP clients. The portfolio of these servicesmay be further extended by MCU in the Internet2 and some other foreignpartners.6.3.3 Tools for Shared Collaborative EnvironmentConcerning the character of business meetings and conferences, it is obviousthat good quality of sound is very important. The human ear is so sensitive thateven some minor dropouts and low quality of sound recording will make theuse of the system rather complicated. The research group decided not to developtheir own tools for sound handling but tested various versions of the ratprogram and various types of microphones. During the year, the team managedto get hold of an instrument for echo cancellation, test it in combination withomni-directional microphones and introduce it in routine operation.Other important information shared during a business meeting is the image ofindividual participants. Even though this information source is demanding interms of amount of transmitted data, it proved to be quite robust with respect tothe quality of transmission and the signal, as this information is not so substantialfor a virtual business meeting.Shared workspace is a tool for which users express various requirements – fromsharing static images with a large number of details, to sharing animations andmoving images, MS PowerPoint presentations and T E X. Modifications of theshared whiteboard tool, wbd, described in last year’s report were implementedin the new version, i.e., wbd dynamically links functions for imaging, rotationand size changes from the Imlib2 library, depending on the format of the loaded84 High-speed National Research Network and its New Applications 2002