The development of telecommunications, Video of Conference non
 becoming overruled matter again with various its constraint. Local Access
 Network (LAN) in the begining didesain for the communications of data. Voice
 and video Communications tried to be developed at data network. Charateristic of
 voice and video communications which must real time and reliable become a
 special question to data network. Do communications voice and video at network
 of LAN still fulfill elegibility of quality able to be accepted?
 This research analyse quality of voice and video at data network by
 observe the distortion of voice and video signal. Delay factor, packet loss, jitter,
 and throughput become analysed parameter. So that elegibility of voice and video
 communications at data network can assess. To test parameters of video and voice
 quality, writer design an data network topology which consist peripheral of Video
 Conference network base on SIP ( Session Initiation Protocol). Writer also design
 some examination scenario to get parameter values.
 From result of analysis and examination say that the quality of video and
 voice at network of LAN still competent and as according to ITU-T standard.
 Quality of which is obtained in applying of Video Conference over network of
 LAN base on SIP is good and good enough. This matter can be seen with value of
 MOS which have been got from some experiment which have been done that is
 gyrating 3.856138 to 3.997465 where the value represent good enough value and
 at scenario 3 in J building, result of attempt show value of MOS 4.007568 which
 included in the good quality.
 Keyword: Video Conference, SIP, LAN