Technical Information About UNTVN

The University of North Texas Videoconferencing Network (UNTVN) is a compressed video network connecting several videoconferencing classrooms in the Dallas/Fort Worth Metroplex.  All of the sites within UNTVN use Tandberg codecs.  The system also uses an Accord MGC-100 Multipoint Control Unit (MCU) that provides for multipoint conferences.  All of the systems support H.320 standard algorithms. Some of our Tandberg systems and the Accord MCU will also support H.323 standard algorithms. The Accord MCU also functions as a Gateway between H.320 and H.323. All imuxes are set to Bonding Mode 1 to allow for off network connections to other imuxes that also support Bonding Mode 1.

UNTVN is inter-connected by high-capacity phone lines known as T1 lines.  These phone lines, in conjunction with the imuxes, allow all of the sites within UNTVN to connect with each other at line rates of Nx56 or Nx64 Kbps where N = 1 to 23, 112Kbps - 1.472Mbps. Videoconferences are typically connected at rates of either 384K (6 Channels) or 768K (12 Channels), though 128K (2 channels) or 512K (8 Channels) can be accommodated.

UNTVN has 7 BRI's that can connect any of our sites to any other site around the world that is connected to the publicly switched network. These BRI's are configured for outgoing calls only and will incur long distance charges. Contact UNTVN Scheduling (untvn-scheduling@cc.admin.unt.edu) for the current charge rate.

Further, UNTVN is connected to Internet2 to conduct videoconferences using the H.323 standard. Successful videoconferences have been held using commodity internet, though extensive testing is required and results cannot be guaranteed. 

 

Connecting to UNTVN

Any site that is not solely on a long distance carrier's private network can dial to any UNTVN site or MCU port directly.  Additionally, UNTVN has access to the following networks:  VIDNET, TTVN, EdNet10, RETN and the publicly switched network. 

Various codec and imux parameters must also be configured correctly before a connection to a UNTVN site is attempted.  Currently, UNTVN Tandberg codecs are set for "automatic configuration."  This setting will allow them to receive a call with parameters as described in the table below.

Note: Tandberg codecs can only support standards based calls.

 

Codec and Imux Parameter Settings

	Imux Calls	Dual Calls
Parameter	Standards	Standards
Imux Protocol	Bonding Mode 1	None
Communication Protocol	H.221	H.221
Video Algorithm	H.261	H.261
Audio Algorithm	64K G.711u	16K G.728
Video Format	FCIF	FCIF

 

Site Certification

The entire site certification process can generally be completed within 5 business days.  After receiving the appropriate technical information, the technical support staff at UNTVN, can usually schedule a systems test within 2-5 days. After a successful test, classes or other activities requested to be scheduled with UNTVN Scheduling can be confirmed. All sites in a scheduled class/activity will connect 30 minutes prior to the start of the videoconference.