3Com S330 manual Point-to-Point Video Conferencing

238APPENDIX B: PATHBUILDER S330/S310 MODULE AND APPLICATION OVERVIEW

Figure 177 depicts the effects of structured versus unstructured service on the DS1 framing.

Figure 177 Structured Versus Unstructured Effects on Transit DS1

PathBuilder S330/S310 Interface
DS1
	AAL 1	DS0	DS0	DS0	DS0	A&B
ESF
FDL			DS1 Structured N x 64 Kbps

Bit

Bucket

PathBuilder S330/S310 Interface

DS1

ESF

FDL

DS1 = 1,544 Mbps

DS0 = 64 KbpsDTE

Timing

DS - Digital Signal

ESF - Extended Superframe

AAL 1 DS1

DS1 Unstructured

Video Conferencing The serial port of the PathBuilder S330/S310 CBR module has two types of interface: V.35 for video data and RS-366 for video dial. These interfaces are broken out from a 50-pin connector on the S330/S310 via a Y cable.

The V.35/RS-366 serial CBR connector is ideal for directly connecting to H.320 video codec devices such as PictureTel, Vtel, and CLI. These device applications are used for group-room conferencing applications and distance learning, typically over an ISDN dial network. The PathBuilder S330/S310 platforms simulate a dial ISDN network over an ATM network, allowing you to integrate voice, video, and data on a single ATM network.

The RS-366-based video dial feature allows a dial-based video session using the ATM circuit emulation provided by the PathBuilder S330/S310 platforms. The PathBuilder S330/S310 supports two modes of video conferencing: point-to-point and multi-point.

Point-to-Point Video Conferencing

In point-to-point video conferencing two or more PathBuilder S330/S310 CBR modules are connected via their serial (V.35/RS-366) ports. To set up point-to-point conferencing, you build virtual circuits (defined by transmit and receive vpi/vci combinations) to connect the remote units. To activate a point-to-point conference, both ends must dial their respective destination phone numbers over the RS-366 interface. Video data is then transmitted and received over the V.35 interface. No bandwidth is allocated until the connection is made.