Table of Contents
Introduction
This chapter provides information about videoconferencing, the Cisco IP/VC 3500 product family, the Cisco IP/VC 3530 Video Terminal Adapter (VTA) features, and it provides a physical description of the VTA. The topics are as follows:
H.323 videoconferencing allows users using personal computers, IP telephones, and room-based systems to confer with another or with many other users across the office and around the world over IP networks. It is helping organizations make the transition to an Internet-driven world with instant worldwide connectivity. Spurred by changes in communications technology, low-cost bandwidth, plus continuous improvements in hardware and performance, videoconferencing solutions provide large and small enterprises, government institutions, and educational environments with the tools they need to be more productive, to make decisions faster, to train and educate more effectively, and to save time and avoid the burden of travel.
The Cisco IP/VC 3500 product family is part of the Cisco solution for videoconferencing over IP networks. The family comprises key infrastructure components that provide enterprises and service providers with reliable and easy-to-manage videoconference deployment. The Cisco IP/VC 3500 product family supports H.323 recommendations for videoconferencing on LANs and interoperability with H.320 WAN endpoints. The Cisco IP/VC 3530 VTA allows you to integrate a legacy H.320 room system into the IP network, thus protecting your original videoconferencing investment.
H.323 is the International Telecommunications Union (ITU) standard for real-time audio, data, and video communication over packet-based (IP) networks. It defines the IP-based videoconference components and modes of interaction. H.323 components are as follows:
- The MC is the conference controller. The MC handles negotiation between all terminals to determine common capabilities and controls videoconference resources such as multicasting. The MC does not handle any of the media streams directly.
- The MP handles mixing, switching, and other processing of audio, video, or data bits. The MCU may also rely on the terminals for this processing or it may use MPs in other MCUs.
The Cisco IP/VC 3500 product family consists of the products described in the following sections.
- The IP/VC 3510 MCU is a full service MCU that supports several videoconference call configurations. Configurations the MCU can support include a single three-participant videoconference call using a video bit rates of 1500 kbps, up to 15 simultaneous 128 kbps calls, and up to 24 audio-only calls. The IP/VC 3510 MCU supports ad hoc videoconferences, which means that any user can initiate multimedia (including data), multipoint videoconference calls. The MCU runs unattended and there is no need to schedule videoconferences in advance. Initiators can create a conference ID when creating the call that users dial to join the session. Initiators can also invite additional participants to the videoconference after the call is established.
- The IP/VC 3510 MCU supports cascading and stacking. Cascading is a method for adding videoconference participants by allowing other IP/VC 3510 MCUs to dial in to the videoconference. Stacking is a means of load balancing whereby the MC of an IP/VC 3510 MCU can use the MP services of up to three other IP/VC 3510 MCU to process calls.The IP/VC 3510 MCU also houses an embedded gatekeeper.
- The IP/VC 3510 MCU also houses an embedded gatekeeper.
- IP/VC 3520 gateway translates H.323 and H.320 protocols to allow H.320 WAN terminals to participate in H.323 videoconference calls. This gateway can have up to four BRI interface ports, four V.35 interface ports or a combination of two BRI ports and two V.35 ports. The gateway is equipped with transcoders that provide audio codec transcoding between G.711 and G.728 and between G.723 and G.711to ensure the highest quality audio and video possible.
- Each BRI port supports two B channel, which, when combined, provide a transfer rate of 128 kbps per port. You can configure the IP/VC 3520 Gateway to bond ports for call requiring more bandwidth. You can bond up to three ports for 384 kbps. A unit with four BRI ports can simultaneously support four 128 kbps calls, two 256 kbps calls, or one 384 kbps and one 128 kbps call.
- Each V.35 port supports transfer rates of up to 768 kbps. The V.35 ports also support EIA/TIA-366 signalling which allows the IP/VC 3520 Gateway to set up circuit-switched connections through a DCE device such as an inverse multiplexor (IMUX).
- The IP/VC 3520 Gateway also houses an embedded gatekeeper.
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Note EIA/TIA-232 and EIA/TIA-366 were known as recommended standards RS-232 and RS-366 before their acceptance as standards by the Electronics Industries Association (EIA) and Telecommunications Industry Association (TIA). |
- The IP/VC 3525 gateway translate H.323 and H.320 protocols to allow H.320 WAN terminals to participate in H.323 videoconference calls. This gateway supports the PRI interface. Both T1 and E1 are supported, making this gateway suitable for deployment anywhere in the world. The IP/VC 3525 Gateway supports three calls at 384 kbps, four calls on E1, or up to eight calls at 128 kbps. Audio transcoding is also supported as a standard feature for optimal audio quality.
- The IP/VC 3525 Gateway also houses an embedded gatekeeper.
- The IP/VC 3530 VTA is a self-contained video adapter that allows you to use a legacy H.320 room system or small-group system as an H.323 terminal on the LAN. The IP/VC 3530 VTA provides the room system an IP address and gatekeeper registration. It translates H.320 and H.323 protocol so that videoconference traffic can flow between the room system and other H.323 endpoints on the LAN. These features allow the H.320 room system to initiate and receive videoconference calls through the LAN. Using the IP/VC 3530 VTA allows you to protect your investment in legacy technologies while implementing new IP-based multimedia communications.
The Cisco IP/VC 3530 VTA has the following features:
- H.323 Version 2 support
- 10BASE-T Ethernet connection
- An EIA/TIA-232 modem connection port for remote diagnostics
- Dialing signals (for incoming calls) and address translation
- Session speeds up to 768 kbps
- Dual V.35 DCE interface with EIA/TIA-366
- Far End Camera Control (FECC) support
- Front panel LED display
- Dialing profiles to set bandwidth utilization
- Audio: G.711, G.722 (supports only rates 384/768 kbps), and G.728 (transparent support)
- Video: H.261 CIF and QCIF
- T.120 support
The VTA is built in a low-profile unit designed to comfortably fit in the cabinet of your H.320 videoconferencing system or in a 19-inch rack.
The VTA front panel contains LEDs and a serial port that you can use to configure or monitor the unit via direct connection to a PC serial port or through a modem. Figure 1-1 shows the Cisco IP/VC 3530 VTA front panel.
Figure 1-1: VTA Front Panel
Table 1-1 lists the LEDs that appear on the Cisco IP/VC 3530 VTA and defines the indicator states for each LED.
Table 1-1: Front Panel Activity
| LED
| Color
| Indicates
|
PWR
| Green
| Power is switched on.
|
TEST
| Red
| VTA is powering up or is being configured. This LED turns off after the VTA successfully powers up.
|
WAN
| ---
| ---
|
SESSION (1)
| Green
| Indicates videoconferencing activity.
|
SESSION (2)
| Green
| Indicates videoconferencing activity for two-channel (2B) calls only.
|
LAN
| ---
| ---
|
LINK
| Green
| LAN link is present; port is connected to the network.
|
SESSION
| Green
| Indicates videoconferencing activity on the LAN.
|
For information on using the LEDs for problem solving, see the "LED Indications" section in the "Tips and Troubleshooting" chapter.
The 9-pin EIA/TIA-232 serial port on the front panel allows you to connect the Cisco IP/VC 3530 VTA directly to a PC to use a terminal emulator to assign the VTA an IP address, to run diagnostics, and to monitor VTA status. We recommend that you use the serial connection to assign the unit an IP address before you connect it to the network. Using the serial port to assign the IP address is described in the "Setting the IP Address" section in the "Installing the Hardware" chapter.
The VTA rear panel contains one LAN port, two integrated V.35 interfaces with EIA/TIA-366 switching ports (to connect to the room station); and a power connection.
Figure 1-2: VTA Rear Panel
The VTA has one 10BASE-T port with an RJ-45 socket.
The VTA has two integrated V.35 interfaces with EIA/TIA-366 switching ports. The ports use a 26-pin female connector. VTA units are shipped with a proprietary, split cable with a V.35 Winchester connector and a 15-pin EIA/TIA-366 connector. You must connect both ports for 2B calls.
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Note Connecting the VTA to a room system may require complementary proprietary cables for the room system. |
The VTA power supply automatically adjusts to the supply voltage. The power supply supports 100V to 240V AC at 50/60 Hz.
Posted: Mon Jun 5 13:32:41 PDT 2000
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