Table of Contents
Introduction
This chapters provides a information about videoconferencing, Cisco IP/VC 3500 Series products, Cisco IP/VC 3525 Video Gateway features, and a physical description of the Cisco IP/VC 3525 Video Gateway. The topics are as follows:
- Videoconferencing Overview
- Cisco IP/VC 3500 Series Product Family
- About the Cisco IP/VC 3525 Video Gateway
- Cisco IP/VC 3525 Video Gateway Features
- Cisco IP/VC 3525 Video Gateway Physical Description
Videoconferencing 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 Series product family is Cisco's videoconferencing solution. It is comprises several products that are developed for enterprises and service providers who want a reliable and easy to manage network infrastructure for videoconferencing applications deployment. Cisco videoconferencing products enable video applications over IP networks, and integrate legacy H.320 system, thus protecting enterprises' original investment in videoconferencing.
H.323 is the International Telecommunications Union (ITU) standard for real-time multimedia communications and conferencing over packet-based (IP) networks. Sending videoconferences over standard ISDN lines is expensive and prone to connectivity problems. Because of specialized, dedicated equipment needs, ISDN-based videoconferencing is often restricted to special sites and rooms. Network-based H.323 videoconferencing is the next-generation standard. H.323 is more cost-effective, offering greater flexibility and scalability: wherever there is a LAN connection, H.323 videoconferencing equipment will operate.
The H.323 specification defines a number of new network components that interoperate with other standards-compliant endpoints and networks by virtue of an H.323/H.32X gateway.
Following are the network components defined by the H.323 standard:
- Terminals are the endpoints on the LAN which provide for real-time, two-way communications. Most H.323 terminals are desktop computers running H.323 compliant software. All terminals must support voice communications while video and data are optional. However, if these other media are supported, H.323 specifies what modes of operation are required so that all terminals supporting video and/or data can work seamlessly together.
- Multipoint Controller Units consist of a required multipoint controller (MC) and an optional multipoint processor (MP) or processors. The MC is the conference controller. The MC handles negotiation between all terminals to determine common capabilities and controls conference resources such as multicasting. The MC does not deal directly with any of the media streams. This is left to the MP, which does the mixing, switching, and other processing of audio, video, and/or data bits.
- Gatekeepers perform crucial control and administration tasks for H.323 entities while providing network administrators the ability to incorporate management and security policies into the network. Although the H.323 recommendation describes the gatekeeper as an optional component of a functional H.323 system in practice the gatekeeper is essential. The H.323 gatekeeper is responsible for providing address translation between LAN aliases and IP addresses, call control and routing, basic telephony services such as directory services and PBX functions, H.323 traffic bandwidth usage control and total network usage control and the implementation of overall system management and security policies.
- Gateways are devices that provide the translation services between H.323 conferencing endpoints on the IP network and other ITU-compliant terminals (for example, H.320 room systems) on other circuit switched networks.
- Terminals, gateways and multipoint controller units are also known as H.323 endpoints. The collection of all terminals, gateways, and MCUs managed by a single gatekeeper comprise an H.323 Zone.
The Cisco IP/V 3500 Series consists of the following products:
- IP/VC 3510 Multipoint Control Unit (MCU)
- The MCU enables conferences between three or more endpoints. Multiple participants in multiple locations can attend the same meeting with full real-time interactivity. The MCU is designed to allow users to spontaneously initiate full multimedia, multipoint conferences, including data conferencing. It runs unattended and there is no need to schedule conferences in advance. With the MCU, a user simply dials the conference number and the MCU automatically sets up the session. Others wanting to join dial that same number and are immediately connected to the conference. Alternatively, the person initiating the conference can add users to the conference.
- Each MCU can support up to 15 simultaneous users. Its compact design also provides a way to cascade multiple MCUs together to support larger conferences. For small videoconferencing networks, the MCU features built-in gatekeeper functions. It is based upon a highly reliable RISC architecture and is simple to install.
- The IP/VC 3520 and the IP/VC 3525 Gateways are self-contained systems that translate between H.323 and H.320 protocols, and convert multimedia information from circuit switch (ISDN) to H.323 IP packets. They let you connect your legacy ISDN-based H.320 systems to IP-based H.323 videoconference endpoints.
- The IP/VC 3520 Gateway offers two or four BRI or V.35 WAN ports or a combination of both BRI and V.35 ports. It supports up to four calls at 128 kbps (BRI interfaces) or 384 kbps (V.35 interfaces). All ports include audio transcoders for optimal video/audio quality and bandwidth utilization. The BRI ports come standard with echo cancellation. The V.35 ports support EIA/TIA-366 signaling for call setup.
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 offers a single PRI interface to the ISDN network. It supports T1 and E1 connections, making it 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.
- Like the IP/VC 3510 MCU, the IP/VC Gateways offer built-in gatekeeper functions for small videoconferencing networks, a compact design and reliable RISC architecture.
- The IP/VC 3530 Video Terminal Adapter (VTA) is a self-contained video interface that connects one H.320 system to an IP network. It allows companies to protect their investment in legacy technologies while implementing new IP-based multimedia communications. The IP/VC 3530 VTA connects an H.320 room-based system or small-group system to a LAN. It offers two V.35 WAN interfaces, EIA/TIA-366 signaling, a low-profile compact design, and RISC architecture to ensure reliability and easy installation.
The Cisco IP/VC 3525 Video Gateway is a network hardware solution that allows audio, video and data conferencing to occur between H.323-compliant LAN endpoints and H.320-compliant terminals. The Cisco IP/VC 3525 Video Gateway translates H.323 and H.320 protocols so that LAN users can communicate with ISDN and PSTN users.
The Cisco IP/VC 3525 Video Gateway is also referred to throughout this document as the Video Gateway.
The Cisco IP/VC 3525 Video Gateway has the following features:
This section describes the front and rear panels of the Cisco IP/VC 3525 Video Gateway.
The Cisco IP/VC 3525 Video Gateway contains LEDs and a serial port that can be used for configuration and monitoring the unit. Figure 1-1shows the Cisco IP/VC 3525 Video Gateway front panel.
Figure 1-1: Cisco IP/VC 3525 Video Gateway Front Panel
Table 1-1 list the LEDs that appear on the Cisco IP/VC 3525 Video Gateway and defines the indicator states for each LED.
Table 1-1: Cisco IP/VC 3525 Video Gateway LED Indicator Definitions
| LED
| Color
| Indicates
|
LAN
| Green
Off
| LAN link is present; port is connected to the network
Link not present.
|
WAN
| Green
| Selected port is in use
|
Power
| Green
| Power is switched on
|
Self Test
| Orange
| Gateway is in Power On Self Test, or is in reset during configuration.
|
CD (Carrier Detect)
| Green
Off
| Carrier received on line
Faulty connection.
|
ACT (Active Session)
| Green
Off
| Call using this port
No session.
|
LBPK
| ---
| ---
|
ALRM
| Green
Off
| Remote source indicates an error or the receiving port detects loss of signal, loss of frame, or excessive errors.
Error-free connection with no alarm signals.
|
For information on using the LEDs for problem solving, see "LED Indications" in the "Troubleshooting Tips" chapter.
The 9-pin RS-232 serial port on the front panel allows you to connect the Cisco IP/VC 3525 Video Gateway directly to a PC serial port. Using a terminal emulator you can configure the Video Gateway's IP address, run the Video Gateway diagnostics, and monitor the Video Gateway status. Cisco Systems recommends that you use the serial connection to assign the unit an IP address before you connect the unit to the network. Using the serial port to assign the IP address is described in "Setting the IP Address" in the "Installing the Hardware and Configuration Software" chapter.
The Cisco IP/VC 3525 Video Gateway rear panel (see Figure 1-2) provides the LAN, WAN, and power connections.
Figure 1-2: Cisco IP/VC 3525 Video Gateway Rear Panel
The Cisco IP/VC 3525 Video Gateway has one 10/100BaseT port with an RJ-45 sockets. The port allows for 10 Mbps or 100 Mbps bandwidths. You must use category 5 network cable for 100 Mbps capability.
The Cisco IP/VC 3525 Video Gateway has 1 PRI module with a RJ-45 socket for direct telephone connection. Two alarm LEDs are associated with the PRI port. Table 1-2 defines the LED alarm indicator states.
Table 1-2: PRI WAN Port Alarm
| LED
| Color
| Indicates
|
|---|
Red Alarm
| Orange
Off
| Gateway has lost frame alignment on the PRI line.
Error-free connection
|
Yellow Alarm
| Green
Off
| Loss of frame alignment at the remote unit.
Error-free connection
|
Posted: Fri Nov 12 08:12:17 PST 1999
Copyright 1989-1999©Cisco Systems Inc.
