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This chapter provides a general overview of videoconferencing and the Cisco IP/VC 3500 product family. It also describes the physical features and functionality of the Cisco IP/VC 3510 MCU. The topics include:
H.323 videoconferencing is helping organizations make the transition to an Internet-driven world with instant worldwide connectivity. It allows users of personal computers, IP telephones, and room systems to communicate across the office and around the world over IP networks. Spurred by changes in communications technology, low-cost bandwidth, and 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 videoconferencing-over-IP networks solution. The family consists of key infrastructure components that provide enterprises and service providers with reliable and easy-to-manage videoconferencing deployment. The Cisco IP/VC 3500 product family includes the following:
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Note The MCU and gateways have an embedded gatekeeper installed that can be enabled to perform H.323 gatekeeping task. |
H.323 is the International Telecommunication Union (ITU) standard for real-time audio, data, and video communication over packet-based (IP) networks. The standard defines the IP-based videoconference components and modes of interaction. H.323 components are as follows:
The following sections provide brief descriptions of each of the Cisco IP/VC 3500 family products.
The Cisco IP/VC 3510 MCU allows multiparty, multimedia videoconference calls over IP networks. LAN users with H.323-compatible terminals and WAN users accessing the LAN through a H.323 gateway can use the MCU to initiate videoconference calls. Calls are initiated in an ad hoc manner.
The MCU supports the following:
Continuous presence is a process whereby multiple conference participants are displayed on each participating terminal simultaneously. The MCU displays up to four participants. The call initiator and the first two participants to be invited to the videoconference or to join it are displayed for the duration of the call (or until they are dropped). The fourth participant to display is the latest of the remaining participants to be given the floor (voice-activated).
Cascading is a method of allowing the number of participants to expand beyond what a single MCU can support. Cascading allows one Cisco IP/VC 3510 MCU videoconference to join or be invited into another Cisco IP/VC 3510 MCU videoconference. The joining MCU videoconference becomes a participant of the videoconference it joins and is treated like the other participants. The host MCU sends the joining MCU the processed data streams, which the latter distributes to its videoconference participants. In this way, all of the participants in the expanded videoconference receive the same information.
The Cisco IP/VC 3510 MCU supports a videoconference-call Web page that can be accessed through a Web browser for each active videoconference. The Web page lists information about the terminals participating in the conference and allows the Web browser user to perform functions such as invite participants to the conference, lock the camera on a particular participant, disconnect participants, and enable data sharing for participants.
Cisco IP/VC 3510 MCUs can be stacked to provide load balancing. The MCU contains both MC and MP modules. Stacking allows the MCU administrator to configure the modules separately and to link up to four MPs to one MC. Stacking can reduce the number of MCU services the environment needs to provide while increasing the processing capacity of the composite MCU.
The Cisco IP/VC 3510 MCU also has an embedded gatekeeper.
The Cisco IP/VC 3520 Gateway translates H.323 and H.320 protocols to allow H.320 WAN terminals to participate in H.323 videoconference calls. The gateway can provide the following:
Each BRI interface port supports two B channels. The ports can be bonded to provide a composite transfer rate of 128 kbps. You can configure the Cisco IP/VC 3520 Gateway to bond up to three ports for calls that require transfer rates of up to
384 kbps. A unit with four BRI interface 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 signaling, which allows the Cisco IP/VC 3520 Gateway to setup circuit-switched connections through a DCE device such as an inverse multiplexer (IMUX).
The Cisco IP/VC 3520 Gateway also houses an embedded gatekeeper.
The Cisco IP/VC 3525 Gateway translates 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 Cisco IP/VC 3525 Gateway doses the following:
The Cisco IP/VC 3525 Gateway also houses an embedded gatekeeper.
The Cisco 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 Cisco IP/VC 3530 VTA does the following:
These features allow the H.320 room system to initiate and receive videoconference calls through the LAN. Using the Cisco IP/VC 3530 VTA, you can protect your investment in legacy technologies while implementing new IP-based multimedia communications.
The MCU includes the following features:
This section describes the front and rear panels of the Cisco IP/VC 3510 MCU.
The Cisco IP/VC 3510 MCU contains LEDs and a serial port. The serial port can be used to configure and monitor the MCU through direct connection to a PC serial port or through a modem. Figure 1-1 shows the Cisco IP/VC 3510 MCU front panel.
The LEDs that appear on the MCU front panel are as follows:
| Status of LED | CPU Load Range |
|---|---|
Not illuminated | Load in range 0-3% |
One flashed LED | Load in range 3-20% |
One illuminated LED | Load in range 20-40% |
Two illuminated LEDs | Load in range 40-60% |
Three illuminated LEDs | Load in range 60-80% |
Four illuminated LEDs | Load in range 80-100% |
The 9-pin EIA/TIA232 serial port on the front panel allows you to connect the MCU directly to a PC serial port. Using a terminal emulator you can use the serial port to configure the MCU IP address requirements, run the diagnostic utility, and monitor the MCU status. Use the serial connection to assign the unit an IP address before you connect the unit to the network. Assigning the IP address is described in the "Setting the IP Address" section in "Installing the Hardware."
The MCU rear panel (see Figure 1-2) provides LAN and power connection ports.
The MCU has one 10/100BASE-T port with an RJ-45 socket. The port supports 10 Mbps and 100 Mbps transfer rates and operates at half-duplex only. You must use Category 5 network cable for 100 Mbps capability.
The gateway power supply automatically adjusts to the supply voltage. The power supply supports 100V to 240V AC at 50/60 Hz.
Posted: Wed Sep 20 09:09:02 PDT 2000
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