The following information is included to alert you about safety recommendations and best practices to be followed when working with this equipment.

Always follow ESD-prevention procedures when removing and replacing components. These procedures include:

• Ensure that the chassis is electrically connected to earth ground.

• Wear an ESD-preventive wrist strap, ensuring that it makes good skin contact.

• Connect a clip to the ESD-strap connection jack (to the left of the power switch on the rear of the chassis) or to an unpainted chassis frame surface.

Caution

For safety, periodically check the resistance value of the antistatic strap, which should be between 1 МΩ and 10 МΩ.

The installation location (room, closet, or cabinet) for Cisco VG310 and Cisco VG320 should always be well ventilated and provide adequate air circulation to ensure proper cooling. The room temperature should be between 32 °F and 104 °F (0 °C to 40 °C).

Note	The Cisco VG310 and Cisco VG320 analog voice gateway chassis is designed for back-to-front airflow.

Allow space at the rear of the chassis for cable connections. Also consider the need to access the chassis for future upgrades, maintenance, and troubleshooting.

Use the following information to plan your equipment-rack configuration:

• Allow clearance around the rack for maintenance.

• Enclosed racks must have adequate ventilation. Ensure that the rack is not congested, because each voice gateway generates heat. An enclosed rack should have louvered sides and a fan to provide cooling air. Heat generated by equipment near the bottom of the rack can be drawn upward into the intake ports of the equipment above it.

• When mounting a chassis in an open rack, ensure that the rack frame does not block the ports. If the chassis is installed on slides, check the position of the chassis when it is seated in the rack.

Chassis grounding is provided through the power cable, which uses a standard grounding plug. However, the chassis also requires a reliable earth ground using the earth ground lug and hardware provided. For more information, see Installing the Ground Connection.

You can connect Cisco VG310 or Cisco VG320 to either an AC power source or a +12V DC power supply.

Caution

The chassis provides inputs for both AC and DC power. Design your installation to use only one type of power. Do not use AC and DC power at the same time. If you do, the unit stops operating, and you must reboot it with only a single power source.

For more information, see Connecting Power.

The cable types are dependent on the Cisco VG310 or Cisco VG320 analog voice gateway that you are using. For more information, see Interfaces and Service Capabilities of Cisco VG310 and Cisco VG320 and Cable Specifications and Information.

When planning your installation, consider distance limitations and potential electromagnetic interference (EMI) as defined by the Electronic Industries Association (EIA). Distance-limitation information is included for the following Voice Gateway ports:

• Gigabit Ethernet ports—The maximum segment distance for Gigabit Ethernet is 330 feet (100 meters) (specified in IEEE 802.3).

• FXS analog voice ports—The maximum distance is established by a total allowable loop resistance, including the phone or terminal equipment, of 600 Ohms.

Cisco VG310 and Cisco VG320 include an asynchronous serial console port and an auxiliary port. The console and auxiliary ports provide access to the unit either locally using a console terminal connected to the console port, or remotely, using a modem connected to the auxiliary port. This section discusses important cabling information to consider before connecting the unit to a console terminal or modem.

The main difference between the console and auxiliary ports is that the auxiliary port supports hardware flow control and the console port does not. Flow control paces the transmission of data between a sending device and a receiving device. Flow control ensures that the receiving device can absorb the data sent to it before the sending device sends more. When the buffers on the receiving device are full, a message is sent to the sending device to suspend transmission until the data in the buffers has been processed. Because the auxiliary port supports flow control, it is ideally suited for use with the high-speed transmissions of a modem. Console terminals send data at speeds slower than modems do; therefore, the console port is ideally suited for use with console terminals.

When you run cables for any significant distance in an electromagnetic field, interference can occur between the electromagnetic field and the signals on the cables. This has the following implications on the installation of terminal plant cabling:

• Unshielded plant cabling can emit radio interference.

• Strong electromagnetic interference (EMI), especially as caused by lightning or radio transmitters, can destroy the EIA/TIA-232 drivers and receivers in Cisco VG310 or Cisco VG320.

Consider the following guidelines:

• To prevent emitted radio interference, use twisted-pair cables with a good distribution of grounding conductors in your plant cabling.

• If you have cables exceeding recommended distances, or if you have cables that pass between buildings, give special consideration to the effect of lightning strikes or ground loops. If your site has these characteristics, consult experts in lightning suppression and shielding. The electromagnetic pulse caused by lightning or other high-energy phenomena can easily couple enough energy into unshielded conductors to destroy electronic devices. Take precautions to avoid these problems by providing a properly grounded and shielded environment and by installing electrical surge suppression.

• All module openings must be either occupied or covered to prevent electromagnetic interference—you must either install a module in its vacant slot or install a cover plate over the opening.

• Consult experts in radio-frequency interference (RFI) for advice on the prevention of electromagnetic interference.

The following are the tools and parts required to install the voice gateway:

• ESD-preventive cord and wrist strap.

• Standard flat-blade screwdrivers-small (3/16-in. [4 mm to 5 mm]) and medium (1/4-in. [6 mm to 7 mm]):

  • To attach brackets to a rack or wall.

  • To install or remove modules.

  • To remove the cover if you are upgrading memory or other components.

• Phillips screwdriver for attaching brackets to the chassis.

• Mounting brackets and screws for 24-inch rack, if required:

  • Four Telco machine screws for installing the chassis in a rack (use the screw size required by the rack).

• Screws and anchors for wall-mounting, if required:

  • Eight wood screws or other fasteners for installing the chassis on a wall. An additional starter screw can be used to facilitate wall-mounting.

• Wire crimper.

• Wire for connecting the chassis to an earth ground:

  • AWG 14 (2 mm²) or larger wire for NEC-compliant chassis grounding.

  • AWG 18 (1 mm²) or larger wire for EN or IEC 60950-compliant chassis grounding.

  • For NEC-compliant grounding, an appropriate user-supplied ring terminal, with an inner diameter of 1/4 in. (5 mm to 7 mm).

In addition, depending on the type of modules you plan to use, you may need the following external equipment:

• Console terminal or personal computer with terminal emulation software.

• Cables for connecting to the WAN and LAN ports (dependent on configuration).

• PC-running terminal-emulation software for administrative access.

• Modem for remote access.

• Analog voice RJ-21 cable.

• Ethernet switch.

• Modem for remote configuration.

We recommend that you use an installation checklist and maintain a Site Log.