TANDBERG Gatekeeper User manual

TANDBERG Gatekeeper
User Manual
Software version N5.0
D13381.05
This document is not to be reproduced in whole or in part without permission in writing from:

TANDBERG Gatekeeper User Manual
Trademarks and copyright
Copyright 1993-2006 TANDBERG ASA. All rights reserved.
This document contains information that is proprietary to TANDBERG ASA. No part of this
publication may be reproduced, stored in a retrieval system, or transmitted, in any form, or
by any means, electronically, mechanically, by photocopying, or otherwise, without the prior
written permission of TANDBERG ASA. Nationally and internationally recognized trademarks
and tradenames are the property of their respective holders and are hereby acknowledged.
Portions of this software are licensed under 3rd party licenses. See the CD accompanying this
product for details. 3rd party license information may also be obtained from the Gatekeeper itself
— see the license command in section 14.6 for details.
Disclaimer
The information in this document is furnished for informational purposes only, is subject to change
without prior notice, and should not be construed as a commitment by TANDBERG ASA.
The information in this document is believed to be accurate and reliable, however TANDBERG
ASA assumes no responsibility or liability for any errors or inaccuracies that may appear in this
document, nor for any infringements of patents or other rights of third parties resulting from its
use. No license is granted under any patents or patent rights of TANDBERG ASA.
COPYRIGHT c 2006, TANDBERG ASA
i

TANDBERG Gatekeeper User Manual
Environmental Issues
Thank you for buying a product which contributes to a reduction in pollution, and thereby helps
save the environment. Our products reduce the need for travel and transport and thereby reduce
pollution. Our products have either none or few consumable parts (chemicals, toner, gas, paper).
Our products are low energy consuming products.
TANDBERG’s Environmental Policy
Environmental stewardship is important to TANDBERG’s culture. As a global company with strong
corporate values, TANDBERG is committed to being an environmental leader and embracing
technologies that help companies, individuals and communities creatively address environmental
challenges.
TANDBERG’s environmental objectives are to: Develop products that reduce energy consumption,
CO2emissions, and traffic congestion Provide products and services that improve quality of life
for our customers Produce products that can be recycled or disposed of safely at the end of
product life Comply with all relevant environmental legislation.
European Environmental Directives
As a manufacturer of electrical and electronic equipment TANDBERG is responsible for compli-
ance with the requirements in the European Directives 2002/96/EC (WEEE) and 2002/95/EC
(RoHS).
The primary aim of the WEEE Directive and RoHS Directive is to reduce the impact of disposal
of electrical and electronic equipment at end-of-life. The WEEE Directive aims to reduce the
amount of WEEE sent for disposal to landfill or incineration by requiring producers to arrange
for collection and recycling. The RoHS Directive bans the use of certain heavy metals and
brominates flame retardants to reduce the environmental impact of WEEE which is land filled or
incinerated.
TANDBERG has implemented necessary process changes to comply with the European RoHS
Directive (2002/95/EC) and the European WEEE Directive (2002/96/EC).
Waste Handling
In order to avoid the dissemination of hazardous substances in our environment and to diminish
the pressure on natural resources, we encourage you to use the appropriate take-back systems
in your area. Those systems will reuse or recycle most of the materials of your end of life
equipment in a sound way.
ii

TANDBERG Gatekeeper User Manual
TANDBERG products put on the market after August 2005 are marked with a crossed-
out wheelie bin symbol that invites you to use those take-back systems.
Please contact your local supplier, the regional waste administration or
http://www.tandberg.net/recycling if you need more information on the collection
and recycling system in your area.
Information for Recyclers
As part of compliance with the European WEEE Directive, TANDBERG provides recycling
information on request for all types of new equipment put on the market in Europe after August
13th 2005.
Please contact TANDBERG at [email protected] and provide the following details for the
product for which you would like to receive recycling information: Model number of TANDBERG
product Your company’s name Contact name Address Telephone number E-mail address
Digital User Guides
TANDBERG is pleased to announce that we have replaced the printed versions of our User
Guides with a digital CD version. Instead of a range of different user manuals, there is now
one CD — which can be used with all TANDBERG products — in a variety of languages. The
environmental benefits of this are significant. The CDs are recyclable and the savings on paper
are huge. A simple web-based search feature helps you directly access the information you
need. In addition, the TANDBERG video systems now have an intuitive on-screen help function,
which provides a range of useful features and tips. The contents of the CD can still be printed
locally, whenever needed.
iii

TANDBERG Gatekeeper User Manual
Environmental Issues
Thank you for buying a product which contributes to a reduction in pollution, and thereby helps
save the environment. Our products reduce the need for travel and transport and thereby reduce
pollution. Our products have either none or few consumable parts (chemicals, toner, gas, paper).
Our products are low energy consuming products.
TANDBERG’s Environmental Policy
•TANDBERG’s Research and Development is continuously improving TANDBERG’s prod-
ucts towards less use of environmentally hazardous components and substances as well
as to make the products easier to recycle.
•TANDBERG’s products are Communication Solutions. The idea of these solutions is to
reduce the need for expensive, time demanding and polluting transport of people. Through
people’s use of TANDBERG’s products, the environment will benefit from less use of
polluting transport.
•TANDBERG’s wide use of the concepts of outsourcing makes the company itself a company
with a low rate of emissions and effects on the environment.
•TANDBERG’s policy is to make sure our partners produce our products with minimal
influence on the environment and to demand and audit their compatibility according to
applicable agreements and laws (national and international).
Environmental Considerations
Like other electronic equipment, the TANDBERG Gatekeeper contains components that may have
a detrimental effect on the environment. TANDBERG works continuously towards eliminating
these substances in our products.
•Printed-wiring boards made of plastic, with flame-retardants like Chloride or Bromide.
•Component soldering that contains lead.
•Smaller components containing substances with possible environmental effect.
After the product’s end of life cycle, it should be returned to authorized waste handling and should
be treated according to National and International Regulations for waste of electronic equipment.
iv

TANDBERG Gatekeeper User Manual
Operator Safety Summary
For your protection please read these safety instructions completely before you connect the
equipment to the power source. Carefully observe all warnings, precautions and instructions
both on the apparatus and in these operating instructions.
Keep this manual for future reference.
Water and Moisture
•Do not operate the apparatus under or near water – for example near a bathtub, kitchen
sink, or laundry tub, in a wet basement, near a swimming pool or in other areas with high
humidity.
•Never install jacks for communication cables in wet locations unless the jack is specifically
designed for wet locations.
•Do not touch the product with wet hands.
Cleaning
•Unplug the apparatus from communication lines, mains power-outlet or any power source
before cleaning or polishing. Do not use liquid cleaners or aerosol cleaners. Use a lint-free
cloth lightly moistened with water for cleaning the exterior of the apparatus.
•Unplug the apparatus from communication lines before cleaning or polishing. Do not use
liquid cleaners or aerosol cleaners. Use a lint-free cloth lightly moistened with water for
cleaning the exterior of the apparatus.
Ventilation
•Do not block any of the ventilation openings of the apparatus. Never cover the slots and
openings with a cloth or other material. Never install the apparatus near heat sources such
as radiators, heat registers, stoves, or other apparatus (including amplifiers) that produce
heat.
•Do not place the product in direct sunlight or close to a surface directly heated by the sun.
Lightning
•Never use this apparatus, or connect/disconnect communication cables or power cables
during lightning storms.
v

TANDBERG Gatekeeper User Manual
Dust
•Do not operate the apparatus in areas with high concentration of dust.
Vibration
•Do not operate the apparatus in areas with vibration or place it on an unstable surface.
Power connection and Hazardous voltage
•The product may have hazardous voltage inside. Never attempt to open this product, or
any peripherals connected to the product, where this action requires a tool.
•This product should always be powered from an earthed power outlet.
•Never connect attached power supply cord to other products.
•In case any parts of the product has visual damage never attempt to connect mains power,
or any other power source, before consulting service personnel
•The plug connecting the power cord to the product/power supply serves as the main
disconnect device for this equipment. The power cord must always be easily accessible.
•Route the power cord so as to avoid it being walked on or pinched by items placed upon or
against it. Pay particular attention to the plugs, receptacles and the point where the cord
exits from the apparatus.
•Do not tug the power cord
•If the provided plug does not fit into your outlet, consult an electrician. Never install cables,
or any peripherals, without first unplugging the device from it’s power source.
Servicing
•Do not attempt to service the apparatus yourself as opening or removing covers may
expose you to dangerous voltages or other hazards, and will void the warranty. Refer all
servicing to qualified service personnel.
•Unplug the apparatus from it’s power source and refer servicing to qualified personnel
under the following conditions:
–If the power cord or plug is damaged or frayed.
–If liquid has been spilled into the apparatus.
–If objects have fallen into the apparatus.
–If the apparatus has been exposed to rain or moisture
–If the apparatus has been subjected to excessive shock by being dropped.
–If the cabinet has been damaged.
vi

TANDBERG Gatekeeper User Manual
–If the apparatus seems to be overheated.
–If the apparatus emits smoke or abnormal odor.
–If the apparatus fails to operate in accordance with the operating instructions
Accessories
•Use only accessories specified by the manufacturer, or sold with the apparatus.
Communication lines
•Never touch uninstalled communication wires or terminals unless the telephone line has
been disconnected at the network interface.
•Do not use communication equipment to report a gas leak in the vicinity of the leak.
•To reduce the risk of fire, use only No. 26 AWG or larger telecommunication line cord
(ISDN cables).
vii

TANDBERG Gatekeeper User Manual
Contents
1 Introduction 1
1.1 TANDBERG Gatekeeper Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2 Installation 3
2.1 Precautions....................................... 3
2.2 Unpacking........................................ 3
2.3 Mounting ........................................ 4
2.4 ConnectingCables................................... 4
2.5 SwitchingontheSystem................................ 4
2.6 Gatekeeper Initial Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3 Getting started 7
3.1 SystemAdministration................................. 7
3.2 Backups......................................... 8
3.3 IPConfiguration .................................... 8
3.4 Registration....................................... 8
3.5 NeighborGatekeepers................................. 9
3.6 AlternateGatekeepers................................. 11
3.7 Callsignaling...................................... 12
4 Unregistered Endpoints 15
4.1 Calling from an unregistered endpoint . . . . . . . . . . . . . . . . . . . . . . . . 15
4.2 Calling to an unregistered endpoint . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5 Bandwidth Control 17
5.1 Bandwidth Control and Firewall Traversal . . . . . . . . . . . . . . . . . . . . . . 21
5.2 Bandwidth Control Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
6 Registration Control 24
6.1 Registration Restriction Policy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
6.2 Authentication...................................... 25
7 URI Dialing 28
7.1 Making a call using URI dialing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
7.2 Receiving a call using URI dialing . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
7.3 DNSRecords...................................... 29
8 ENUM dialing 31
8.1 ConfiguringENUM................................... 31
8.2 Configuring DNS NAPTR Records . . . . . . . . . . . . . . . . . . . . . . . . . . 31
9 Example Traversal deployments 33
9.1 Simple Enterprise deployment . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
9.2 EnterpriseGatekeepers ................................ 34
9.3 Dialing Public IP addresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
9.4 Neighboredenterprises ................................ 35
9.5 URI dialing from within the enterprise . . . . . . . . . . . . . . . . . . . . . . . . 35
viii

TANDBERG Gatekeeper User Manual
10 Third Party Call Control 37
10.1Placingacall ...................................... 37
10.2Transferringacall.................................... 37
10.3Disconnectingacall .................................. 37
11 Call Policy 39
11.1 Making Decisions Based on Addresses . . . . . . . . . . . . . . . . . . . . . . . 39
11.2CPLScriptActions................................... 41
11.3 Unsupported CPL Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
11.4CPLExamples ..................................... 42
12 Logging 44
12.1 Controlling what is logged . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
12.2Eventlogformat .................................... 44
12.3EventLevels ...................................... 45
12.4LoggedEvents ..................................... 45
12.5RemoteLogging .................................... 49
13 Software Upgrade 50
13.1 Upgrading Using HTTP(S) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
13.2UpgradingUsingSCP ................................. 51
14 Command Reference 53
14.1Status .......................................... 53
14.2Configuration ...................................... 56
14.3Command........................................ 69
14.4History.......................................... 74
14.5Feedback ........................................ 74
14.6Othercommands.................................... 75
A Appendix: Configuring DNS Servers 77
A.1 MicrosoftDNSServer ................................. 77
A.2 VerifyingtheSRVrecord................................ 77
B Appendix: Configuring LDAP Servers 79
B.1 Microsoft Active Directory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
B.2 OpenLDAP ....................................... 80
C Approvals 83
D Technical Specifications 84
E Glossary 87
ix

TANDBERG Gatekeeper User Manual
x

TANDBERG Gatekeeper User Manual
1 Introduction
This User Manual is provided to help you make the best use of your TANDBERG Gatekeeper.
The main features of the TANDBERG Gatekeeper are:
•IPv4 and IPv6 support
•Supports up to 100 neighboring zones.
•Flexible zone configuration with prefix and suffix support.
•Secure firewall traversal of any firewall or NAT when used in conjunction with a TANDBERG
Border Controller.
•Supports up to 2500 registered endpoints.
•Up to 500 concurrent calls.
•Up to 100 traversal calls in conjunction with a TANDBERG Border Controller.
•URI and ENUM dialing with DNS enabling global connectivity.
•Can be used to control the amount of bandwidth used both within the Gatekeeper zone
and to neighboring Border Controllers and Gatekeepers.
•Can limit total bandwidth usage and set maximum per call bandwidth usage with automatic
down-speeding if call exceeds per-call maximum.
•Can be managed with TANDBERG Management Suite 11.0 or newer, or as a standalone
system with RS-232, Telnet, SSH, HTTP and HTTPS.
•Embedded setup wizard on serial port for initial configuration.
Note that features may vary depending on software package.
1

TANDBERG Gatekeeper User Manual
1.1 TANDBERG Gatekeeper Overview
On the front of the Gatekeeper there are three LAN interfaces, a serial port (Data 1) and an LED
showing the power status of the system. The LAN 1 interface is used for connecting the system
to your network, LAN interface 2 and 3 are disabled. The serial port (Data 1) is for connection to
a PC, and power on is indicated by the Light Emitting Diode (Power) being lit.
Figure 1: Front panel of Gatekeeper
The back of the Gatekeeper has a power connector, a power switch, and a serial port (Data 2)
for connecting to a PC.
Figure 2: Rear panel of Gatekeeper
2

TANDBERG Gatekeeper User Manual
2 Installation
2.1 Precautions
•Never install communication equipment during a lightning storm.
•Never install jacks for communication cables in wet locations unless the jack is specifically
designed for wet locations.
•Never touch uninstalled communication wires or terminals unless the communication line
has been disconnected at the network interface.
•Use caution when installing or modifying communication lines.
•Avoid using communication equipment (other than a cordless type) during an electrical
storm.
•There may be a remote risk of electrical shock from lightning.
•Do not use communication equipment to report a gas leak in the vicinity of the leak.
•The socket outlet shall be installed near to the equipment and shall be easily accessible.
•Never install cables without first switching the power OFF.
•This product complies with directives: LVD 73/23/EC and EMC 89/366/EEC.
•Power must be switched off before power supplies can be removed from or installed into
the unit.
2.2 Unpacking
The TANDBERG Gatekeeper is delivered in a special shipping box which should contain the
following components:
•Gatekeeper unit
•Installation sheet
•User manual and other documentation on CD
•Rack-ears and screws
•Kit with 4 rubber feet
•Cables:
–Power cables
–One Ethernet cable
–One null-modem RS-232 cable
3

TANDBERG Gatekeeper User Manual
2.2.1 Installation site preparations
•Make sure that the Gatekeeper is accessible and that all cables can be easily connected.
•For ventilation: Leave a space of at least 10cm (4 inches) behind the Gatekeeper’s rear
and 5cm (2 inches) on the sides.
•The room in which you install the Gatekeeper should have an ambient temperature between
0◦C and 35◦C (32◦F and 95◦F) and between 10% and 90% non-condensing relative
humidity.
•Do not place heavy objects directly on top of the Gatekeeper.
•Do not place hot objects directly on top, or directly beneath the Gatekeeper.
•Use a grounded AC power outlet for the Gatekeeper.
2.3 Mounting
The Gatekeeper comes with brackets for mounting in standard 19” racks.
Before starting the rack mounting, please make sure the TANDBERG Gatekeeper is placed
securely on a hard, flat surface.
1. Disconnect the AC power cable.
2. Make sure that the mounting space is according to the ‘Installation site preparations’ in
section 2.2.1.
3. Attach the brackets to the chassis on both sides of the unit.
4. Insert the unit into a 19” rack, and secure it with screws.
2.4 Connecting Cables
Power cable Connect the system power cable to an electrical distribution socket.
LAN cable Connect a LAN cable from the LAN 1 connector on the front of the unit to your
network.
Null-modem RS-232 cable Connect the supplied null-modem RS-232 cable between the Bor-
der Controller’s Data 1 connector and the COM port on a PC.
2.5 Switching on the System
To start the TANDBERG Gatekeeper, make sure that the following has been done:
•The power cable is connected.
•The LAN cable is connected.
4

TANDBERG Gatekeeper User Manual
Then switch the power switch button on the back of the unit to ‘1’.
On the front of the chassis you will see the Power LED being lit.
2.6 Gatekeeper Initial Configuration
The TANDBERG Gatekeeper requires some configuration before it can be used. This must be
done using a PC connected to the serial port (Data 1) or by connecting to the system’s default
IP address: 192.168.0.100.
The IP address, subnet mask and gateway must be configured before use. The Gatekeeper has
to be configured with a static IP address. Consult your network administrator for information on
which addresses to use.
To set the initial configuration, do the following:
1. Connect the supplied null-modem RS-232 cable from Data 1 to a PC running a terminal
program.
2. Start a terminal program and configure it to use the serial port with baud rate 115200, 8
data bits, no parity, 1 stop bit, no flow control.
3. Power on the unit if it is not already on.
4. You should see the unit display start up information.
5. After approximately 2 minutes you will get a login prompt.
6. Enter username admin and your password. The default password is TANDBERG.
7. You will be prompted if you want to run the install wizard. Type yand press Enter.
(none) login: admin
Password:
Run install wizard [n]: y
8. Specify the following:
(a) The password you want to use for your system. See section 3.1.1 for account details.
(b) The IP address of the system.
(c) The IP subnet mask of the system.
(d) The IP default gateway of the system.
(e) The Ethernet speed.
(f) The local zone prefix, if any, you want to use for the zone controlled by this system.
(g) Whether you want to use SSH to administer the system.
(h) Whether you want to use Telnet to administer the system.
9. You will be prompted to login again. You should see a welcome message like this:
5

TANDBERG Gatekeeper User Manual
Welcome to
TANDBERG Gatekeeper Release N5.0
SW Release Date: 2006-06-15
OK
10. Login with username admin and your password.
11. Review other system settings. You may want to set the following:
(a) The name of the Gatekeeper. This is used to identify the Gatekeeper by the TAND-
BERG Management Suite. See the xConfiguration SystemUnit command in sec-
tion 14.2.18 for more information on setting the name.
(b) Automatic discovery. If you have multiple Gatekeepers in the same network you
may want to disable automatic discovery on some of them. See the xConfiguration
Gatekeeper AutoDiscovery command in section 14.2.4.
(c) The DNS server address and the domain name if the Gatekeeper will be con-
figured with hostnames instead of IP address or if URI dialing is required. See
xConfiguration IP DNS Server Address command in section 14.2.6 for more infor-
mation.
12. Reboot the Gatekeeper by typing the command xCommand boot to make your new settings
take effect.
13. Disconnect the serial cable.
NOTE To securely manage the Gatekeeper you should disable HTTP and Telnet, using the
encrypted HTTPS and SSH protocols instead. For increased security, disable HTTPS and SSH
as well, using the serial port to manage the system.
NOTE If you do not have an IP gateway, configure the Gatekeeper with an unused IP address
that is valid in your subnet.
6

TANDBERG Gatekeeper User Manual
3 Getting started
3.1 System Administration
To configure and monitor the TANDBERG Gatekeeper you can either use the web interface or a
command line interface. The command line interface is available over SSH, Telnet and through
the serial port. By default administration sessions remain active until you logout. Session
timeouts may be enabled using the xConfiguration Session TimeOut command.
To enter commands you should start a session and login with user name admin and your
password.
The interface groups information in different commands:
xstatus Provides a read only interface to determine the current status of the system. Information
such as current calls and registrations is available through this command group.
xconfiguration A read/write interface to set system configuration data such as IP address and
subnet.
xcommand A miscellaneous group of commands for setting information or obtaining it.
xhistory Provides historical information about calls and registrations.
xfeedback An event interface, providing information about calls and registrations.
A command reference is given in section 14.
3.1.1 Administrator Account
All administration requires you to log in to the administration account with a user name admin
and a password. The default password is TANDBERG, which you are recommended to change
as soon as possible. Choose a strong password, particularly if administration over IP is enabled.
The password can be changed on the web page System Configuration →System or through the
command line interface using the command:
xconfiguration systemunit password: new password
If you forget your password, it is possible to set a new password using the following procedure:
•Reboot the Gatekeeper.
•Connect to the Gatekeeper over the serial interface once it has restarted.
•Login with the user name pwrec. No password is required.
•You will be prompted for a new password.
The pwrec account is only active for one minute following a restart. Beyond that time you will
have to restart the system again to change the password. Because access to the serial port
allows the password to be reset, it is recommended that you install the Gatekeeper in a physically
secure environment.
7

TANDBERG Gatekeeper User Manual
3.1.2 Root Account
The Gatekeeper provides a root account with the same password as the admin account. This
account should not be used in normal operation, and in particular system configuration should
not be conducted using this account: use the admin account instead.
3.2 Backups
You are recommended to maintain a backup of your Gatekeeper configuration. Using the
command line interface, log on to the Gatekeeper as admin and type xConfiguration. Save the
resulting output to a file, using cut-and-paste or some other means provided by your terminal
emulator. Pasting this information back in to the command line shell will restore your configuration.
3.3 IP Configuration
The Gatekeeper may be configured to use IPv4, IPv6 or both protocols. If using both protocols,
the Gatekeeper will act as a gateway if necessary, allowing calls to be made between an IPv4
only endpoint and an IPv6 only endpoint. This behavior will use a traversal license for each call
gatewayed between IPv4 and IPv6.
IPv4 and IPv6 dual stack behavior is controlled by the command
xConfiguration IPProtocol: <Both/IPv4/IPv6>
or using the web page System Configuration →IP shown in figure 3
3.4 Registration
Before an endpoint can use the Gatekeeper it must first register with it. There are two ways an
endpoint can register:
•Automatically.
•Manually by specifying the IP address of the Gatekeeper.
You can disable automatic registration on the Gatekeeper. See auto discovery in section 14.2 for
more information.
When registering, the endpoint registers with one or more of the following:
•One or more H.323 IDs.
•One or more E.164 aliases.
Users of other registered endpoints can then call the endpoint by using either the H.323 ID, a
URI, an E.164 alias, or one of the services.
It is recommended that you do not use aliases that reveal sensitive information. Due to the nature
of H.323, call setup information is exchanged in an unencrypted form.
8

TANDBERG Gatekeeper User Manual
Figure 3: Selecting IP Protocol
By default,if you attempt to register an alias which has already been registered with the system,
your registration will be rejected. This helps you to identify when two users have a conflicting alias.
In some deployments an endpoint may frequently receive a new IP address, causing unwanted
registration rejections. When it tries to register, it may be rejected because the Gatekeeper
still has a registration from its old IP address. The Gatekeeper may be configured to allow an
endpoint to overwrite the old IP address with the command:
xConfiguration Gatekeeper Registration ConflictMode: <Overwrite/Reject>
Consult the endpoint documentation for information on how to configure it with a Gatekeeper.
NOTE When URI dialing is used to discover an endpoint, the URI used is based on either the
H.323 ID or the E.164 alias that the endpoint registered with. The local domain is then added to
this. For more information on URI dialing see section 7
3.5 Neighbor Gatekeepers
As you start deploying more than one Gatekeeper or Border Controller, it is useful to neighbor
the systems together so that they can exchange information about registered endpoints. Each
Gatekeeper or Border Controller forms an H.323 zone and is responsible for the endpoints within
that zone.
The simplest approach is to assign each endpoint a unique alias and divide the endpoint
registrations between the Gatekeepers and Border Controllers. Each Gatekeeper or Border
Controller is then configured with the addresses of all other Gatekeepers and Border Controllers.
When a system receives a call for an endpoint which is not registered with, it will send out a
9