VoIP with Gatekeeper

Available Languages

Download Options

PDF (50.9 KB)
View with Adobe Reader on a variety of devices

Updated:March 30, 2006

Document ID:14084

Bias-Free Language

The documentation set for this product strives to use bias-free language. For the purposes of this documentation set, bias-free is defined as language that does not imply discrimination based on age, disability, gender, racial identity, ethnic identity, sexual orientation, socioeconomic status, and intersectionality. Exceptions may be present in the documentation due to language that is hardcoded in the user interfaces of the product software, language used based on RFP documentation, or language that is used by a referenced third-party product. Learn more about how Cisco is using Inclusive Language.

Introduction

Prerequisites

Requirements

Components Used

Conventions

Background Information

Configure

Network Diagram

Call Process

Configurations

Verify

Verification for Raleigh 5300A Router

Verification for Raleigh 3640A Router

Verification for San Jose 5300A Router

Verification for San Jose 3640A Router

Gatekeeper Call Information

Troubleshoot

Troubleshooting Commands

Related Information

Introduction

This document illustrates how to configure and verify a VoIP network with a gatekeeper.

Prerequisites

Requirements

There are no specific requirements for this document.

Components Used

The information in this document is based on these software and hardware versions:

Cisco IOS® Software Release 12.1(1)
Cisco AS5300 and Cisco 3640 routers

Note: There is a requirement to load Cisco IOS feature set –x– for the gatekeeper functionality on all Cisco platforms.

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.

Conventions

For more information on document conventions, refer to the Cisco Technical Tips Conventions .

Background Information

A gatekeeper is an H.323 entity on a LAN that provides address translation and control access to the LAN for H.323 terminals and gateways. The gatekeeper can provide other services to the H.323 terminals and gateways, such as bandwidth management and the location of gateways. A gatekeeper maintains a registry of devices in the multimedia network. The devices register with the gatekeeper at startup and request admission to a call from the gatekeeper.

You can use the gatekeeper configuration in this document for these purposes:

To help scale a VoIP implementation where you have installed several gateways and end devices

This configuration allows changes to be made at a central point, the gatekeeper.
To help control Call Admission Control (CAC) in order to limit the number of calls on the network
To implement the use of a proxy on the network to handle your VoIP calls separately from your data traffic

Configure

In this section, you are presented with the information to configure the features described in this document.

Note: To find additional information on the commands used in this document, use the Command Lookup Tool (registered customers only) .

Network Diagram

This network is a simple topology with two Cisco AS5300 gateways. One gateway is in San Jose, and the other gateway is in Raleigh. At each site, there is a gatekeeper configuration that runs on a Cisco 3640. In the topology that this section shows, a gatekeeper is not really necessary in order to place simple VoIP calls between the two gateways. But the diagram includes a gatekeeper in order to show how the complete configuration looks.

The Cisco gatekeeper configurations for this topology differ from a regular VoIP implementation in these ways:

Each gateway for the gateway setup registers with the local gatekeeper with use of the h323–gateway voip interface commands. In this case, the gateways are AS5300s, and the gatekeeper is the 3640.
The session target in the dial–peer voice 2 voip command points to Registration, Admission, and Status (RAS) instead of the appropriate ipv4:ip address . RAS performs these tasks:
- Defines the location for the gateway to register with the gatekeeper
- Sends admission requests for each call
- Conducts certain status information polling for calls

In the H.323 network, you have one primary gatekeeper per zone. The gatekeeper can control multiple gateways or end H.323 devices in the zone. In the configuration that this section illustrates, a call routes to the appropriate zone and gatekeeper. Then, the gatekeeper replies to the call request with the IP address of the registered gateway that has the technology prefix (tech–prefix) that matches the called number.

Call Process

These steps explain how the gatekeeper process works. A phone on the Raleigh side places a call to a phone on the San Jose side:

Raleigh 5300A receives a call from the PBX to 4085556400, which is a phone that connects to the San Jose PBX.

This number matches the number under the dial–peer voice 2 voip and also has a technology prefix of 408#.
The admission request to the Raleigh gatekeeper, Raleigh 3640A, includes the technology prefix and called number in the format 408#4085556400.

The 4085556400 matches the zone prefix command of 408.......
The Raleigh gatekeeper sends a location request to the San Jose gatekeeper, San Jose 3640A.
Because the San Jose gatekeeper configuration contains San Jose 5300A with a technology prefix of 408#, the San Jose gatekeeper replies to the Raleigh gatekeeper with the San Jose 5300 IP address.
This IP address forwards to Raleigh 5300A via an Admission Confirmation (ACF).
Raleigh 5300A opens a normal H.323 call with San Jose 5300A.

Configurations

This document uses these configurations:

Raleigh 5300A
Raleigh 3640A
San Jose 5300A
San Jose 3640A

Raleigh 5300A
Raleigh5300A# show run Building configuration... Current configuration: ! ! Last configuration change at 00:15:38 UTC Tue Mar 28 2000 ! NVRAM config last updated at 00:15:39 UTC Tue Mar 28 2000 ! version 12.1 service timestamps debug datetime msec service timestamps log datetime msec no service password–encryption ! hostname Raleigh5300A ! logging buffered 50000 debugging enable secret < password > [Choose a strong password with at least one capital letter, one number, and one special character.] ! ! ! resource–pool disable ! ! ! ! ! clock calendar–valid ip subnet–zero ! isdn switch–type primary–5ess isdn voice–call–failure 0 mta receive maximum–recipients 0 ! ! controller T1 0 framing esf clock source line primary linecode b8zs pri–group timeslots 1–24 ! controller T1 1 clock source line secondary 1 ! controller T1 2 ! controller T1 3 ! ! voice–port 0:D ! ! dial–peer voice 1 pots answer–address 9195552001 destination–pattern 919#9195552... direct–inward–dial port 0:D prefix 919 ! dial–peer voice 2 voip destination–pattern 4085556400 tech–prefix 408# session target ras ! num–exp 6... 4085556... gateway ! interface Ethernet0 no ip address shutdown ! interface Serial0:23 no ip address ip mroute–cache isdn switch–type primary–5ess isdn incoming–voice modem fair–queue 64 256 0 no cdp enable ! interface FastEthernet0 ip address 172.16.120.2 255.255.255.0 duplex auto speed auto h323–gateway voip interface h323–gateway voip id RALgk1 ipaddr 172.16.120.1 1718 h323–gateway voip h323–id RAL5300A@cisco.com h323–gateway voip tech–prefix 919# ! ip classless ip route 172.16.110.0 255.255.255.0 172.16.120.10 no ip http server ! line con 0 transport input none line 1 48 transport output lat pad telnet rlogin udptn v120 lapb–ta line aux 0 line vty 0 4 password cisco login ! ntp clock–period 17179850 ntp server 172.16.110.10 end

Raleigh 5300A

Raleigh5300A# show run
Building configuration...


Current configuration:
!
! Last configuration change at 00:15:38 UTC Tue Mar 28 2000
! NVRAM config last updated at 00:15:39 UTC Tue Mar 28 2000
!
version 12.1
service timestamps debug datetime msec
service timestamps log datetime msec
no service password–encryption
!
hostname Raleigh5300A
!
logging buffered 50000 debugging
enable secret < password > [Choose a strong password with at least one capital letter, one number, and one special character.]
!
!
!
resource–pool disable
!
!
!
!
!
clock calendar–valid
ip subnet–zero
!
isdn switch–type primary–5ess
isdn voice–call–failure 0
mta receive maximum–recipients 0
!
!
controller T1 0
 framing esf
 clock source line primary
 linecode b8zs
 pri–group timeslots 1–24
!
controller T1 1
 clock source line secondary 1
!
controller T1 2
!
controller T1 3
!
!
voice–port 0:D
!
!
dial–peer voice 1 pots
 answer–address 9195552001
 destination–pattern 919#9195552...
 direct–inward–dial
 port 0:D
 prefix 919
!
dial–peer voice 2 voip
 destination–pattern 4085556400
 tech–prefix 408#
 session target ras
!
num–exp 6... 4085556...
 gateway 

  !
  interface Ethernet0
  no ip address
  shutdown
!
interface Serial0:23
 no ip address
 ip mroute–cache
 isdn switch–type primary–5ess
 isdn incoming–voice modem
 fair–queue 64 256 0
 no cdp enable
!
interface FastEthernet0
 ip address 172.16.120.2 255.255.255.0
 duplex auto
 speed auto
 h323–gateway voip interface
 h323–gateway voip id RALgk1 ipaddr 172.16.120.1 1718
 h323–gateway voip h323–id RAL5300A@cisco.com
 h323–gateway voip tech–prefix 919#
!
ip classless
ip route 172.16.110.0 255.255.255.0 172.16.120.10
no ip http server
!
line con 0
 transport input none
line 1 48
 transport output lat pad telnet rlogin udptn v120 lapb–ta
line aux 0
line vty 0 4
 password cisco
 login
!
ntp clock–period 17179850
ntp server 172.16.110.10
end

Raleigh 3640A
Raleigh3640A# show run Building configuration... Current configuration: ! version 12.1 service timestamps debug datetime msec service timestamps log datetime msec no service password–encryption ! hostname Raleigh3640A ! logging buffered 50000 debugging enable secret < password > [Choose a strong password with at least one capital letter, one number, and one special character.] ! ! ! ! ! ip subnet–zero ! ip dvmrp route–limit 20000 ! ! ! ! ! interface Ethernet1/0 ip address 172.16.120.1 255.255.255.0 ! interface Serial1/0 no ip address no ip mroute–cache no fair–queue ! interface TokenRing1/0 no ip address shutdown ring–speed 16 ! ip classless ip route 172.16.110.0 255.255.255.0 172.16.120.10 no ip http server ! ! gatekeeper zone local RALgk1 cisco.com zone remote SJgk1 cisco.com 172.16.110.1 1719 zone prefix SJgk1 408....... gw–type–prefix 408#* no shutdown ! ! line con 0 transport input none line aux 0 line vty 0 4 password cisco login ! ntp clock–period 17179864 ntp server 172.16.110.10 end

Raleigh 3640A

Raleigh3640A# show run
Building configuration...


Current configuration:
!
version 12.1
service timestamps debug datetime msec
service timestamps log datetime msec
no service password–encryption
!
hostname Raleigh3640A
!
logging buffered 50000 debugging
enable secret < password > [Choose a strong password with at least one capital letter, one number, and one special character.]
!
!
!
!
!
ip subnet–zero
!
ip dvmrp route–limit 20000
!
!
!
!
!
interface Ethernet1/0
 ip address 172.16.120.1 255.255.255.0
!
interface Serial1/0
 no ip address
 no ip mroute–cache
 no fair–queue
!
interface TokenRing1/0
 no ip address
 shutdown
 ring–speed 16
!
ip classless
ip route 172.16.110.0 255.255.255.0 172.16.120.10
no ip http server
!
!
gatekeeper
 zone local RALgk1 cisco.com
 zone remote SJgk1 cisco.com 172.16.110.1 1719
 zone prefix SJgk1 408.......
 gw–type–prefix 408#*
 no shutdown
!
!
line con 0
 transport input none
line aux 0
line vty 0 4
 password cisco
 login
!
ntp clock–period 17179864
ntp server 172.16.110.10
end

San Jose 5300A
SanJose5300A# show run Building configuration... Current configuration: ! ! Last configuration change at 00:15:49 UTC Tue Mar 28 2000 ! NVRAM config last updated at 00:15:50 UTC Tue Mar 28 2000 ! version 12.1 service timestamps debug datetime msec service timestamps log datetime msec no service password–encryption ! hostname SanJose5300A ! logging buffered 50000 debugging enable secret < password > [Choose a strong password with at least one capital letter, one number, and one special character.] ! ! ! resource–pool disable ! ! ! ! ! ip subnet–zero ! isdn voice–call–failure 0 mta receive maximum–recipients 0 ! ! controller T1 0 framing esf clock source line primary linecode b8zs ds0–group 1 timeslots 1–4 type e&m–immediate–start ! controller T1 1 clock source line secondary 1 ! controller T1 2 ! controller T1 3 ! ! voice–port 0:1 ! ! dial–peer voice 1 pots answer–address 4085556001 destination–pattern 408#4085556... direct–inward–dial port 0:1 prefix 6 ! dial–peer voice 2 voip destination–pattern 9195552... tech–prefix 919# session target ras ! num–exp 2... 9195552... gateway ! interface Ethernet0 no ip address ! interface FastEthernet0 ip address 172.16.110.2 255.255.255.0 duplex auto speed auto h323–gateway voip interface h323–gateway voip id SJgk1 ipaddr 172.16.110.1 1718 h323–gateway voip h323–id SJ5300A@cisco.com h323–gateway voip tech–prefix 408# ! ip classless ip route 172.16.120.0 255.255.255.0 172.16.110.10 no ip http server ! ! ! line con 0 transport input none line aux 0 line vty 0 4 password cisco login ! ntp clock–period 17179892 ntp server 172.16.110.10 end

San Jose 5300A

SanJose5300A# show run
Building configuration...


Current configuration:
!
! Last configuration change at 00:15:49 UTC Tue Mar 28 2000
! NVRAM config last updated at 00:15:50 UTC Tue Mar 28 2000
!
version 12.1
service timestamps debug datetime msec
service timestamps log datetime msec
no service password–encryption
!
hostname SanJose5300A
!
logging buffered 50000 debugging
enable secret < password > [Choose a strong password with at least one capital letter, one number, and one special character.]
!
!
!
resource–pool disable
!
!
!
!
!
ip subnet–zero
!
isdn voice–call–failure 0
mta receive maximum–recipients 0
!
!
controller T1 0
 framing esf
 clock source line primary
 linecode b8zs
 ds0–group 1 timeslots 1–4 type e&m–immediate–start
!
controller T1 1
 clock source line secondary 1
!
controller T1 2
!
controller T1 3
!
!
voice–port 0:1
!
!
dial–peer voice 1 pots
 answer–address 4085556001
 destination–pattern 408#4085556...
 direct–inward–dial
 port 0:1
 prefix 6
!
dial–peer voice 2 voip
 destination–pattern 9195552...
 tech–prefix 919#
 session target ras
!
num–exp 2... 9195552...
gateway 
 
 !
 interface Ethernet0
 no ip address
!
interface FastEthernet0
 ip address 172.16.110.2 255.255.255.0
 duplex auto
 speed auto
 h323–gateway voip interface
 h323–gateway voip id SJgk1 ipaddr 172.16.110.1 1718
 h323–gateway voip h323–id SJ5300A@cisco.com
 h323–gateway voip tech–prefix 408#
!
ip classless
ip route 172.16.120.0 255.255.255.0 172.16.110.10
no ip http server
!
!
!
line con 0
 transport input none
line aux 0
line vty 0 4
 password cisco
 login
!
ntp clock–period 17179892
ntp server 172.16.110.10
end

San Jose 3640A
SanJose3640A# show run Building configuration... Current configuration: ! ! NVRAM config last updated at 00:05:33 UTC Tue Mar 28 2000 ! version 12.1 service timestamps debug datetime msec service timestamps log datetime msec no service password–encryption ! hostname SanJose3640A ! boot system flash c3640–ix–mz.120–7.T logging buffered 50000 debugging enable secret < password > [Choose a strong password with at least one capital letter, one number, and one special character.] ! ! ! ! ! ip subnet–zero ! ip dvmrp route–limit 20000 ! ! interface Ethernet1/0 ip address 172.16.110.1 255.255.255.0 ! interface Serial1/0 no ip address no ip mroute–cache shutdown no fair–queue ! interface Ethernet1/1 no ip address shutdown ! ip classless ip route 172.16.120.0 255.255.255.0 172.16.110.10 no ip http server ! tftp–server flash:c3640–ix–mz.121–1.bin ! gatekeeper zone local SJgk1 cisco.com zone remote RALgk1 cisco.com 172.16.120.1 1719 zone prefix RALgk1 919....... gw–type–prefix 919#* no shutdown ! ! line con 0 transport input none line aux 0 line vty 0 4 password cisco login ! ntp server 172.16.110.10 end

San Jose 3640A

SanJose3640A# show run
Building configuration...


Current configuration:
!
! NVRAM config last updated at 00:05:33 UTC Tue Mar 28 2000
!
version 12.1
service timestamps debug datetime msec
service timestamps log datetime msec
no service password–encryption
!
hostname SanJose3640A
!
boot system flash c3640–ix–mz.120–7.T
logging buffered 50000 debugging
enable secret < password > [Choose a strong password with at least one capital letter, one number, and one special character.] 
!
!
!
!
!
ip subnet–zero
!
ip dvmrp route–limit 20000
!
!
interface Ethernet1/0
 ip address 172.16.110.1 255.255.255.0
!
interface Serial1/0
 no ip address
 no ip mroute–cache
 shutdown
 no fair–queue
!
interface Ethernet1/1
 no ip address
 shutdown
!
ip classless
ip route 172.16.120.0 255.255.255.0 172.16.110.10
no ip http server
!
tftp–server flash:c3640–ix–mz.121–1.bin
!
gatekeeper
 zone local SJgk1 cisco.com
 zone remote RALgk1 cisco.com 172.16.120.1 1719
 zone prefix RALgk1 919.......
 gw–type–prefix 919#*
 no shutdown
!
!
line con 0
 transport input none
line aux 0
line vty 0 4
 password cisco
 login
!
ntp server 172.16.110.10
end