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Cisco Unified Communications Manager (CallManager)

Configuring an Anonymous Device Gatekeeper with Cisco CallManager Versions 3.3 and 4.1

Introduction

This document explains how to set up an anonymous device gatekeeper with use of a Cisco CallManager 4.1 or 3.3 server. It requires the use of a Cisco IOS® Software router to act as a gatekeeper and a Cisco IOS router to act as an H.323 gateway. The primary focus of this document is on how to configure the Cisco CallManager 4.1 or 3.3 server to use a gatekeeper. After you finish this configuration, you can make calls in either direction with Call Admission Control (CAC) between an IP phone registered to the Cisco CallManager 4.1 or 3.3 server and an analog phone attached to the Cisco IOS gateway.

Prerequisites

Requirements

Before you attempt this configuration, ensure that you meet these requirements:

  • You have a sample network with a Cisco CallManager server.

  • You have an IP phone (model 7910, 7940, or 7960).

  • You have a Cisco IOS gateway with an Foreign Exchange Station (FXS) port.

  • You have an analog phone that is attached to the FXS port on the Cisco IOS gateway.

  • You have a Cisco IOS router with an image that supports H.323 gatekeeper functionality.

  • All devices can ping each other.

  • The IP phone can call the analog phone with two-way voice capability.

  • The analog phone can call the IP phone with two-way voice capability.

Note: For more information, see the Network Diagram in this document.

Components Used

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

  • Cisco IOS router that acts as an H.323 VoIP gateway and runs Cisco IOS Software Release 12.2(11)T

  • Cisco IOS router that acts as an H.323 VoIP gatekeeper and runs Cisco IOS Software Release 12.2(15)T

  • Cisco CallManager server that runs 4.1(.091) or 3.3(3)sr4a

  • 7960 IP Phone

  • Generic analog phone

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 Theory

An anonymous device gatekeeper handles call-route decisions for the Cisco IOS gateways and Cisco CallManager gateways that are registered to it. This means that the Cisco CallManager servers in the cluster do not need to know about every other gateway in the network. Instead, their route patterns or VoIP dial peers are configured to point to the anonymous device gatekeeper. The anonymous device gatekeeper keeps track of the dial plan for the network. Refer to the document Understanding Cisco IOS Gatekeeper Call Routing for additional information on this subject.

Networks used to learn internetwork skills typically use the configuration presented in this document. The concepts and commands are the same ones that you encounter in a live environment. The primary difference is that this scenario does not have a WAN connection for VoIP traffic that benefits from CAC.

Note: In Cisco CallManager 4.1 and 3.3, trunks replace all previously configured intercluster trunk devices. An H.225 trunk device represents a logical route to the wholesale network. Previously configured anonymous devices with H.225 protocol migrate to H.225 trunks with gatekeeper control. Previously configured anonymous devices with intercluster protocol migrate to intercluster trunks with gatekeeper control. Previously configured intercluster gateways migrate to intercluster trunks without gatekeeper control.

The successful implementation of CAC requires a well thought-out network design and CAC overlay that corresponds to it. A complete explanation of how to design and implement a CAC solution—which includes all of the available options to implement CAC on Cisco IOS gateways and gatekeepers—is beyond the scope of this document. There are several good resources available on Cisco.com to help you understand and implement CAC with Cisco IOS Software-based gateways and gatekeepers. Search for gatekeeper on Cisco.com. You can then filter your search with additional words, such as troubleshooting or understanding. You can also limit the scope of your search to Products and Services or Technical Support (content written by Technical Support only).

Network Diagram

This document uses this network setup:

ccma_with_gk1.gif

Configure the Cisco CallManager Gatekeeper Parameters

This section explains how to create an instance of an anonymous device gatekeeper in Cisco CallManager.

Step-by-Step Instructions

  1. Choose Device > Gatekeeper.

    The Find and List Gatekeeper Configuration window displays.

  2. In the upper, right corner of the window, click the Add a New Gatekeeper link.

    The Gatekeeper Configuration window displays.

    Note: If a gatekeeper already exists, you may want to delete it and start over. This ensures that you start with the default values for any parameters that this section does not specifically mention.

  3. Enter these parameters:

    Parameter Setting
    Host Name/IP Address Enter the IP address or host name of the gatekeeper in this required field. You can register multiple gatekeepers for each Cisco CallManager cluster. In this case, it is 10.89.129.228.
    Description Enter a descriptive name for the gatekeeper. In this case, it is psy-gk-01.
    Enable Device Ensure that the check box for this field is checked. This allows you to register this gatekeeper with Cisco CallManager. By default, this check box remains checked.

    The parameter page appears as shown:

    ccma_with_gk2.gif

  4. Click Insert or Update, as indicated.

Configure the H.225 Trunk Parameters

This section explains how to configure an H.225 trunk device that represents a logical route to the wholesale network.

Step-by-Step Instructions

  1. Choose Device > Trunk.

  2. Choose Add a New Trunk.

  3. In the Trunk type field, click the drop-down arrow and choose H.225 Trunk (Gatekeeper Controlled).

  4. In the Device Protocol field, click the drop-down arrow and choose H.225, as shown here:

    ccma_with_gk3.gif

  5. For Cisco CallManager 4.1, complete these steps.

    Note: For Cisco CallManager 3.3, move on to Step 6.

    1. Leave the other fields set to their defaults, and click Next.

      The Trunk Configuration window appears.

    2. Enter these parameters:

      Parameter Setting
      Device Name Enter a unique identifier for the trunk. In this case, it is h225_trk.
      Description Enter a descriptive name for the trunk.
      Device Pool Choose the appropriate device pool for the trunk. In this case, it is Default.
      Gatekeeper Name Choose the gatekeeper IP address that controls this trunk. In this case, it is 10.89.129.228.
      Terminal Type Choose Gateway.
      Technology Prefix Enter 1#* in this field.
      Zone Enter the appropriate zone. In this case, the zone used is horse.

      The parameter page appears as shown:

      ccma_with_gk4.gif

    3. Skip Step 6 and move on to Step 7.

  6. For Cisco CallManager 3.3, enter the parameters listed in this table.

    Note: The only difference between Cisco CallManager 4.x and 3.3 in this regard is the addition of the parameters Calling Party Selection and Calling Line ID Presentation.

    Parameter Setting
    Device Name Enter a unique identifier for the trunk. In this case, it is h225_trk.
    Description Enter a descriptive name for the trunk.
    Device Pool Choose the appropriate device pool for the trunk. In this case, it is Default.
    Calling Party Selection Choose Originator.
    Calling Line ID Presentation Choose Default.
    Gatekeeper Name Choose the gatekeeper IP address that controls this trunk. In this case, it is 10.89.129.228.
    Terminal Type Choose Gateway.
    Technology Prefix Enter 1#* in this field.
    Zone Enter the appropriate zone. In this case, the zone used is horse.

  7. Click Update, and click Reset Trunk.

Change the Route Pattern to Use the Cisco CallManager Gatekeeper

This section explains how to point a route pattern at a gatekeeper (which, in this case, is the anonymous device gatekeeper) rather than at a gateway or route list.

Step-by-Step Instructions

  1. Choose Route Plan > Route/Hunt > Route Pattern.

  2. Click Find.

  3. Click the Route Pattern that you have configured to route calls to the analog phone.

    In this case, it is the route pattern for extension 2000.

  4. In the Gateway/Route List field, click the drop-down arrow and choose h225_trk.

    This is the trunk you just created.

    Note: If your previous configuration allowed calls from your IP phone to your analog phone (as mentioned in the Requirements section of this document), you should not need to make any further changes. Set the remainder of the parameters for the route pattern, as shown in this window, to values that are known to work for the scenario of this document:

    ccma_with_gk5.gif

  5. Click Update.

Configure the Gatekeeper Parameters

This section explains how to configure the Cisco IOS gatekeeper parameters required for CAC.

Use this configuration for the Cisco gatekeeper:

!
!
gatekeeper
 zone local horse maui-onions.com 10.89.129.228
 zone prefix horse 2* gw-priority 10 10.89.129.211
 zone prefix horse 2* gw-priority 0 10.89.129.226
 gw-type-prefix 1#* default-technology
 bandwidth total zone horse 256
 no shutdown
!
!

Notes for This Configuration

  • The gatekeeper controls the zone named horse. This is why it is configured as a local zone. The IP address is a local address that is used as the source address for CAC IP packets from the gatekeeper.

  • The zone prefix commands for the horse zone are the dial plan for this zone. This is how the gatekeeper associates dialed numbers with the correct zone.

    A priority of 1 or higher indicates that a gateway is a viable path to route calls to the prefix configured. A priority of 0 indicates that a gateway is not a viable path to route calls to the prefix configured.

    A complete explanation of how gatekeepers make route decisions is beyond the scope of this document. Refer to the document Understanding Cisco IOS Gatekeeper Call Routing for more information on how gatekeepers make call-route decisions.

  • In this scenario, you do not prepend technology prefixes to the dialed digits when the calls are routed to the gatekeeper. This is why the gatekeeper requires the gw-type-prefix 1#* default-technology command and the Cisco IOS gateway requires the h323-gateway voip tech-prefix 1# command as well as the Technology Prefix 1#* parameter on the Cisco CallManager gatekeeper configuration. If you neglect to meet these configuration requirements, calls do not complete successfully.

  • This zone has a total bandwidth capacity of 256 kbps.

    Note: There are two versions of the command to set the bandwidth for a zone, which depends on the version of Cisco IOS Software you run on the gatekeeper. The command versions are bandwidth total zone and zone bw.

Configure the Gateway Parameters

This section explains how to configure the Cisco IOS gateway parameters required for CAC.

Use this configuration for the Cisco gateway:

!
interface Ethernet0/0
 ip address 10.89.129.226 255.255.255.240
 full-duplex
 h323-gateway voip interface
 h323-gateway voip id horse ipaddr 10.89.129.228 1719
 h323-gateway voip h323-id psy-voice-01@maui-onions.com
 h323-gateway voip tech-prefix 1#
 h323-gateway voip bind srcaddr 10.89.129.226
!
voice-port 1/0/0
!
voice-port 1/0/1
!
dial-peer voice 1 pots
 destination-pattern 2000
 port 1/0/1
!
dial-peer voice 2 voip
 destination-pattern 1...
 session target ras
!
gateway
!

Notes for This Configuration

  • In this scenario, you do not prepend technology prefixes to the dialed digits when the calls are routed to the gatekeeper. This is why the Cisco IOS gateway requires the command h323-gateway voip tech-prefix 1# and the gatekeeper requires the command gw-type-prefix 1#* default-technology as well as the Technology Prefix 1#* parameter on the Cisco CallManager gatekeeper configuration. If you neglect to meet these configuration requirements, calls do not complete successfully.

  • You must include the gateway command. The other parameters that you can apply under the gateway command are optional.

  • The session target ras command on the gateway causes it to route calls to 1006 (the Directory Number [DN] of the IP phone) to the gatekeeper with the destination-pattern 1... wildcard.

  • The h323-gateway voip h323-id command provides a unique identifier for this gateway that appears in the show gatekeeper endpoints command on the gatekeeper.

  • The voice port 1/0 in the Cisco IOS gateway is an FXS port. The destination pattern (2000) under POTS dial peer registers as an E.164 (ITU-T) ID with the gatekeeper. You can see this in the output of the show gatekeeper endpoints command on the gatekeeper.

Verify

This section provides some of the basic commands available to verify that your gatekeeper configuration works properly. There are several other documents on Cisco.com that explain how to verify and troubleshoot gatekeeper configurations in greater detail. See the Related Information