Discovery 12: Implement PSTN Calling Using MGCP Gateways

Introduction
Implementing PSTN calling using MGCP gateways is a complex task that includes configuration on both Cisco
Unified Communications Manager and the Cisco IOS gateway.

You will configure Cisco Unified Communications Manager (HQ-UCM) and Cisco IOS gateway to support MGCP.
Then you will troubleshoot MGCP registration and verify your configuration. You will also implement inbound and
outbound PSTN calling by creating a dial plan and a digit manipulation configuration on Cisco Unified
Communications Manager. You will then implement the local gateway selection feature to implement PSTN calls.

There are three Cisco IP Communicator phones. One is located on PC-1 (CIPC-1), one on PC-2 (CIPC-2), and one
on PC-3 (PSTN). The CIPC-1 and CIPC-2 phones are preconfigured in HQ-CUCM. CIPC-1 is located in the San
Jose (SJC) location and CIPC-2 is located in the Research Triangle Park (RTP) location. You do not have access
to the RTP-GW and PSTN-GW. They are preconfigured with all the necessary commands to perform this lab.

Cisco Unified Communications Manager Express (Cisco Unified CME) is preconfigured on the PSTN-GW to accept
register messages from PSTN phone. The PSTN phone can be reached from:
SJC location through the San Jose gateway (SJC-GW) by:

Local calls from CIPC-1 (408[2-9]XXXXXX), the SJC local line

National calls (1[2-9]XXXXXX), the SJC national line
International calls (011!), the SJC international line
Emergency calls (911), the SJC emergency line

RTP location through the RTP gateway (RTP-GW) by:

Local calls from CIPC-2 (919[2-9]XXXXXX), the RTP local line

By national calls (1[2-9]XXXXXX), the RTP national line
By international calls (011!), the RTP international line
By emergency calls (911), the RTP emergency line

The connections between SJC-GW and the PSTN-GW and between RTP-GW and the PSTN-GW are ISDN links.
The connection between HQ-UCM and RTP-GW is a SIP trunk, which is preconfigured on both sides of the trunk.

This lab will take approximately 90 minutes to complete.

Topology

Job Aid
Device Information

Device Description IP Address Credentials

PC-1 PC running Cisco IP Communicator HQ-CIPC-1 10.1.5.200 Student, C0ll@B

PC-2 PC running Cisco IP Communicator HQ-CIPC-2 10.1.5.201 Student, C0ll@B

PC-3 PC running Cisco IP Communicator PSTN 10.1.99.101 Student, C0ll@B

HQ-UCM Cisco Unified Communications Manager 10.1.5.5 Administrator, C0ll@B

Device Description IP Address Credentials

SJC-GW Router 10.1.5.252 Administrator, C0ll@B

Command List
The table describes the commands that are used in this activity. The commands are listed in alphabetical order so
that you can easily locate the information that you need. Refer to this list if you need configuration command
assistance during the lab activity.

Command Description

This command displays information about call setup and teardown of ISDN network connections (Layer 3) between
debug isdn q931
the local router (user side) and the network.

ccm-manager This command specifies the TFTP server from which the MGCP gateway downloads Cisco Unified Communications
config Manager XML configuration files, and enables download of the configuration.

ccm-manager This command configures the IP address or logical name of the TFTP server from which the XML configuration files
config server are downloaded.

mgcp This command enables MGCP application on the gateway.

show mgcp This command displays values for MGCP parameters.

show mgcp
This command displays a list of all MGCP endpoints on an MGCP gateway.
endpoint

show ccm-manager This command displays the registration status of the MGCP gateway on its Cisco Unified Communications Manager
hosts systems.
Task 1: Register Endpoints
Activity

Step 1
On PC-1, open Google Chrome and navigate to Cisco Unified Communications Manager Administration
(https://10.1.5.5/ccmadmin). Log in using Administrator for the username and C0ll@B for the password.

Step 2
Select Device > Phone, click Find and observe if Cisco IP Communicator phones are displayed. If phones are
not displayed wait a while for the automation system to finish configuring Cisco Unified Communicacitons
Manager and then click Find again. Continue only when phones are displayed.

Step 3
On PC-1, start Cisco IP Communicator and configure it with the following settings:

Device Name: CIPC-1

TFTP Servers: 10.1.5.5

Cisco IP Communicator will reset due to the control protocol change from SCCP to SIP. Press OK
when the pop-up box appears.
Step 4
On PC-2, start Cisco IP Communicator and configure it with the following settings:

Device Name: CIPC-2

TFTP Servers: 10.1.5.5
Step 5
On PC-3, ping PSTN-GW with IP address 10.1.99.252. If ping is not successful wait for a while and try
again. Continue with next step only if ping success.

Step 6
On PC-3, start the Cisco IP Communicator phone simulator and configure it with the following settings:

Device Name: PSTN

TFTP Servers: 10.1.99.252
Task 2: Integrate a Cisco IOS MGCP Gateway with Cisco Unified Communications
Manager
MGCP gateway implementation includes configuration steps on both Cisco Unified Communications Manager (the
MGCP call agent) and the MGCP gateway that will be controlled. The steps to configure an MGCP gateway differ
depending on the type of MGCP gateway platform that is selected.

In this task, you will configure and verify MGCP registration.

Configure MGCP on Cisco Unified Communications Manager

The high-level Cisco Unified Communications Manager configuration steps for implementing an MGCP gateway
are as follows:
1. Add the MGCP gateway to Cisco Unified Communications Manager.
2. Configure the MGCP gateway in Cisco Unified Communications Manager.
3. Add one or more voice modules to the slots of the MGCP gateway in Cisco Unified Communications Manager.
4. Add VICs to the configured modules.
5. Configure the MGCP endpoints (one or more per VIC).

Now you will configure MGCP gateway on Cisco Unified Communications Manager.

Activity
Step 1
On PC-1, open Chrome or Firefox and navigate to https://10.1.5.5/ccmadmin. Log in using Administrator for
the username and C0ll@B for the password.

Step 2
Choose Device > Gateway, then click Find. Verify that no gateway has been configured yet.
Step 3
Click Add New then configure the MGCP gateway with the following parameters, click Save, and apply the
configuration:

Parameter Value

Gateway Type Cisco ISR 2901

Protocol MGCP

Domain name SJC-GW.cll-collab.internal

Description MGCP PRI GATEWAY

Cisco Unified Communications Manager Group HQ-CUCM-GROUP-1

Module in Slot 0 NM-4VWIC-MBRD

Global ISDN Switch Type NI2

Add MGCP Endpoints by Selecting Modules and VICs

Step 4
In the Configured Slots, VICs and Endpoints pane, from Subunit 1 in Slot 0, choose the module
VWIC2-2MFT-T1E1-T1 (Make sure that you select the correct module) and click Save.

The MGCP configuration depends on the Cisco IOS router hardware. You can use the show inventory
command on your router to display the hardware configuration of the router that is used. If your router
has different hardware, you must adapt the configuration accordingly.

Step 5
In the Configured Slots, VICs and Endpoints section of the gateway configuration, click the 0/1/0 port and
configure it with the following parameters:

You will be able to configure other gateway parameters only after you set the Device Protocol.

It is a best practice to enable the parameters Enable Status Poll, Display IE Delivery, and Redirecting
Number Enable Status Poll when you configure MGCP endpoints in Cisco Unified Communications
Manager.

The Enable Status Poll parameter enables the Cisco Unified Communications Manager advanced
service parameter, Change B-Channel Maintenance Status. The IE Delivery – Outbound parameter
enables delivery of the display information element in the SETUP message for the calling and
connected party name delivery service. The Redirecting Number IE Delivery – Outbound parameter
indicates the first redirecting number and the redirecting reason for the call when the call is forwarded.

Parameter Value
Parameter Value

Device Protocol Digital Access PRI

Device Pool SJC

Call Classification Off Net

Media Resource Group List HQ_MRGL

Location HQ

Enable status poll Enable

Calling Search Space GWY_HEADQUATERS_CSS

Display IE Delivery Enable

Redirecting Number IE Delivery - Outbound Enable

Step 6
In the Find and List Gateway page, click the checkbox next to SJC-GW.cll-collab.internal, click Apply Config to
Selected, then click Reset.

Step 7
Check the status of the MGCP gateway in Cisco Unified Communications Manager by listing all gateways
including their endpoints. Make sure that you select Show endpoints in the Find and List Gateway page.

The MGCP endpoint is shown with Status None. The reason is that you also have to enable MGCP at
the gateway.

Configure MGCP on a Cisco IOS Gateway

After you add the MGCP gateway in Cisco Unified Communications Manager Administration, you must configure
the Cisco IOS MGCP gateway to register to Cisco Unified Communications Manager. There are three methods of
configuring a Cisco IOS Software gateway to register to Cisco Unified Communications Manager via MGCP:
Use a configuration server to configure a Cisco IOS MGCP gateway:

Specify the IP address of the configuration server (the Cisco Unified Communications Manager TFTP
server) by using the ccm-manager config server command.
If more than one Cisco Unified Communications Manager TFTP server is deployed in the Cisco Unified
Communications Manager cluster, configure the gateway with all Cisco Unified Communications Manager
TFTP server IP addresses.
 Enable the configuration server feature by using the ccm-manager config command.

Manually configure a Cisco IOS MGCP gateway:

Specify the IP address of the MGCP call agent (the Cisco Unified Communications Manager server).
If more than one Cisco Unified Communications Manager server is used for call processing (that is, for
running the Cisco CallManager service), configure the gateway with a primary and a redundant call agent.
To do so, specify the IP addresses of two Cisco Unified Communications Manager call-processing servers.
Configure the global MGCP parameters. Examples of global MGCP configuration commands are the mgcp
packet and mgcp rtp commands.
Enable MGCP.

Use both a configuration server and manual configuration:

Use a configuration server to configure the MGCP gateway.

Disable the configuration server by using the ccm-manager config command.
Manually remove the configuration that is received from the configuration server, or add additional
configuration.

You will now you will use the configuration server feature so that the gateway is automatically configured with Cisco
Unified Communications Manager.

Step 8
Open Putty from the desktop, select Router 1 from the saved sessions, click Load, then click Open.

Step 9
Log in using Administrator for the username and C0ll@B for the password.

Step 10
Configure the MGCP gateway to be registered with Cisco Unified Communications Manager. Enter the following
commands:
 SJC-GW(config)# configure terminal
SJC-GW(config)# mgcp call-agent 10.1.5.5
SJC-GW(config)# ccm-manager config server 10.1.5.5
SJC-GW(config)# ccm-manager mgcp
SJC-GW(config)# mgcp
SJC-GW(config)# ccm-manager config

Verify MGCP Configuration

You will verify MGCP gateway integration with Cisco Unified Communications Manager after troubleshooting.

Step 11
Check the status of the MGCP gateway in Cisco Unified Communications Manager by listing all gateways
including their endpoints. Make sure that you select Show endpoints on the Find and List Gateway page.

You will see the status Registered with CUCM-PUB.CLL-COLLAB.INTERNAL and the IP address of the MGCP
gateway 10.1.5.252.

The MGCP configuration server feature does not support fractional PRIs. Therefore, you must manually
change the time slot range of the router if you do not want to have a full PRI. In this lab, you will use the
full time slot range.

Step 12
On the SJC-GW router, verify the MGCP gateway registration status by using the show mgcp command.

SJC-GW# show mgcp

MGCP Admin State ACTIVE, Oper State ACTIVE - Cause Code NONE
MGCP call-agent: 10.1.5.5 Initial protocol service is MGCP 0.1
MGCP validate call-agent source-ipaddr DISABLED
MGCP validate domain name DISABLED
MGCP block-newcalls DISABLED
MGCP send SGCP RSIP: forced/restart/graceful/disconnected DISABLED
MGCP quarantine mode discard/step
MGCP quarantine of persistent events is ENABLED
MGCP dtmf-relay for VoIP is SDP controlled
MGCP dtmf-relay for voAAL2 is SDP controlled
MGCP voip modem passthrough mode: NSE, codec: g711ulaw, redundancy: DISABLED,
MGCP voaal2 modem passthrough disabled
MGCP voip modem relay: Disabled
MGCP voip mdste modem relay: Disabled
MGCP voip mdste modem mer relay: Disabled
MGCP T.38 Named Signalling Event (NSE) response timer: 200
MGCP Network (IP/AAL2) Continuity Test timer: 200
MGCP 'RTP stream loss' timer disabled
MGCP request timeout 500
MGCP maximum exponential request timeout 4000
MGCP rtp unreachable timeout 1000 action notify
MGCP gateway port: 2427, MGCP maximum waiting delay 3000

You will see that the MGCP gateway has been successfully integrated with Cisco Unified Communications
Manager.

Task 3: Implement Inbound and Outbound PSTN Calling

You will implement inbound and outbound PSTN calling by creating a complete dial plan with call routing and digit
manipulation features in Cisco Unified Communications Manager.

Activity
Configure Digit Manipulation

There are many digit-manipulation tools in Cisco Unified Communications Manager that allow you to implement
flexible and transparent dial plans:
External phone number masks: The external phone number mask instructs the call-routing component to use
the external (PSTN) phone number of a calling IP phone, rather than its internal DN, for the caller ID
information. The external phone number mask is set on a line-by-line basis on the Directory Number
Configuration page of a device. The use of the external phone number mask is enabled globally per PSTN route
pattern.

The external phone number mask configuration can be applied to many different call-routing components and
functions:
Route pattern
Translation pattern
Calling-party transformation pattern
Hunt pilot
Route-group manipulation settings within a route list
Automatic alternate routing

Translation pattern: Cisco Unified Communications Manager uses translation patterns to manipulate dialed
digits before routing a call or to manipulate the calling-party number. Sometimes, the dialed number is not the
number that the system uses. In other cases, the dialed number is not a number that the PSTN recognizes. The
translation pattern can also be used to block certain patterns.
Configuration of a translation pattern is like configuration of a route pattern. Each pattern has calling- and
called-party transformations settings. The difference is that when Cisco Unified Communications Manager
applies the translation pattern, it restarts the digit analysis process to perform another call-routing process for
the modified number.

Digit stripping: A Discard Digit Instruction (DDI) removes part of the dialed digit string; for example, when an
access code is needed to route the call to the PSTN but the PSTN switch does not expect that access code.
The DDI then passes the number on to the adjacent system.
Digit stripping is configured under the called-party transformations, by selecting a DDI. Digit stripping can be
configured in route patterns and in route groups of a route list.

For the PreDot DDI to work, the route pattern must include a dot (.). The dot is not dialed; Cisco Unified
Communications Manager uses the dot to determine how many digits to strip (all digits before the dot).
Implement Digit Manipulation of the Calling and Called Numbers on Outbound PSTN Calls
You will perform digit manipulation of the calling and called numbers on outbound PSTN calls to translate calling
number 11XXX to 4085551XXX.

Step 1
In Cisco Unified Communications Manager Administration, select Device > Phone, click Find, then click CIPC-1.

Step 2
Click Line [1] – 11001 in LINE_INTERNAL_PT.

Step 3
In the Directory Number Configuration page, configure the External Phone Number Mask with the expression
4085551XXX on the first line of the phone.

Later in this task, you will enable the Use Calling Party’s External Phone Number Mask parameter in the
Route Pattern configuration to use the configured External Phone Number Mask.

To discard the 9 access code from the called number when you place calls to the PSTN, you will use the
discard digits PreDot parameter in the Route Patten configuration.
Implement Digit Manipulation of the Called Number on Inbound PSTN Calls
You will configure a translation pattern to translate the called number from the PSTN to the internal number of your
CIPC-1 phone.

Step 4
From Cisco Unified Communications Manager Administration, choose Call Routing > Translation Pattern and
click Add New. Configure a translation pattern with the following parameters and click Save.

The Provide Outside Dial Tone parameter makes Cisco Unified Communications Manager play a
secondary dial tone.

Parameter Value

Translation Pattern 4085551001

Partition GWY_HEADQUARTERS_PT

Description 4085551001 DID to 11001

Calling Search Space LINE_INTERNAL_ONLY_CSS

Provide Outside Dial Tone Disable

Use Calling Party’s External Phone Number Mask Enable

Called Party Transform Mask 11001

Create the Dial Plan on Cisco Unified Communications Manager
You will configure a dial plan with a route group, a route list, and route patterns to route calls to local, national,
international, and emergency PSTN destinations from the San Jose location and verify its operation.

Step 5
Select Call Routing > Route/Hunt > Route Group. Configure a route group with the following parameters and
click Save:

Route Group Name: SJC ROUTE GROUP

Selected Devices: S0/SU1/DS1-0@SJC-GW.cll-collab.internal

Step 6
In Cisco Unified Communications Manager Administration, choose Call Routing > Route/Hunt > Route List.
Configure a route list with the following parameters and click Add New:

Route List Name: SJC ROUTE LIST

Description: San Jose Route List
Cisco Unified Communications Manager Group: HQ-CUCM-GROUP-1
Step 7
In the Route List Member Information section, click the Add Route Group button and associate Route Group
SJC ROUTE GROUP with the Route List SJC ROUTE LIST. Click Save and Reset Route List.

Step 8
Click Save, then click Save again.

Step 9
In Cisco Unified Communications Manager Administration, choose Call Routing > Route/Hunt > Route
Pattern. Click Add New and configure the new route pattern to route local calls with the following parameters
and click Save:
Parameter Value

Route Pattern 9.[2-9]XX[2-9]XXXXXX

Route Partition DEVICE_HEADQUATERS_PT

Description Local Calls Route Pattern

Gateway/Route List SJC ROUTE LIST

Call Classification OffNet (Leave default)

Use Calling Party’s External Phone Number Mask Enable

Discard Digits PreDot

All other fields Leave default

Step 10
Configure another new route pattern to route national calls with the following parameters and click Save.

You can simplify creation of route patterns by using the Copy button in the created route patterns.

Parameter Value

Route Pattern 9.1[2-9]XX[2-9]XXXXXX

Route Partition DEVICE_HEADQUATERS_PT

Description National Calls Route Pattern

Gateway/Route List SJC ROUTE LIST

 Parameter Value

Call Classification OffNet (Leave default)

Use Calling Party’s External Phone Number Mask Enable

Discard Digits PreDot

All other fields Leave default

Step 11
Add another route pattern to route international calls with the following parameters and click Save:

Parameter Value

Route Pattern 9.011!

Route Partition DEVICE_HEADQUATERS_PT

Description International Calls Route Pattern

Gateway/Route List SJC ROUTE LIST

Call Classification OffNet (Leave default)

Use Calling Party’s External Phone Number Mask Enable

Discard Digits PreDot

All other fields Leave default

Step 12
In the Find and List Route Pattern section, configure a route pattern to route international calls with the following
parameters and click Save:

Parameter Value

Route Pattern 9.011!#

Route Partition DEVICE_HEADQUATERS_PT

Description International Calls Route Pattern

Gateway/Route List SJC ROUTE LIST

Call Classification OffNet (Leave default)

Use Calling Party’s External Phone Number Mask Enable

Discard Digits PreDot

All other fields Leave default

Step 13
Add another route pattern to route emergency calls with the following parameters and click Save:

If the dial plan contains overlapping route patterns, Cisco Unified Communications Manager does not
route the call until the interdigit timer expires (even if dialing a sequence of digits to choose a current
match is possible). You must check the Urgent Priority check box to interrupt interdigit timing when
Cisco Unified Communications Manager must route a call immediately.

Parameter Value

Route Pattern 911

Route Partition DEVICE_HEADQUATERS_PT

Description Emergency Calls Route Pattern

Gateway/Route List SJC ROUTE LIST

Call Classification OffNet (Leave default)

Urgent Priority Enable

Use Calling Party’s External Phone Number Mask Enable

All other fields Leave default

Step 14
Add another route pattern to route emergency calls with the following parameters and click Save:

Parameter Value

Route Pattern 9.911

Route Partition DEVICE_HEADQUATERS_PT

Description Emergency Calls Route Pattern

Gateway/Route List SJC ROUTE LIST

Call Classification OffNet (Leave default)

Urgent Priority Enable

Use Calling Party’s External Phone Number Mask Enable

Discard Digits PreDot

All other fields Leave default

Step 15
Place a call from CIPC-1 to the local PSTN number 94085551234 and observe the status of the call on the
PSTN emulator.

The call works. Why?

You configured the route pattern 9.[2-9]XX[2-9]XXXXXX, which matches the local number 94085551234. The
route pattern points to the route list named SJC ROUTE LIST. The route list SJC ROUTE LIST includes the route
group SJC ROUTE GROUP. The SJC ROUTE GROUP is configured with only one member, S0/SU1
/DS1-0@SJC-GW.cll-collab.internal, which is the MGCP gateway that was configured in the previous task.
Therefore, your call works.

You configured an external phone number mask in the Directory Number Configuration of the DN 11001 and
enabled the Use Calling Party’s External Phone Number Mask in Route Pattern parameter. Therefore, your
calling number was changed before it was sent to the PSTN from 11001 to 4085551001.

Step 16
 Place a call from CIPC-1 to the national PSTN number 919195551234 and observe the status of the call on the
PSTN emulator.

The call works. Why?

You configured the Route Pattern 9.1[2-9]XX[2-9]XXXXXX, which matches the national number 919195551234.
The route pattern points to the route list named SJC ROUTE LIST. The route list SJC ROUTE LIST includes the
route group SJC ROUTE GROUP. The SJC ROUTE GROUP is configured with only one member, S0/SU1
/DS1-0@SJC-GW.cll-collab.internal, which is the MGCP gateway that was configured in the previous task.
Therefore, your call works.

Step 17
Place a call from CIPC-1 to the international PSTN number 9011442079460132 and observe the status of the
call on the PSTN emulator.

The call works. Why?

You configured route pattern 9.011!, which matches the international number 9011442079460132. The route
pattern points to the route list named SJC ROUTE LIST. The route list SJC ROUTE LIST includes the route
group SJC ROUTE GROUP. The SJC ROUTE GROUP is configured with only one member, S0/SU1
/DS1-0@SJC-GW.cll-collab.internal, which is the MGCP gateway that was configured in the previous task.
Therefore, your call works.

Step 18
Place a call from CIPC-1 to the emergency PSTN number 9911 and observe status of the call on the PSTN
emulator.

The call works. Why?

You configured route pattern 9.911, which matches the emergency number 9911. The route pattern points to the
route list named SJC ROUTE LIST. The route list SJC ROUTE LIST includes the route group SJC ROUTE
GROUP. The SJC ROUTE GROUP is configured with only one member, S0/SU1/DS1-0@SJC-GW.cll-
 collab.internal, which is the MGCP gateway that was configured in the previous task. Therefore, your call
works.

Step 19
Place a call from the SJC-Local line on the PSTN simulator to 14085551001.

The call works. Why?

The translation pattern that you configured in this task translated the called number that came from the PSTN to
the SJC-GW router from 4085551001 to 11001. Therefore, the call works.