Table of Contents

Primary Call Control Components
Primary Call Control Interfaces
Understanding MGCP
Configuration Tasks for MGCP

Configuring MGCP IP Addresses
Configuring MGCP Core Settings

Understanding Sessions
Configuration Tasks for Sessions

Configuring Session Sets

Viewing Session Set Information
Adding a Session Set

Configuring Session Groups

Viewing Session Group Information
Adding a Session Group

Configuring Session Managers

Viewing Session Manager Information
Adding a Session Manager

Understanding ISDN D Channels Usage
Configuration Tasks for D Channels

Adding a MACSAP Profile
Adding a DLSAP Profile
Adding D-Channels
Viewing LAPD Parameters

Configuring MGC Interfaces

The Cisco MGX 8260 Media Gateway works in conjunction with a Cisco Media Gateway Controller (MGC) and the Public Switched Telephone Network (PSTN) to control voice and data calls.

Primary Call Control Components

The following are the primary components of the call control system:

• Signal Transfer Point (STP)

STPs are components in the Signaling System 7 (SS7) network that route management traffic between Service Switching Points (SSPs) and Service Control Points (SCPs).

• Central Office (CO)

The CO provides telephone services to subscribers and handles the associated management traffic. The CO is often an SSP in the SS7 network.

• Cisco Media Gateway Controller (MGC)

A MGC, such as the Cisco VSC3000 MCG, communicates with the SS7 network and Cisco MGX 8260 Media Gateways to process multimedia calls. These communication links use backhaul channels to adapt PSTN signaling to IP/ATM signaling.

• Cisco Media Gateway

The Cisco MGX 8260 Media Gateway switches voice and data traffic between PSTN circuits and a packet backbone, and it works with PSTN signaling points for voice call control and with Cisco MGCs for multimedia call control. In addition, the Cisco MGX 8260 Media Gateway adapts PSTN signaling to IP/ATM signaling so the Cisco MGC can control PSTN calls directly.

Primary Call Control Interfaces

The Cisco MGX 8260 Media Gateway communicates with other media and signaling equipment through the following interfaces:

• Integrated Services Digital Network

The Cisco MGX 8260 Media Gateway communicates with PSTN equipment using an Integrated Services Digital Network (ISDN) D-Channel of a DS1 trunk. Within the D channel, multiple digital links may exist, which are defined by DLSAP and MACSAP profiles.

• MGCP

The Cisco MGX 8260 Media Gateway exchanges switching information with Cisco MGCs using Media Gateway Control Protocol (MGCP) over an IP network. The physical interface is the Management Port on the SCC back card.

• Backhaul

The Cisco MGX 8260 Media Gateway adapts PSTN signaling to IP/ATM signaling using backhaul channels, which are organized into sets and groups for reliability. These channels provide the mechanism by which an Cisco MGC implements PSTN signaling and manages multimedia calls. The physical interface is the Management Port on the SCC back card.

Understanding MGCP

This section describes how to configure and view MGCP. The Cisco MGX 8260 Media Gateway implements the standard MGCP protocol stack (see Figure 9-1).

The protocol stack contains the following layers:

• MGCP

• UDP (User Datagram Protocol)

• IP (Internet Protocol)

• Physical---Ethernet LAN

The Cisco MGX 8260 Media Gateway Release 1.2 and greater implement the K-parameter feature, which improves message delivery through UDP.

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Note The Cisco MGX 8260 is the only Cisco gateway product that implements the K-parameter.

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The following diagram shows how to configure MGCP IP addresses in a fully redundant system (see Figure 9-2).

Configuration Tasks for MGCP

To configure MGCP, perform the following tasks:

• Set IP addresses and ports

• Configure MGCP core settings

The procedures in this section explain how to configure all MGCP options, and include a sample configuration that supports the Cisco SS7 PRI Gateway Solution. The sample configuration demonstrates a fully redundant solution with two subnetworks and two Cisco MGCs.

Configuring MGCP IP Addresses

Before beginning this procedure, obtain the IP addresses and ports for your MGCP interface. Make sure that your IP and port selections do not conflict with other equipment on the networks.

To configure MGCP IP addresses, follow these steps:

Step 2 Click MGCP.

Step 3 Click Default.

The MGCP Default Setting screen opens:

Step 4 Specify the MGCP parameters:

Parameter	Description	Example
Primary MGCP Address 1	The default domain name or IP address of the primary Cisco MGC for Network 1. Use the standard dot notation for IP addresses.	10.15.26.1
Primary MGCP UDP Port 1	The default UDP port of the primary Cisco MGC for Network 1.	2427
Primary MGCP Address 2	The default domain name or IP address of the primary Cisco MGC for Network 2. Use the standard dot notation for IP addresses.	10.15.27.1
Primary MGCP UDP Port 2	The default UDP port of the primary Cisco MGC for Network 2.	2427
Secondary MGCP Address 1	The default domain name or IP address of the secondary Cisco MGC for Network 1. Use the standard dot notation for IP addresses.	10.15.26.2
Secondary MGCP UDP Port 1	The default UDP port of the secondary Cisco MGC for Network 1.	2427
Secondary MGCP Address 2	The default domain name or IP address of the secondary Cisco MGC for Network 2. Use the standard dot notation for IP addresses.	10.15.27.2
Secondary MGCP UDP Port 2	The default UDP port of the secondary Cisco MGC for Network 2.	2427
Connection Status	The current status of the MGCP connection, as follows: unknown---Undefined status connected---Message is sent and response to it is received connecting---Message is sent and waiting for response noSuchName---No domain name/IP address is found noResponse---Timeout on message	read-only
Time Stamp	The time stamp.	read-only
Con. Status Time Stamp	The time the connection status last changed.	read-only
Local Address 1	The domain name or IP address of the Cisco Media Gateway interface for Network 1. This address needs to be on the same subnet as the primary MGCP Address. Specify the IP address in standard dot notation.	10.15.26.20
Local Primary Port 1	The primary UDP port of the Cisco Media Gateway interface for Network 1.	2427
Local Address 2	The domain name or IP address of the Cisco Media Gateway interface for Network 2. This address needs to be on the same subnet as the secondary MGCP address. Specify the IP address in standard dot notation.	10.15.27.20
Local Primary Port 2	The primary UDP port of the Cisco Media Gateway interface for Network 2.	2427

Step 5 Click Modify.

The system configures the MGCP IP addresses.

Configuring MGCP Core Settings

MGCP core settings enable and disable the protocol and control how it works.

To configure MGCP IP addresses, follow these steps:

Step 2 Click MGCP.

Step 3 Click Core.

The MGCP Core Setting screen opens:

Step 4 Specify the MGCP core parameters:

Parameter	Description	Example
Messages Bad Version	The total number of incoming messages delivered to the protocol entity that were for an unsupported protocol version.	read-only
Request Retries	The maximum number of retries for a request that times out.	12
Restart InProg MWD	The maximum waiting delay, in milliseconds, before the Cisco Media Gateway interface sends the Restart In Progress message to the Cisco MGC.	4000
Restart Delay	The delay for the restart process. Use -1 to specify an infinite delay.	-1
Request TimeOut	The time in milliseconds before retransmitting an unacknowledged message.	5000
UnRecognized Packets	The number of unrecognized packets.	read-only
(Set) Operational Status	The administrative state, as follows: up---MGCP is up and running bringUpInProgress---MGCP is coming up shutDownInProgress---MGCP is shutting down down---MGCP is administratively down	read-only
Capabilities Package Name	A list of the capabilities packages: Generic Media Package DTMF package MF Package Trunk Package Line Package Handset Package RTP Package Network Access Server Package Announcement Server Package Script Package	read-only

Step 5 Click Set Operational Status.

Step 6 Select Up for the Admin. Status Setting.

Step 7 Click Set New Status to change the value and return to the MGCP Core Setting screen.

Step 8 Click Modify. The system configures the MGCP core settings.

Understanding Sessions

The Session Manager organizes individual sessions into groups and sets (see Figure 9-3).

When adding sessions, create a structure that supports reliable operation. The goal for a fully redundant system is to provide multiple management sessions to multiple Cisco MGCs by using multiple physical networks (see Figure 9-4).

Configuration Tasks for Sessions

To configure MGCP, you perform the following tasks:

• Add session sets

• Add session groups

• Add session managers

The procedures in this section explain how to configure all session options and include a sample configuration that supports the Cisco SS7 PRI Gateway Solution. The sample configuration initializes four session managers, including primary and secondary subnet connections to both Cisco MGCs.

Configuring Session Sets

You can view and add session sets.

Viewing Session Set Information

To view session set information, follow these steps:

Step 2 Click Set.

The Session Set screen opens:

Step 3 Interpret the session set information as follows:

Displayed Information	Description
Index	The session set index number.
State	The state of the session set: idle outOfService standby active full switchOver
Total Groups	The total number of groups added to this session set.
Min Slot	The minimum slot number for this session set.
Min Line	The minimum line number for this session set.
Max Slot	The maximum slot number for this session set.
Max Line	The maximum line number for this session set.
Redun Mode	The current redundancy mode: nonFaultTolerant faultTolerent
Active Group	The group number that is in the active state. Displays -1 if no group is active.
Switch Failed	The total number of switchover failures.
Switch Succeeded	The total number of switchover successes.
Down Count	The number of times the session set went down.

Adding a Session Set

To add a session set, follow these steps:

Step 2 Click Set.

The Session Set screen opens.

Step 3 Click the + icon.

TheAdd Session Set form opens:

Step 4 Configure the session set parameters.

Parameter	Description	Example
Set Index	An index number for the new set.	1
Redundant Mode	The redundancy mode: nonFaultTolerant faultTolerant	nonFault Tolerant
Minimum Slot Number	The minimum Cisco MGX 8260 slot number for this Session Set. Valid entries are 1-8 and 11-16.	13
Maximum Slot Number	The maximum Cisco MGX 8260 slot number for this Session Set. Valid entries are 1-8 and 11-16.	13
Minimum Line Number	The minimum line number for this Session Set. Valid entries are: BSC: 1-168 NSC: 1-16	1
Maximum Line Number	The maximum line number for this Session Set. Valid entries are: BSC: 1-168 NSC: 1-16	168

Step 5 Click Add.

Configuring Session Groups

You can view and add session groups.

Viewing Session Group Information

To view session set status, follow these steps:

Step 2 Click Group.

The Session Group screen opens:

Step 3 Interpret the session group information as follows:

Displayed Information	Description
Set Index	The set number to which this group belongs
Gr. Index	The group index number
Gr. State	The state of the session group: outOfService inService
Use State	The use state of the session group: none standby active
Act. Sess	The active session number of the group. Displays -1 if no session is active.
Prev Sess	The previously active session Set Index of the group.
Total Sess	The total number of sessions for the group.
Total Act Sess	The total number of active sessions in the group
Sess Fail	The total number of session failures for the group.
Fail Over Success	The total number of failover successes for this group.
Active Pkts Rcvd	The total number of packets received for this group.
Standby Pkts Rcvd	The total number of packets sent by this group.
PDU Post Err	The total number of active packets received for this group.

Adding a Session Group

To add a session group, follow these steps:

Step 2 Click Group.

The Session Group screen opens.

Step 3 Click the + icon.

The Add Session Group form opens:

Step 4 Configure the session group parameters.

Parameter	Description	Example
Set Index	The index number of the set to which this group belongs	1
Group Index	A group number for the new group	1

Step 5 Click Add.

The system adds the session group.

Configuring Session Managers

You can view and add session managers.

Viewing Session Manager Information

To view session manager information, follow these steps:

Step 2 Click Manager.

The Session Manager screen opens:

Step 3 Interpret the Session Manager information as follows:

Displayed Information	Description
Set Index	The session set to which the group containing the session manager belongs
Group Index	The session group of which the session manager is a member
Sess. Index	The session manager number
Priority	The session manager connection priority
State	The session manager state: open openWait openXfer close closeWait userClose autoReset
InUse State	The use state of the session manager: outOfService inService blocked
Local Port	The local UDP Port
Local Addr	The local IP address of the connection
Remote Port	The remote UDP port
Remote Addr	The remote IP address of the connection

Adding a Session Manager

To add a Session Manager connection, follow these steps:

Step 2 Click Manager.

The Session Manager screen opens.

Step 3 Click the + icon.

The Add Session Manager form opens:

Step 4 Configure the parameters for the session connection.

Parameter	Description	Example
Priority	The Session Manager connection priority.	1
Local Port	The local port for the session.	Table 9-1
Local Address	The local IP address for the session.	Table 9-1
Remote Port	The remote port for the session.	Table 9-1
Remote Address	The remote IP address for the session. The remote address must be on the same subnet as the local address.	Table 9-1

Step 5 Click Add.

The system adds the Session Manager.

Table 9-1: Session Manager Example Configuration

Manager	Local Port	Local Addr.	Remote Port	Remote Addr.	Usage
1	7007	10.15.26.20	7007	10.15.26.1	Primary Cisco MGC on subnet 1
2	7007	10.15.27.20	7007	10.15.27.1	Primary Cisco MGC on subnet 2
3	7008	10.15.26.20	7007	10.15.26.2	Secondary Cisco MGC on subnet 1
4	7008	10.15.27.20	7007	10.15.27.2	Secondary Cisco MGC on subnet 2

Understanding ISDN D Channels Usage

The Cisco MGX 8260 Media Gateway extends D channel signaling to an MGC via a backhaul channel (see Figure 9-5).

The DLSAP and MACSAP profiles define the following interfaces of the ISDN protocol stack (see Figure 9-6).

Configuration Tasks for D Channels

The following section describes the high-level procedure for configuring a D channel on an existing DS3 trunk:

Step 2 Define a MACSAP profile.

Step 3 Define a D-Channel on a PRI ISDN line within the DS3 trunk, using the profiles you defined in Step 1 and Step 2.

The procedures in this section explain how to configure all D channel options, and include a sample configuration that supports the Cisco SS7 PRI Gateway Solution. The sample configuration initializes four session managers, including primary and secondary subnet connections to both Cisco MGCs.

The procedures in this section explain how to configure all D channel options and include a sample configuration that supports the Cisco SS7 PRI Gateway Solution. The sample configuration initializes 79 D channels, 23 redundant and 56 nonredundant. These D channels use DS1 lines that are subchannels of the DS3 lines.

Adding a MACSAP Profile

MACSAP management consists of adding and deleting profiles. You need at least one profile to add D channels.

To add a MACSAP profile, follow these steps:

Step 2 Click ISDN.

Step 3 Click Macsap Profile.

The Macsap Profile screen opens:

Step 4 Click the + icon.

The Add Macsap Profile form opens:

Step 5 Specify the Macsap profile parameters.

Parameter	Description	Example
Profile Index	A numeric identifier for the profile.	1
Interface	The type of profile.	Network
Link Arbitration	The link setup arbitration scheme: passive or active.	Passive
LAPD Type	The LAPD interface type.	ccitt
Max Outstanding Frames	The maximum number of sequentially numbered I-frames that may be outstanding.	7
Timer Q Up Threshold	The upper threshold for I-frame queue. When the I-frame queue size exceeds this threshold, the congestion timer is started and flow-control is turned on.	1000
Timer Q Low Threshold	The lower threshold for I-frame queue. When the I-frame queue size falls below this threshold, the congestion timer is stopped and flow-control is turned off.	100
Connection Timer	The connection timer.	500
t201 Timer	The minimum time between transmissions of Terminal Endpoint Identifier (TEI) identity check messages.	20
t202 Timer	The minimum time between transmissions of TEI identity check messages.	2
TEI Check Timer	The TEI check timer. The value 1025 that means the TEI Check Timer is disabled.	100
N202	The minimum time between transmissions of TEI Identity check messages.	3
Lowest Auto TEI	The allocated TEI value. When configured for Automatic TEI Assignment, ASP can allocate TEIs greater than or equal to Lowest Automatic TEI.	1
Keep L1 Up	The state of the Keep MAC Up All The Time flag.	true

Step 6 Click Add. The system adds the profile and updates the Macsap Profile screen.

Note If you add an incorrect profile, delete the profile using the - icon and start over.

Adding a DLSAP Profile

DLSAP management consists of adding and deleting profiles. Define at least one profile before adding D channels.

To add a DLSAP profile, follow these steps:

Step 2 Click ISDN.

Step 3 Click Dlsap Profile.

The Dlsap Profile screen opens:

Step 4 Click the + icon.

The Add Dlsap Profile form opens:

Step 5 Specify the Dlsap profile parameters.

Parameter	Description	Parameter
Profile Index	A numeric identifier for the profile.	1
Frame Length	The frame length, which is the maximum number of octets in an information field.	1960
Window Size	The maximum number of sequentially numbered I-frames that may be outstanding. The window size depends on the modulus. If the modulus is 8, then the window size is (1-8) and if the modulo is 128, the window size is (1-128).	7
Retrans. Count	The maximum number of retransmissions of a frame.	3
Congestion Timer	The number of seconds after which DLCs are dropped during periods of network congestion.	200
t200 Timer	The number of seconds before frame transmission may be initiated.	1
t203 Timer	The maximum time allowed without frames being exchanged, in seconds.	10
Modulus	Each I-frame is sequentially numbered and may have values 0 through (N-1) where N is this modulus.	128
TEI Assign	The TEI assignment setting: automatic---TEI is selected by the ASP Layer Management procedure on the network side. Default: 2, which yields a TEI of 1. nonAutomatic---TEI is selected by the user	automatic
Max DLCs	The maximum number of DLCs for this DLSAP.	1
Starting TEIs	The starting number for reassigning TEIs. This number is used in conjunction with the previous two parameters to number TEIs. For example, assume that TEI Assignment is nonAutomatic, maximum DLCs for this DLSAP is 4, and TEI is 14. When a D channel is added, four TEIs starting at 14-1 are preconfigured.	2

Step 6 Click Add.

The system adds the profile and updates the Dlsap Profile screen.

Note If you add an incorrect profile, delete the profile using the - icon and start over.

Adding D-Channels

The Cisco MGX 8260 Media Gateway communicates with PSTN equipment over Primary Rate Interface (PRI) ISDN D channels.

Adding a D channel requires an existing DS3 line and suitable DLSAP and MACSAP profiles.

To add a D channel, follow these steps:

Step 2 Click ISDN.

Step 3 Click DChan Config.

The DChan Config screen opens:

Step 4 Click the + icon.

The Add Dlsap Profile form opens:

Step 5 Specify the D channel parameters.

Parameter	Description	Example
Slot	The slot number for this D channel	See Table 9-1
Line	The line number for this D channel.	See Table 9-1
Dlsap Profile Number	The number of the profile that defines the Dlsap settings.	1
Dlsap Index	The instance number of a Dlsap profile. The profile defines a template for the configuration; the Dlsap index is created from the template.	1
Macsap Profile Number	The number of the profile that defines the MacSap settings.	1
Macsap Index	The instance number of a Macsap profile. The profile defines a template for the configuration; the Macsap index is created from the template.	1

Step 6 Click Add. The system adds the profile and updates the DChan Config screen.

Step 7 Repeat Step 4 and Step 5 for each D channel. Refer to the following table:

Table 9-1 D-Channel Sample Configuration

Slot	Line
11	8 through 11 and 85 through 113 and 127
13	5 through 28
15	1 through 29 and 36

These D channels use the DS1 lines configured beforehand. For more information, see the "Adding DS1 Lines" section.

Note If you add an incorrect channel, delete it using the - icon and start over.

Viewing LAPD Parameters

You don't need to configure LAPD, but you can view its status.

To view LAPD status, follow these steps:

Step 2 Click Session.

Step 3 Click LAPD.

The LAPD Card Table screen opens:

Step 4 View the LAPD summary.

Displayed Information	Description
Card Index	The physical card number
Number of Phy. Links	The total number of physical links for this instance of LAPD on the card
Num of DLCs	The total number of DLCs for this instance of LAPD on the card
Num of LAPD Links	The total number of LAPD links for this instance of LAPD on the card
Num of ASPs	The number of Assigned Source Points

Posted: Tue Jun 20 20:41:54 PDT 2000
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