VG248 Software Configuration Guide v1.2
Overview
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Overview

Table Of Contents

Overview

Using the VG248 with Analog Devices

Supported Analog Telephony Features

Supported Telephony Features

Understanding Voice-Mail Message Indicators

Understanding Call Control Modes

Understanding Caller ID Support

Supported Analog Devices

Analog Phones

Speakerphones

Private Line Automatic Ringdown Phones

Fax Machines

Modems

Using the VG248 with Voice Mail Systems

Choosing a Configuration Option

Basic Configuration

Chained Configuration

Multiplexing Configuration

Supported Protocols

Data and Voice Protocols

Voice Mail Protocols

Network Management Protocols

Understanding SNMP Support

Understanding Trap Support

Understanding Supported MIBs


Overview


The Cisco VG248 Analog Phone Gateway (VG248) enables you to integrate analog telephones, modems, and fax machines with the Cisco CallManager IP telephony system. You can also integrate Cisco CallManager with analog voice mail systems that implement any of the following voice mail protocols:

Simplified Message Desk Interface (SMDI)

NEC Message Center Interface protocol (MCI)

Ericsson Voice Mail Protocol

The following topics provide an overview of the supported analog devices, voice mail systems, and the supported data and voice protocols:

Using the VG248 with Analog Devices

Using the VG248 with Voice Mail Systems

Supported Protocols

Using the VG248 with Analog Devices

The Cisco VG248 is a high-density gateway for using analog phones, fax machines, modems, and speakerphones within the Cisco IP telephony network (see Figure 1-1). The Cisco VG248 offers 48 fully-featured analog phone lines to be used as extensions to the Cisco CallManager system in a compact 19-inch rack-mount chassis.

Figure 1-1 VG248 Integrated in the Cisco IP Telephony Network

These sections provide detailed information about the analog telephony features and devices supported by the VG248:

Supported Analog Telephony Features

Supported Analog Devices

Supported Analog Telephony Features

Review the following sections to understand which telephony features are supported by the VG248 and to understand how they are implemented:

Supported Telephony Features

Understanding Voice-Mail Message Indicators

Understanding Call Control Modes

Understanding Caller ID Support

Supported Telephony Features

The VG248 supports the following features:

Call Transfer (supervised and blind)

Conference

Call Waiting (with calling party ID display)

Hold (including switch between parties on hold)

Call Forward All

Send All Calls to Voice Mail

Pickup

Group Pickup

Call Voice Mail

Speed Dial (maximum of 9 speed dials)

Last Number Redial

Caller ID

To understand how users access and use these features, see Table 1-1.

Understanding Voice-Mail Message Indicators

The VG248 can receive message-waiting indicator (MWI) information from Cisco CallManager and send it to analog phones. The VG248 sends MWI messages using any of the following methods:

Playing stutter dial tone when a user picks up the phone

Illuminating the MWI lamp on the phone

Using caller ID mechanism to send information to the LCD screen on the phone

You can enable or disable any of these options. See the "Choosing Message Waiting Indicator Type" section for details.

Understanding Call Control Modes

The VG248 supports different call control modes, which indicate how users access and use the supported telephony features. You can choose the call control mode appropriate to the specific needs of your users and the abilities of your analog devices. The supported call control modes include:

Standard

Feature

Basic

Restricted

To understand the differences among these modes, keep the following tips in mind:

The four modes differ in how they support call waiting, transfer, and other phone features.

Users can access features using the hook flash, 0-9, *, or # buttons, depending on how you have configured the feature codes.

You cannot use a double flash hook.

See the "Assigning Feature Codes" section for details about setting the call control mode on the VG248.

Standard

Standard is the default telephony mode, and it provides standard Bellcore features, such as used in North America.

Users use the flash button or hook flash to transfer, conference and hold calls, with the following requirements:

You cannot use hook flash to activate phone features.

When putting calls on hold, the first call can be either incoming or outgoing.

When transferring a call or establishing conferences, the second call must be outgoing.

Users also use feature codes to activate other features in standard mode. See Table 1-1 for details about how to access the telephony features in standard mode.

Feature

For simple calls, the feature mode is indistinguishable from the standard mode. While on calls, users use the flash button or hook flash to get a second dial tone to dial a second party. However, users then must enter feature codes to transfer the call or establish a conference.

When using feature mode with two calls established, the hook flash cycles around four states:

1. First call connected

2. Feature code tone

3. Second call connected

4. Feature code tone

These different states enable you to keep both calls active and switch between them. Thus, unlike Standard mode you can keep both calls active for as long as you want and freely switch between them.

To transfer or conference, you need to enter the relevant feature code at one of the feature tones (which are similar to dial tones except you can only enter feature codes rather than being able to dial a directory number).

See Table 1-1 for details about how to access the telephony features in feature mode.

Basic

This mode provides a simple phone interface but does not provide call transfer or conference features. Basic mode might work best for fax machines or modems. See Table 1-1 for details about how to access the telephony features in basic mode.

Restricted

This is the most limited of the available call modes. Restricted mode is most appropriate for situations in which a billing system is used that begins charging when calls connect. Therefore, call waiting and other features requiring hook flash are not supported. See Table 1-1 for details about how to access the telephony features in restricted mode.

Table 1-1 Overview of Default Feature Access in Call Control Modes 

Restricted
Basic
Standard
Feature
SpeedDial
SpeedDial
SpeedDial
SpeedDial

*1

*2

*1

*2

*1

*2

*1

*2

*3

*4

*3

*4

*3

*4

*3

*4

*5

*6

*5

*6

*5

*6

*5

*6

*7

*8

*7

*8

*7

*8

*7

*8

*9

 

*9

 

*9

 

*9

 
Last Number Redial
Last Number Redial
Last Number Redial
Last Number Redial

*#

*#

*#

*#

Pickup
Pickup
Pickup
Pickup

**3

**3

**3

**3

Group Pickup
Group Pickup
Group Pickup
Group Pickup

**4

**4

**4

**4

 
Call Voice Mail
Call Voice Mail
Call Voice Mail

*0

*0

*0

Forward All to Voicemail 1
Forward All to Voicemail 1
Forward All to Voicemail 1

**0

**0

**0

Forward All 1
Forward All 1
Forward All 1

**1 number

**1 number

**1 number

Disable Forward All
Disable Forward All
Disable Forward All

**2

**2

**2

Call Waiting
Call Waiting
Call Waiting

Hook flash to answer and switch between calls.

Hook flash to answer and switch between calls.

Hook flash to answer and switch between calls.

   
Blind Transfer
Blind Transfer

Call 1, hook flash, call 2, hang up.

Call 1, hook flash, #2, call 2, hang up

Supervised Transfer
Supervised Transfer

Call 1, hook flash, call 2, wait for call 2 to be answered, hang up

Call 1, hook flash, call 2, wait for call 2 to be answered, hook flash, #2

Conference
Conference

Call 1, hook flash, call 2, hook flash

Call 1, hook flash, call 2, hook flash, #3

 
Hang up Last Call

Call 1, hook flash, call 2, hook flash, #1

Hold

Call 1, hook flash, call 2; hook flash to toggle

1 When forward all is activated, users hear a distinctive dial tone to indicate that all incoming calls are currently being forwarded to a different directory number.


Understanding Caller ID Support

If you have activated caller ID on Cisco CallManager, the VG248 can collect that information and pass it on to analog phones. You can disable caller ID on a per port basis. You can also enable caller ID using different methods depending on the type of phone in use. This enables you to support caller ID on some analog phones and not on others (see the "Enabling Caller ID" section for details).

The VG248 supports the following caller ID standards:

Bellcore GR-30-CORE—North America

ETS 300 648 and ETS 300 659-1—Europe (excluding the United Kingdom)

British Telecom SIN227 and SIN 242—United Kingdom

When a call arrives, the VG248 sends the following information:

Time and date information

Calling number up to 18 digits when available, otherwise the reason why number is unavailable

Calling name up to 20 characters when available

Supported Analog Devices

The VG248 has a maximum ringer equivalency number (REN) load of three (3). Because some devices might have a REN load greater than one (1), you cannot necessarily connect three devices to the chain.

You should use analog devices designed to work in the country in which you are using the VG248. For example, if you are using the VG248 in the United Kingdom, you should use analog devices designed for use in that country.

These sections provide an overview of the types of analog devices supported by the VG248:

Analog Phones

Speakerphones

Private Line Automatic Ringdown Phones

Fax Machines

Modems

Analog Phones

The VG248 supports analog phones and the standard telephony features available on them.

Speakerphones

The VG248 performs line echo cancellation, but it does not perform acoustic echo cancellation. Speakerphones with built-in echo cancellation such as the Polycom-brand phones should work fine. However the voice quality might be unsatisfactory when using a speakerphone that does not perform acoustic echo cancellation itself.

Private Line Automatic Ringdown Phones

A telephone configured as a Private Line Automatic Ringdown (PLAR) telephone dials a pre-configured number when it goes off-hook. You cannot use PLAR phones to dial any other numbers. Telephones in hotel lobbies and airports are often configured in this way.

Cisco CallManager release 3.0 and later can be configured to support the PLAR phone feature for an IP phone or for an analog telephone connected to the VG248.

Fax Machines

The VG248 supports fax transmissions (or calls) over TCP/IP using either fax pass-through and Cisco fax relay modes. Fax pass-through sends the signals in an audio form similar to that used for modems, except echo cancellers are not disabled (see the "Modems" section for details). Cisco fax relay encodes the information in a different format which is converted back to analog fax signals by the other party in the call.

To use Cisco fax relay, the terminating gateway must also support Cisco fax relay. If necessary, you can disable Cisco fax relay (see the "Configuring Fax and Modem Settings" section for details).

Modems

The VG248 supports modems, which connect using pass-through mode. Using pass-through mode, modem traffic is transported over a channel similar to that used for a voice call. The modem pass-through channel uses G.711 and has the VG248 echo canceller and high-pass filter disabled to prevent interference with the tone-based signalling used by modems (see the "Configuring Fax and Modem Settings" section for details).

Using the VG248 with Voice Mail Systems

Simplified Message Desk Interface (SMDI) is a common method used by phone systems to provide voice mail systems with the information needed to intelligently process incoming calls. It is an industry-standard signaling protocol that supplies calling and called party identification and sets and clears Message Waiting Indicators (MWIs) through an RS-232 serial connection. MCI and Ericsson voice mail protocols are proprietary voice mail signalling protocols that function similarly to SMDI.

Using the VG248, you can integrate your existing analog voice mail systems (which are compatible with SMDI, MCI, or Ericsson voice mail protocols) and legacy PBX systems with Cisco CallManager.

The VG248 generates call information for all calls coming into any of the voice mail-enabled ports. The VG248 can also send and receive voice mail messages to and from other voice mail devices, such as other VG248 devices, a legacy PBX, or the legacy voice mail system.

The VG248 provides advantages to other methods used for integrating Cisco CallManager with analog voice mail systems, including:

Reliability for voice mail links using Cisco CallManager failover (see Figure 1-2).

Scalability by linking VG248 devices (see Figure 1-3).

Multiple voice mail systems can be used on a single cluster, by using one VG248 per voice mail system (see Figure 1-3).

A single voice mail system to be used by multiple clusters, by using one VG248 per cluster (see Figure 1-4).

A single voice mail system to be shared between Cisco  CallManager and a legacy PBX (see Figure 1-5).

Table 1-2 provides an overview of the tasks required to implement this integration.

Table 1-2 Voice Mail Configuration Tasks 

Task
Description
For More Information

Decide on an integration method

Choose one of the following methods:

Basic—connect a voice mail system to Cisco CallManager system via the VG248 (48 port maximum)

Chained—connect a voice mail system to Cisco CallManager system via multiple VG248 devices (more than 48 ports)

Multiplexing—connect a voice mail system to multiple Cisco CallManager clusters or legacy PBX systems

See the "Choosing a Configuration Option" section.

Connect the voice mail links to the VG248

Use Async 1 to connect to the voice mail system (any configuration) or voice mail source (chained or multiplexing configuration). Use Async 2 to connect VG248 devices together or to a legacy PBX system.

See the "Connecting the Voice Mail Links to the VG248" section on page 4-2.

Update service parameters in Cisco CallManager.

You should verify that the voice mail service parameters are properly configured to support the voice mail system.

See the "Configuring the Voice Mail Hunt Group in Cisco CallManager" section on page 5-8.

Add the MWI port to Cisco CallManager.

You must add a special port to Cisco CallManager that is used to set and clear MWI commands.

See the "Configuring the MWI Port Using Cisco CallManager" section on page 5-14.

Add the voice mail ports to Cisco CallManager.

You must add and configure the VG248 ports used for voice mail to the Cisco CallManager database.

See the "Configuring Voice Mail Ports in Cisco CallManager" section on page 5-15.

Update end-user phones.

You should update the voice mail settings for the end-user phones that are using the analog voice mail system.

See the "Configuring End-User Phones" section on page 5-18.

Configure the local voice mail settings on the VG248.

You must configure the local voice mail settings on the VG248. Some of these settings must match settings on the voice mail system or Cisco CallManager.

See Chapter 4, "Configuring Voice Mail Settings.".

Verify the status of the voice mail configuration.

You can check the status of the voice mail connections to help resolve any problems.

See the "Validating the SMDI Connection and Configuration" section.


Choosing a Configuration Option

You can use the VG248 to integrate analog voice mail systems (compatible with SMDI, MCI, or Ericsson voice mail protocols) with Cisco CallManager in different configurations depending on your needs:

Basic—if you need 48 or fewer voice mail ports and do not need to integrate with multiple Cisco CallManager clusters or a legacy PBX system.

Chained—if you need more than 48 voice mail ports; can be used with the multiplexing configuration.

Multiplexing—if you need to integrate with multiple Cisco CallManager clusters or with a legacy PBX system.

These sections provide additional information about these methods:

Basic Configuration

Chained Configuration

Multiplexing Configuration

Basic Configuration

In the basic configuration (see Figure 1-2), you can use a single VG248 device to connect up to 48 voice channels to a voice mail system. This configuration enables you to use your existing voice mail system and integrate it with Cisco CallManager using the appropriate voice mail protocol.

When using the VG248 in this configuration, you have a more flexible failover system than when using a single Cisco CallManager server for voice mail integration. When connecting the voice mail link directly to Cisco CallManager, if that Cisco CallManager system fails, the voice mail link goes down. The link cannot automatically be switched or transferred to another Cisco CallManager system. However, if you are using the VG248 and the primary Cisco CallManager system fails, the VG248 automatically switches to its backup Cisco CallManager system, and the voice mail link remains.

Configuration Tips

When configuring the VG248 using the basic configuration, refer to these tips. Note, however, that this is not a complete list of the items you must configure; these are tips specific to the basic configuration. Refer to the Chapter 4, "Configuring Voice Mail Settings" for a description of all voice mail configuration tasks.

The VG248 should be set to forward MWI commands to Cisco CallManager. See the "Forwarding MWIs to Cisco CallManager" section on page 4-7 for details.

If the VG248 is set to forward MWI commands to Cisco CallManager, you must set the MWI directory numbers in Cisco CallManager. See the "Identifying the Directory Number for Setting MWI on Cisco CallManager" section on page 4-9 and "Identifying the Directory Number for Clearing MWI on Cisco CallManager" section on page 4-9.

Figure 1-2 Basic Configuration of VG248 Voice Mail Integration

Chained Configuration

Each VG248 system enables you to use up to 48 ports for voice mail access. If you need more than 48 ports, you can use the chained configuration. The chained configuration (see Figure 1-3) enables you to connect multiple VG248 devices together, expanding the number of voice ports available for your voice mail integration.The voice mail information is shared and passed between the VG248 devices via the Async ports (see "Connecting the Voice Mail Links to the VG248" section on page 4-2 for details about the Async ports).

Configuration Tips

The tips that follow are not a complete list of the items you must configure; these are tips specific to the chained configuration. Refer to the Chapter 4, "Configuring Voice Mail Settings" for a description of all voice mail configuration tasks.

When using multiple VG248 systems, refer to these tips:

All VG248 systems connected together must be connected to a single voice mail system.

Verify that you identify the first voice mail port correctly on each VG248 device. See the "Identifying the First Voice Mail Port Number" section on page 4-5 for details.

The first VG248 per Cisco CallManager cluster should be set to forward MWI commands to Cisco CallManager. See the "Forwarding MWIs to Cisco CallManager" section on page 4-7 for details.

You do not need to set the VG248 systems to forward MWI commands along the Async 2 connection unless a second cluster or a legacy PBX is attached to the end of the voice mail chain. For example, if you are using the chained configuration in conjunction with the multiplexing configuration. See the "Forwarding MWIs to Async 2" section on page 4-8.

If a VG248 device is configured to forward MWI commands to Cisco CallManager, you must identify the MWI directory numbers used in Cisco CallManager. See the "Identifying the Directory Number for Setting MWI on Cisco CallManager" section on page 4-9 and "Identifying the Directory Number for Clearing MWI on Cisco CallManager" section on page 4-9.

Figure 1-3 Chained Configuration of VG248 Voice Mail Integration

Multiplexing Configuration

This method enables you to share a single voice mail system with multiple Cisco CallManager systems or another PBX system. Using the multiplexing configuration, you can integrate analog voice mail systems with multiple PBX systems, including:

Multiple Cisco CallManager clusters (see Figure 1-4)

Legacy PBX system and Cisco CallManager (see Figure 1-5)

Configuration Tips

The tips that follow are not a complete list of the items you must configure; these are tips specific to the multiplexing configuration. Refer to Chapter 4, "Configuring Voice Mail Settings" for a description of all voice mail configuration tasks.

When integrating voice mail links from more than one PBX system, refer to these tips:

If connecting to a legacy PBX, all VG248 devices should be set to forward MWIs to Async 2. See the "Forwarding MWIs to Async 2" section on page 4-8.

At least one VG248 per cluster should be set to forward MWI commands to Cisco CallManager. See the "Forwarding MWIs to Cisco CallManager" section on page 4-7.

If you are not using a legacy PBX, set the VG248 systems to forward MWI commands along the Async 2 connection. You do not need to set this on the VG248 system furthest away on the voice mail chain from the voice mail system. That VG248 device should be configured to forward MWI commands to Cisco CallManager. See the "Forwarding MWIs to Async 2" section on page 4-8.

If the VG248 is set to forward MWI commands to Cisco CallManager, you must set the MWI directory numbers in Cisco CallManager. See the "Identifying the Directory Number for Setting MWI on Cisco CallManager" section on page 4-9 and "Identifying the Directory Number for Clearing MWI on Cisco CallManager" section on page 4-9.

Figure 1-4 Multiplexing Configuration of VG248 Integration with Multiple Cisco CallManager Clusters

Figure 1-5 Multiplexing Configuration of VG248 Integration with Cisco CallManager and Legacy PBX

Supported Protocols

The VG248 supports several industry-standard and Cisco networking protocols required for voice communication over an IP network. Additionally, the VG248 supports protocols required for remote network management.

These sections provide an overview of the protocols supported by the VG248:

Data and Voice Protocols

Voice Mail Protocols

Network Management Protocols

Data and Voice Protocols

The VG248 supports the following data and voice communication protocols.

Internet Protocol (IP)—addresses and sends packets across the network.

Internet Group Management Protocol (IGMP)—used to report multicast group memberships

Trivial File Transfer Protocol (TFTP)—allows you to transfer files over the network.

HyperText Transfer Protocol (HTTP)—defines how messages are formatted and transmitted, and what actions Web servers and browsers should take in response to various commands.

File Transfer Protocol (FTP)—allows you to transfer files over the network.

Dynamic Host Configuration Protocol (DHCP)—dynamically allocates and assigns an IP address to network devices.

Real-Time Transport Protocol (RTP)—enables transporting of real-time data, such as interactive voice and video over data networks.

Skinny Client Control Protocol (SCCP)—enables communication between the VG248 and Cisco CallManager.

Voice Mail Protocols

The VG248 supports the following analog voice mail protocols:

Simplified Message Desk Interface (SMDI)—an industry-standard voice mail protocol used by the majority of analog voice mail systems for call integration

Message Center Interface (MCI)—a proprietary voice mail protocol used by NEC NEAX systems

Ericsson voice mail protocol—a voice mail protocol used by equipment manufactured by Ericsson

Network Management Protocols

The VG248 supports Simple Network Management Protocol (SNMP) and implements several industry-standard Management Information Bases (MIBs).

Understanding SNMP Support

The VG248 supports SNMP versions 1 and 2, enabling you to perform the following commands:

Get—Retrieve a specific node's value.

GetNext—Retrieve the first value present in the ordered tree whose node succeeds the one specified.

GetBulk—Retrieve bounded number of values whose nodes succeed, in the numerical ordering, the one specified. GetBulk is available only in SNMP v2.

Set—Set a specific value.

Understanding Trap Support

The VG248 generates the following general traps, as defined in RFC 1157:

Cold start—when the VG248 starts up and obtains an IP address

Warm start—when the VG248 changes IP addresses

Authentication failure—when an invalid community string is used

You must have set at least one network management station in order for the VG248 to generate traps. See the "Configuring Trap Settings" section on page 2-17 for details.

Understanding Supported MIBs

The VG248 supports the following MIBs.

RFC 1213

RFC 1213 is the basic MIB 2 specification which indicates the state of embedded interfaces and statistics for network protocols.

The VG248 supports RFC 1213 with the following caveats:

ifAdminStatus for the Ethernet interface cannot be written, and it is fixed at "up".

ifSpecific for all interfaces returns as "0, 0".

atTable cannot be written.

No "ip***" values can be written.

You cannot write to "tcpConnState" for an active TCP connection.

The VG248 does not implement the External Gateway Protocol (EGP).

Interface MIB

This MIB is defined in RFC 1573 and extends the range of information available about a device's interfaces from that provided by the ifTable in RFC 1213. The VG248 implements this MIB for its Ethernet interface and the 48 FXS interfaces. However, the octet or packet count values are not available for the FXS interfaces because they are not applicable to these interface types.

RMON

The VG248 implements the Ethernet Statistics group in Remote Monitoring (RMON), with the exception of "EtherStatsStatus." This is fixed at "valid" and cannot be written.

Cisco CDP MIB

Cisco Discovery Protocol (CDP) is a method that Cisco devices use to advertise their presence and to discover information about other nearby devices. The VG248 supports CDP and implements this MIB. You can enable or disable CDP on the VG248. See the "Enabling CDP" section on page 2-12 for details.

Cisco Process MIB

The Cisco Process MIB describes the processes currently running on the device. However, because the VG248 runs threads, rather than processes, the MIB is implemented with the following caveats:

The amount of memory allocated is not recorded on a per-thread basis. Therefore, cpmProcExtMemAllocated and cpmProcExtMemFreed are returned as 0.

All threads run at the same priority. Therefore, every process cpmProcExtPriority are returned as "normal."

It is not possible to change a process's priority, so attempts to write "cpmProcExtPriority" are unsuccessful.

Cisco Memory Pool MIB

This MIB allows detailed information to be retrieved for all memory pools present within a Cisco device. The VG248 implements this MIB, but because all dynamic memory management uses a single heap, the resulting table has one row, which is returned as "Processor".

Cisco EnvMon MIB

"EnvMon" refers to the on-board environmental monitor on the VG248 that monitors the internal voltage, power supply, temperature, and fan settings.

The VG248 routinely measures these values recording the information in the rows within the different tables:

ciscoEnvMonVoltageStatusTable—records voltage and power supply readings

ciscoEnvMonFanStatusTable—records fan status readings

ciscoEnvMonTemperatureStatusTable—records temperature settings

You can use this MIB to access these recorded values. Also, if the VG248 detects readings beyond the acceptable limits, the device generates warning messages. See the "Troubleshooting Hardware Errors" section for details.

Cisco Voice Interface MIB

This Cisco proprietary MIB (CISCO-VOICE-IF-MIB.my) allows access to voice interface parameters such as gain values and echo cancellation status. The VG248 implementation of this MIB provides read access only. You can configure the gain values using the VG248 interface (see the "Setting the Output Gain" section and the "Setting the Input Gain" section for details).

Cisco Analog Voice Interface MIB

This Cisco proprietary MIB (CISCO-VOICE-ANALOG-IF-MIB.my) allows access to interface parameters related to the analog ports. These parameters include hardware issues such as electrical impedance value and ring frequency and user factors such as whether an attached handset is currently on- or off-hook. The electrical impedance value and ring frequency is determined by the country code you set in the VG248 (see "Identifying the Country Code for VG248" section for details). You can modify the hook-flash timer using the VG248 interface (see "Changing the Hook Flash Timer for Analog Phones" section).