[Top] [Prev] [Next] [Bottom]

Using the Serial Interface Dialer

This document describes how to configure and monitor the Serial Interface Dialer. It includes the following sections:

Overview

Modem Requirements

Configuring the Serial Interface Dialer

Displaying the DIAL Monitoring Prompt

Manually Dialing the DIAL Circuit Interface

DIAL Commands

Overview

The Serial Interface Dialer (DIAL) handles the process of placing and receiving calls on the public switched telephone network. DIAL supports asynchronous and synchronous communication, including synchronous V.25 bis communication. Figure 1 shows a sample DIAL configuration.

Figure 1 Sample DIAL Configuration

You can set up the DIAL device

Terminology

 This discussion of the Serial Interface Dialer uses the following terminology.

Service

 Software capability that OpenROUTE offers. DIAL is a service.

Device

 Physical port on the router. You set up one DIAL configuration for each WAN device.

DIAL Circuit Interface

 A logical object over which the router sends or receives packets. Protocols, such as IP, IPX, and AppleTalk, route packets between interfaces.

Each WAN device on the router can have multiple DIAL circuit interfaces configured. Each DIAL circuit interface is a normal serial line network, running Point-to-Point Protocol (PPP).

DIAL circuit interfaces support the following forwarding protocols:

Figure 2 shows the relationship between the forwarding protocols, DIAL Circuit interfaces, WAN device, and the modem. The Serial Interface Dialer operates as the DTE (Data Terminal Equipment) and the modem operates as the DCE (Data Communications Equipment).

Figure 2 Relationship Between Routing Protocols, DIAL Circuit Interfaces, WAN Device, and Modem

Modem Requirements

To work with DIAL, your modem must support the following circuits and configuration.

Circuits Required

DIAL requires your modem to support the following V.24 circuits:

Modem Configuration Required

 DIAL support assumes that the modem configuration

Nx Networks also recommends

Configuring the Serial Interface Dialer

To set up a DIAL configuration, follow the steps in the next sections:

1. Configuring the DIAL Parameters

2. Adding a Modem Definition

3. Creating Chat Scripts (optional)

4. Setting Serial Line Parameters

5. Setting DIAL Circuit Configuration Parameters

6. Limiting Dial-on-Demand (optional)

7. Restarting the Router

PPP is the protocol that runs over DIAL. To set up PPP features such as PAP, CHAP, MP, data compression, or call-back, see Using PPP Interfaces.

Before You Begin

To configure DIAL, you need the following information:

Configuring the DIAL Parameters

 The DIAL parameters, which you enter at the Dial Config <WAN#> or DIAL <WAN#> prompt, apply to all DIAL circuit interfaces on a WAN device.

1. If necessary, set the data link of the serial interface to PPP. 

Config>set data-link ppp
Interface Number [0]? 1
2. Enable DIAL on the WAN device.

If your router has multiple WAN devices, the software prompts you for a device name. To see a list of devices on your router, enter list devices. 

Config>enable dial 
Device name? WAN2
3. Display the circuit configuration prompt. Enter network followed by the number of the interface you want to configure. To see a list of interfaces, enter list interfaces. 

Config>network
What is the network number [0]? 1

Circuit Configuration

Circuit Config <NET-1>
4. Display the DIAL configuration prompt. 

Circuit Config <NET-1>dial

Serial Interface Dialer Configuration

DIAL Config <WAN>
5. Add an address for each potential destination. 

DIAL Config <WAN>add address
Address name (1-23 characters)? seattle
Network dial address (1-31 digits)? 1-555-3421
6. Set optional DIAL parameters. The default parameters work for most configurations.

To . . . Use this Set
command . . . 		The default is . . .
Limit calls to an address that is inaccessible or refuses calls.

 retries-no-answer

timeout-no-answer

 1 retry

0 (which causes the modem to control the timeout)

Set the amount of time the router waits to place a call after disconnecting the previous call.

disconnect-timeout

 2 seconds

Set the amount of time allowed to establish a call.

 connect-timeout

 60 seconds

Adding a Modem Definition

The modem definition supplies commands to configure the modem to dial, accept connections, and disconnect. It also tells the router how the modem is configured and what result codes to expect from the modem. The following steps show how to add a modem definition to your DIAL configuration. For more information on these commands, see Modem Definition Commands.

1. Add a modem definition. Give it a name and set the modem type to one of the options: configurable, non-configurable, or v25bis.

For example, to add a configurable modem definition, enter 

DIAL Config <WAN> add modem configurable
Modem name (1-23 characters)? usr288
2. Display the Modem Config> prompt. At this prompt, you can modify the modem definition.

Enter modem, followed by the modem name that you added in step 1. 

DIAL Config <WAN>modem
Modem name (1-23 characters)? usr288
Modem Config>
3. Display the default modem definition and compare it to your modem's configuration. If your modem configuration does not match these parameters, you need to change these settings. 

Modem Config>list


Configuration of Modem:


Options
-------
Initialization:  Enabled
Answer:          Disabled
Dial:            Enabled
Disconnect:      Disabled
Carrier Wait:    Disabled
Ready Wait:      Disabled


Commands
--------
Initialization:  ATE0M0S0=1\r
Answer:          ATA\r
Dial Prefix:     ATDT
Dial Suffix:     \r
Disconnect:      ATH\r
Escape Sequence: +++


Guard Time:      50  


Result Codes
------------
BUSY:            BUSY
CONNECT:         CONNECT
ERROR:           ERROR
NO ANSWER:       NO ANSWER
NO CARRIER:      NO CARRIER
NO DIALTONE:     NO DIALTONE
OK:              OK
RING:            RING

To enable or disable the Options, use the enable and disable modem configuration commands.

To change Commands or Result Codes, use the set modem configuration commands.

4. When you are done modifying your modem definition, return to the DIAL Config <WAN> prompt. 

Modem Config>exit
DIAL Config <WAN>
5. Set the modem definition to use with this DIAL device. 

DIAL Config <WAN>set modem
Modem name?usr288

Creating Chat Scripts

Chat scripts allow a DIAL circuit interface to communicate with remote destinations that require login authentication. You can create chat scripts for DIAL circuit interfaces to use on outgoing calls over asynchronous lines. Chat scripts let you specify the dialog, consisting of queries and responses, expected to take place between the DIAL circuit interface and the remote router. See Chat Script Commands for complete information on these commands.

Notes:

The following steps show an example of how to create a chat script.

1. Add a chat script and give it a descriptive name. 

DIAL Config <WAN>add chat-script
Chat script name? seattle
2. Display the chat script configuration prompt. At this prompt, you create or modify the contents of the script.

Enter chat-script, followed by the name of the chat script that you added in step 1. 

DIAL Config <WAN>chat-script
Chat script name?seattle
Chat Config>
3. Specify the first string of characters that the circuit expects to receive as a query from the remote destination. 

Chat Config>receive
Receive string []?Login:
4. Optionally, you can insert a delay in the chat script before a transmit line, and the circuit waits this number of seconds before it sends the string in the transmit line to the remote router. 

Chat Config>wait
Wait in seconds [0]? 5
5. Specify the string of characters that the circuit sends to the remote destination in response to the query the circuit receives. In this case, in response to Login:.

Note: You must enter a \r (carriage return character) at the end of your transmit string or the router does not send the string. 

Chat Config>transmit
Transmit string []?boston\r
6. Enter the next string of characters that the circuit expects to receive as a query from the destination. 

Chat Config>receive
Receive string []?password:
7. Enter the next string of characters that the circuit sends to the destination in response to the query the circuit receives. In this case, in response to password:. 

Chat Config>transmit
Transmit string []?abracadabra\r
8. Continue using the receive and transmit commands until you are done specifying the entire chat script.

9. To see the chat script that you created, enter list. 

Chat Config>list
Configuration of Chat Script: seattle


1   receive  Login:
2   wait     5
3   transmit boston\r
4   receive  password:
5   transmit abracadabra\r
10. If necessary, use the following chat script commands.

11. When you are done creating or modifying your script, return to the DIAL Config <WAN> prompt. 

Chat Config>exit
DIAL Config <WAN>
12. Follow step 5 in Setting DIAL Circuit Configuration Parameters to assign the chat script to a DIAL circuit interface.

Setting Serial Line Parameters

 This section describes the Serial Line parameters that you can set. These parameters apply to all DIAL circuit interfaces configured on the WAN device.

1. Display the Serial configuration prompt. 

Circuit Config <NET-1> sl
Serial Line Configuration

Serial Config <WAN>
2. The default line discipline is synchronous (sync). To use asynchronous, set the line discipline to async. 

Serial Config <WAN>set line-discipline async
3. If the line discipline is

Parameter Default
Cable Type*

 RS-232 DTE

Clocking*

 External

Encoding

 NRZ

Frame size

 2048 bytes

Idle

 Flag

Speed

 64,000 bps

Transmit delay

 0

* Not configurable on all platforms. Some platforms automatically detect the cable type and set clocking to internal or external, based on whether the cable is DTE or DCE.

Parameter Default
Cable Type*

 RS-232 DTE

Databits

 8

Frame size

 2048

Parity

 None

Speed

 57600 bps

Stopbits

 1

* Not configurable on all platforms. Some platforms automatically detect the cable type.

Setting DIAL Circuit Configuration Parameters

You can set up multiple circuit interfaces for each DIAL device. The circuit configuration includes a remote destination, which chat script to use, whether the connection is dial-on-demand, and whether the circuit accepts inbound calls, places outbound calls, or both.

Note: Nx Networks recommends that the maximum number of dial interfaces you configure on a GT 60 Series or GT 70 Series is eight. Adding more than eight dial interfaces can cause the router to exhaust available memory and crash during initialization. If this happens, you have to clear your configuration before reloading, unless you saved a configuration with no more than eight dial interfaces.

1. Display the Circuit Config> prompt.

Enter network followed by the interface number of the DIAL circuit interface. To see a list of interfaces, enter list interfaces at the Config> prompt. 

Config>network
What is the network number [0]? 1

Circuit Configuration
Circuit Config <NET-1>
2. Specify the address name of the remote router to which the DIAL circuit interface is to connect.

Enter one of the names you defined using add address at the DIAL Config <WAN>. 

Circuit Config <NET-1> set destination
Assign destination address name []? seattle
3. Set up the circuit to dial on demand or to always remain active. To do so, specify a timeout period using the set idle command. If there is no traffic over the circuit for this time period, the circuit hangs up. Zero (0) causes the connection to remain established indefinitely. 

Circuit Config <NET-1>set idle
Idle timer (seconds, 0 means always active) [0]? 180
4. Set up the circuit to initiate outbound calls, accept inbound calls, or both initiate and accept calls. To avoid a conflict when both ends of the link attempt to establish a call at the same time, set up the circuit at one end of the link to accept inbound calls only, and set up the circuit at the other end of the link to initiate outbound calls only.

Use the disable or enable commands. The options are inbound, outbound, or any-inbound. For example: 

Circuit Config <NET-1>enable outbound
5. If this circuit is to use a chat script, assign a chat script that you created in the DIAL configuration. 

Circuit Config <NET-1> set chat-script
Assign chat script name? seattle

Note: To turn off use of the chat script, enter set chat-script off at this prompt.

6. Optionally, you can create a list of up to eight remote routers from which this circuit accepts calls. This list is in addition to the router named with the set destination command. 

Circuit Config <NET-1> set access-list
Enter 1st name:? new york
Enter 2nd name:? pittsburg
Enter 3rd name:?
7. To see your circuit configuration, enter list. 

Destination Name: seattle
Chat Script Name: seattle
Outbound calls:   Allowed
Inbound calls:    Allowed
Idle Time:        180 seconds
Access List:      seattle (destination), new york, pittsburg
You can set up additional DIAL circuit interfaces, each with its own destination, chat script, inbound or outbound call set up, idle timer, and access list. To do so, add a PPP interface and repeat the steps in this section for each new DIAL circuit interface. 

Config>add interface ppp
Adding interface 3 linked to base device WAN.

Limiting Dial-on-Demand

 Most protocols send out periodic routing information that could cause the router to dial out each time it sends routing information over dial-on-demand circuits. To limit periodic routing updates, configure IP to use only static routes and disable the routing protocols (RIP, OSPF) over the dial circuits. Configure IPX for low-frequency updates or change updates so that it sends broadcast messages at specified intervals, when there is data to send, or if there is a problem. You should also enable IPX Keepalive filtering, which prevents keepalive and serialization packets from continually activating a dial-on-demand link.

Restarting the Router

When you are finished configuring the router, restart it to activate the new configuration.

1. Return to the * prompt by pressing Ctrl P.

2. Enter restart.

Displaying the DIAL Monitoring Prompt

 At the DIAL monitoring prompt, you can display statistics for the DIAL device, show the number of completed and attempted calls, display the status of the DIAL device, and list the current configuration of the DIAL device.

To display the DIAL monitoring prompt.

1. At the * prompt, enter monitor. 

*monitor
Monitor>
2. Enter network followed by the number of a DIAL interface. Enter list interface at the Monitor> prompt to see a list of interface numbers. 

Monitor>network 1

Circuit <NET-1>
3. Enter dial. 

Circuit <NET-1> dial

Serial Interface Dialer Console

DIAL <WAN>

Manually Dialing the DIAL Circuit Interface

 To set up the DIAL circuit interface to dial out on command, disable the interface. When you are ready to dial out, enable the DIAL circuit interface. If you have the idle timer set to 0 (zero), the router dials out immediately. Otherwise, it waits until there is data to send.

To disable the DIAL circuit interface, enter disable interface followed by the number of the interface. If there is an active call, the interface drops the call. To see a list of interface numbers, enter list interface at the Monitor> prompt. For example:

Monitor>list interfaces
                 Self-Test  Self-Test   Maintenance
 Nt   Interface    Passed     Failed       Failed
 0      Eth/0        0          0            0
 1      PPP/0        0          0            0
 2      PPP/1        0          0            0
Monitor>disable interface
Interface number [0]? 2
To enable the interface, enter test interface followed by the number of the DIAL circuit interface. 

Monitor>test interface
Interface number [0]? 2

DIAL Commands

 This section describes the DIAL commands.

Press Space twice after you type a command to display the available parameters for each command. Enter help for information about using the command line interface.

[C] means the command is available at the DIAL Config <WAN#> prompt.

[M] means the command is available at the DIAL <WAN#> prompt.

Table 1 DIAL Commands

Command Function
Add [C] Adds dial addresses, chat scripts, or modem definitions to the DIAL configuration.

Calls [M] Lists the number of completed, refused, and blocked connections that this DIAL device made.

Chat-Script [C] Displays the configuration prompt for the chat script that you specify.

Circuits [M] Shows the status of DIAL circuit interfaces.

Copy Chat-Script [C] Copies a chat script, creating a duplicate chat script with a new name.

Delete [C] Deletes dial addresses, chat scripts, or modem definitions from the DIAL configuration.

Exit [C] [M] Returns to the previous prompt.

List [C] Displays a list of dial addresses, chat scripts, and modems that you configured. Also displays the current parameters for this interface.

Modem [C] Allows you to configure a modem definition.

Modem-Info [M] Reports hardware, firmware, and country information on the GTX 1000 modular modem.

Parameters [M] Shows the current state of the DDS module's back-to-back master operation.

Set [C] Sets timeouts, number of retries, and the modem definition for the DIAL configuration.

Add [C]

Adds dial addresses, chat scripts, and modem definitions to the DIAL configuration.

Syntax: add

address
chat-script
modem

address

Adds dial address information for a remote site. Add an address for each destination to which you expect to connect. To add more than one network dial address for each address name, repeat the command using the same address name.

Any DIAL circuit interface on the router can use an address. After you add an address, assign the address name that a particular DIAL circuit interface uses by entering set destination at the Circuit Config <NET-#> prompt.

Example: add address

Address name (1-23 characters)? portland
Network dial address (1-31 digits)? 1-555-2323
Address name

 A description of the address. Enter up to 23 ASCII characters.

Network dial address

 Telephone number of the remote site. Enter up to 31 characters in the valid format of the connected modem.

chat-script name

Adds a chat script to your configuration.

Note: You can use chat scripts only over asynchronous lines.

Any DIAL circuit interface on the router can use a chat script. After you add a chat script, assign the script that a particular DIAL circuit interface uses by entering set chat-script at the Circuit Config <NET-#> prompt.

For the chat script name, enter up to 23 printable ASCII characters.

After you add a chat script, configure it by entering chat-script. See Creating Chat Scripts.

Example: add chat-script

Chat script name? seattle

modem

Adds a modem definition to your DIAL configuration. For modem type, enter configurable, non-configurable, or v25bis.

For the modem name, enter up to 23 printable ASCII characters.

After you add a modem definition, you can configure configurable modem definitions by entering the modem command followed by the name of the modem definition. See Adding a Modem Definition for steps to configure a modem definition.

Once you add a modem, enter set modem to specify the name of the modem definition to be used with this DIAL device.

Example: add modem configurable

Modem name (1-23 characters)?usr288

Calls [M]

Lists the number of attempted and completed connections that this DIAL device made since the last time statistics were reset on the router.

Syntax: calls

Example: calls

                                       Refused   Refused
Remote Site              In     Out    Remotely  Locally  Blocked
Seattle                  0      0      0         0        0
Remote Site

 Network address name of the destination.

In

 Inbound connections accepted for this destination.

Out

 Outbound connections completed for this destination.

Refused Remotely

 Connections that this interface initiated and the remote destination refused.

Refused Locally

 Inbound connection attempts that this interface refused.

Blckd

 Connection attempts that the router blocked. The router blocks connection attempts if the local interface is already in use, the interface reaches the maximum number of retries to a nonresponsive address, or a modem is not responding.

Chat-Script [C]

Displays the configuration prompt for the chat script that you specify. For steps to configure a chat script, see Creating Chat Scripts. For a description of the chat commands, see Chat Script Commands.

Syntax: chat-script name

Example: chat-script

Chat script name []? seattle
Chat Config>

Copy Chat-Script [C]

Creates a duplicate chat script by copying a chat script and giving it a new name.

Syntax: copy

Example: copy chat-script

Chat script name? seattle
Name of new chat script? fairbanks

Circuits [M]

Shows the status of the DIAL circuit interfaces.

Syntax: circuits

Example: circuits

State               Reason               Duration
Connected           Up                   6:58:17
State

 Current state of the DIAL circuit interface.

Idle— Initial state of the DIAL interface.
Wait to dial— Waiting for the modem to respond to DTR before dialing.
Dialed— Dial commands were issued. Waiting for DCD.
Wait to accept— Waiting for the modem to respond to DTR before accepting the incoming call.
Accepted— The interface accepted the incoming call and is waiting for DCD.
Connected— DCD has come up.
Clearing— The interface is dropping the connection.
V.25 bis modems can be in the following states:

Accepted— The modem turned off Ring Indicator to indicate that DIAL accepted the incoming call.
Accepting— The modem turned on CTS to indicate that it recognizes that DIAL turned on DTR to accept the incoming call.
Answered— The remote site answered the outbound call. The modem turned off CTS.

Clearing— The call is being disconnected.
Connected— The modem turned on both DSR and CTS.
Connecting— The modem turned on DSR.
Idle— No connection exists. DTR is off.
Incoming— DIAL detected an incoming call. The modem turned on Ring Indicator. DIAL turned on DTR to accept the call.
Modem Ready— Initiating an outbound call. DTR is on. The modem turned on CTS. DIAL is now dialing the remote site.
Ready to Dial— Initiating an outbound call. DTR is on. DIAL is waiting for the modem to turn on CTS.
Seized— DIAL accepted the incoming call. The modem turned off CTS before turning on DSR.
Reason

 Reason for the current state.

Up— Currently connected.
Connecting— Connection in progress.
Disconnecting— Disconnection in progress.
Down— Currently disconnected.
Duration

 Length of time the interface has been in the current state.

Delete [C]

Deletes a specific dial address, all dial addresses for an address name, a chat script, or a modem definition from the DIAL configuration.

Syntax: delete

address
all-addresses
chat-script
modem

address

Deletes a specific address that you added using the add address command.

Example: delete address

Address name? portland
Network dial address? 1-555-2323

all-addresses

If you entered more than one network dial address for an address name, use this command to delete all dial addresses for that address name.

Example: delete all-addresses

Address name? portland

chat-script

Deletes a chat script.

Example: delete chat-script

Chat script name? seattle

modem

 Deletes a modem definition.

Example: delete modem

Modem name?usr288

Exit [C] [M]

Returns to the previous prompt.

Syntax: exit

Example: exit

Circuit Config>

List [C]

Displays a list of dial addresses, chat scripts, and modems that you configured. Also displays the current DIAL parameters.

Syntax: list

addresses
chat-scripts
modems
parameters

addresses

Displays dial addresses that you added using the add address command.

Example: list addresses

Address assigned name             Network Address
---------------------             ---------------
portland                          1-555-2323

chat-scripts

Displays the names of all chat scripts that you added.

Example: list chat-scripts

Chat Script Name
----------------
boston
seattle

modems

Displays the modem definitions that you created.

Example: list modems

Modem Name                    Modem Type
----------                    ----------
usr288                      Configurable
microcom	                    Non-configurable

parameters

Displays the current DIAL configuration.

Example: list parameters

         Serial Interface Dialer Configuration

Modem Name:                   usr288

Non-Responding Addresses
------------------------
Retries:                      1
Timeout:                      0 seconds

Call Timeouts
-------------
Connect:                      60 seconds
Disconnect:                   2 seconds

Modem [C]

Displays the configuration prompt for the modem definition that you specify. See Adding a Modem Definition for steps to configure a modem definition. See Modem Definition Commands for a description of the modem commands.

You cannot configure V.25 bis modems.

Syntax: modem

Example: modem

Modem name (1-20 characters)? usr88
Modem Config>

Modem-Info [M]

 If you have a GTX 1000 with an optional modem module installed, this command appears in the command menu. Reports hardware, firmware, and country information describing the modem module installed in your GTX 1000.

Syntax: modem-info

Example: modem-info

Parameters [M]

Displays the active parameters for this DIAL device. This is the same information the list parameters configuration command displays.

Syntax: parameters

Example: parameters

         Serial Interface Dialer Parameters

Modem Name:                   usr288

Non-Responding Addresses
------------------------
Retries:                      1
Timeout:                      0 seconds

Call Timeouts
-------------
Connect:                      60 seconds
Disconnect:                   2 seconds

Set [C]

Sets timeouts, number of retries, and the modem definition for the DIAL configuration.

Syntax: set

connect-timeout
disconnect-timeout
modem
retries-no-answer
timeout-no-answer

connect-timeout

Sets the number of seconds allowed to complete a call. The range is 0 to 65535 seconds, and the default is 60. Zero (0) causes the modem to control the connection timeout.

Example: set connect-timeout

Connect Timeout (0-65535 Seconds, 0 means no timeout)[60]?

disconnect-timeout

Sets a timer that starts when the disconnect process begins. If a DIAL interface has not received a signal from the modem indicating the connection is complete when this timer expires, the interface initiates further calls. The range is 0 to 65535 seconds, and the default is 2. Zero (0) causes a DIAL interface to wait for the modem to complete and signal the disconnect before it initiates further calls.

Example: set disconnect-timeout

Disconnect Timeout (0-65535 sec, 0 means no timeout)[2]?

modem

Specifies the name of the modem definition to be used with this DIAL device. See Adding a Modem Definition for information on creating modem definitions.

Example: set modem

Modem name []?

retries-no-answer

Sets the maximum number of calls a DIAL interface attempts to make to a nonresponsive address during the timeout period specified by set timeout-no-answer. The range is 0 to 10, and the default is 1. Some telephone service providers impose restrictions on automatic redialing devices to limit the number of successive calls to an address that is inaccessible or that refuses those calls. Government regulations may also impose limits on the modem manufacturer that would supersede this parameter.

Example: set retries-no-answer

Retries-no-answer (0-10, 0 means no limit) [1]?

timeout-no-answer

After a DIAL interface reaches the maximum number of retries to a nonresponsive address, specified by set retries-no-answer, it does not make further calls to that address until this time expires. This timeout period begins when the router attempts the first call to an address. The range is 0 to 65535, and the default is 0. Zero (0) causes the modem to control the timeout period.

Example: set timeout-no-answer

Timeout-no-answer (0-65535 Seconds, 0 means no timeout) [0]?


[Top] [Prev] [Next] [Bottom]

Copyright © 2000, Nx Networks. All rights reserved.