ISDN BRI Backup on the Cisco MC3810

Feature Summary

The Cisco MC3810 provides an ISDN Basic Rate Interface (BRI) on the Multiflex Trunk module (MFT) that can be used as a backup interface for data only.

Benefits

The ISDN BRI backup feature allows flexibility in the Cisco MC3810 network design, in which the BRI interface on the MFT can be used as a backup for serial ports accessing the network.

Restrictions

The standard Cisco IOS ISDN implementation is supported with the following exceptions:

Voice traffic is not supported on the ISDN BRI backup interface.
ATM traffic is not supported over the ISDN BRI backup interface.
The ISDN BRI backup interface does not act as a standby to answer a call until the backup mode is triggered. The ISDN BRI backup interface does not make calls or receive calls until the primary interface has gone down.
The ISDN BRI backup interface cannot be used for a leased-line service in which there is no call setup or teardown.
ISDN semipermanent connections between the BRI interface and the 1TR6 basic rate switch are not supported.
The Cisco MC3810 might take longer than other Cisco products to switch from the T1/E1 interface to the BRI backup interface.

For more information about standard Cisco ISDN BRI configuration, see the Dial Solutions Configuration Guide.

Note When the BRI backup interface is active, only one channel group can be supported. In this case, a single Frame Relay or ATM channel group is supported; however, no voice groups or Time Division Multiplexing (TDM) groups can be supported when the BRI backup interface is active.

Platforms

This feature is supported on the Cisco MC3810 beginning in Cisco IOS Release 12.0(1)XA.

Supported MIBs and RFCs

None.

Configuration Tasks

To configure the ISDN BRI backup interface, complete the following steps beginning in global configuration mode:

Step Command Purpose

1

isdn switch-type switch-type

Configure the global ISDN switch type to match the service provider switch type. For a list of keywords, refer to Table 1.

2

isdn tei [first-call | powerup]

Configure when the ISDN Terminal Endpoint Identifier (TEI) negotiation occurs.

The first-call option is primarily used in European ISDN switch types, such as NET3 networks. The powerup option should be used in most other locations.

3

interface bri 0

Enter interface configuration mode for the BRI backup interface.

ISDN BRI backup is supported only on interface bri 0.

4

ip address ip-address mask

Enter the IP address and subnet mask for the BRI backup interface.

5

Configure the appropriate encapsulation on the BRI backup interface by entering one of the following commands:

encapsulation ppp

Enable Point-to-Point Protocol (PPP) encapsulation on the BRI backup interface.

encapsulation frame-relay

Enable Frame Relay encapsulation on the BRI backup interface.

encapsulation hdlc

Enable High-Level Data Link Control (HDLC) encapsulation on the BRI backup interface.

6

isdn switch-type switch-type

Configure the interface ISDN switch type to match the service provider switch type. The interface ISDN switch type overrides the global ISDN switch type on the interface.

For a list of keywords, refer to Table 1.

7

isdn answer1 [called-party-number]
[:subaddress]

(Optional) Configure called party number verification to verify a called-party number or subaddress number in the incoming setup message.

8

isdn not-end-to-end [56 | 64]

(Optional) Configure the speed for incoming calls not recognized as ISDN end-to-end.

9

isdn fast-rollover-delay seconds

(Optional) Configure a fast rollover delay.

10

isdn sending-complete

(Optional) Configure the BRI backup interface to include the Sending Complete information element in the outgoing call Setup message. Used in some geographic locations, such as Hong Kong and Taiwan, where the sending complete information element is required in the outgoing call setup message.

Step	Command	Purpose
1	isdn switch-type switch-type	Configure the global ISDN switch type to match the service provider switch type. For a list of keywords, refer to Table 1.
2	isdn tei [first-call \| powerup]	Configure when the ISDN Terminal Endpoint Identifier (TEI) negotiation occurs. The first-call option is primarily used in European ISDN switch types, such as NET3 networks. The powerup option should be used in most other locations.
3	interface bri 0	Enter interface configuration mode for the BRI backup interface. ISDN BRI backup is supported only on interface bri 0.
4	ip address ip-address mask	Enter the IP address and subnet mask for the BRI backup interface.
5	Configure the appropriate encapsulation on the BRI backup interface by entering one of the following commands:
	encapsulation ppp	Enable Point-to-Point Protocol (PPP) encapsulation on the BRI backup interface.
	encapsulation frame-relay	Enable Frame Relay encapsulation on the BRI backup interface.
	encapsulation hdlc	Enable High-Level Data Link Control (HDLC) encapsulation on the BRI backup interface.
6	isdn switch-type switch-type	Configure the interface ISDN switch type to match the service provider switch type. The interface ISDN switch type overrides the global ISDN switch type on the interface. For a list of keywords, refer to Table 1.
7	isdn answer1 [called-party-number] [:subaddress]	(Optional) Configure called party number verification to verify a called-party number or subaddress number in the incoming setup message.
8	isdn not-end-to-end [56 \| 64]	(Optional) Configure the speed for incoming calls not recognized as ISDN end-to-end.
9	isdn fast-rollover-delay seconds	(Optional) Configure a fast rollover delay.
10	isdn sending-complete	(Optional) Configure the BRI backup interface to include the Sending Complete information element in the outgoing call Setup message. Used in some geographic locations, such as Hong Kong and Taiwan, where the sending complete information element is required in the outgoing call setup message.

Table 1: ISDN Switch Types
Country ISDN Switch Type Description

Australia

basic-ts013

Australian TS013 switches

Europe

basic-1tr6

German 1TR6 ISDN switches

basic-nwnet3

Norwegian NET3 ISDN switches (phase 1)

basic-net3

NET3 ISDN switches (UK and others)

vn2

French VN2 ISDN switches

vn3

French VN3 ISDN switches

Japan

ntt

Japanese NTT ISDN switches

New Zealand

basic-nznet3

New Zealand NET3 switches

North America

basic-5ess

AT&T basic rate switches

basic-dms100

NT DMS-100 basic rate switches

basic-nil1

National ISDN-1 switches

**Table 1: ISDN Switch Types**
Country	ISDN Switch Type	Description
Australia	basic-ts013	Australian TS013 switches
Europe	basic-1tr6	German 1TR6 ISDN switches
	basic-nwnet3	Norwegian NET3 ISDN switches (phase 1)
	basic-net3	NET3 ISDN switches (UK and others)
	vn2	French VN2 ISDN switches
	vn3	French VN3 ISDN switches
Japan	ntt	Japanese NTT ISDN switches
New Zealand	basic-nznet3	New Zealand NET3 switches
North America	basic-5ess	AT&T basic rate switches
	basic-dms100	NT DMS-100 basic rate switches
	basic-nil1	National ISDN-1 switches

Verifying the Configuration

To verify the ISDN BRI interface configuration, complete the following steps in privileged EXEC mode:

Step Command Purpose

1

show interfaces bri 0

Display information about the physical attributes of the ISDN BRI B and D channels.

2

show controllers bri 0

Display protocol information about the ISDN B and D channels.

3

show isdn {active | history | memory | status | timers}

Display information about calls, history, memory, status, and Layer 2 and Layer 3 timers.

4

show dialer interface bri number

Obtain general diagnostic information about the specified interface.

Step	Command	Purpose
1	show interfaces bri 0	Display information about the physical attributes of the ISDN BRI B and D channels.
2	show controllers bri 0	Display protocol information about the ISDN B and D channels.
3	show isdn {active \| history \| memory \| status \| timers}	Display information about calls, history, memory, status, and Layer 2 and Layer 3 timers.
4	show dialer interface bri number	Obtain general diagnostic information about the specified interface.

Command Reference

All the commands required to configure this feature are standard Cisco IOS commands in Cisco IOS Release 12.0. For information about these commands, see the Dial Solutions Command Reference.