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Cisco IOS Dial Services Configuration Guide: Network Services, Release 12.1
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About the Cisco IOS Software Documentation
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Using Cisco IOS Software
- Part 1: Large-Scale Dial Solutions
- Part 2: Cost-Control Solutions
- Part 3: Virtual Private Networks
- Part 4: X.25 on ISDN Solutions
- Part 5: Telco Solutions
- Part 6: Dial-Related Addressing Services
- Part 7: Interworking Dial Access Scenarios
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Table Of Contents
X.25-over-D-Channel Logical Interface
Outbound Circuit-Switched X.25 Support over a Dialer Interface
X.25 on ISDN Configuration Task List
Configuring X.25 on the ISDN D Channel
X.25 on ISDN Configuration Examples
X.25 on ISDN D-Channel Configuration
Outbound Circuit-Switched X.25
Configuring X.25 on ISDN
This chapter describes how to configure X.25 over ISDN. It includes the following main sections:
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X.25 on ISDN Configuration Task List
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For a complete description of the commands mentioned in this chapter, see the Cisco IOS Dial Services Command Reference publication. To locate documentation of other commands that appear in this chapter, use the command reference master index or search online.
X.25 on ISDN Overview
BRI is an ISDN interface, and it consists of two B channels (B1 and B2) and one D channel. The B channels are used to transfer data, voice, and video. The D channel controls the B channels.
ISDN uses the D channel to carry signal information. ISDN can also use the D channel in a BRI to carry X.25 packets. The D channel has a capacity of 16 kbps, and the X.25 over D channel can utilize up to 9.6 kbps.
X.25-over-D-Channel Logical Interface
When X.25 on ISDN is configured, a separate X.25-over-D-channel logical interface is created. You can set its parameters without disrupting the original ISDN interface configuration. The original BRI interface will continue to represent the D, B1, and B2 channels.
Because some end-user equipment uses static terminal endpoint identifiers (TEIs) to access this feature, static TEIs are supported. The dialer understands the X.25-over-D-channel calls and initiates them on a new interface.
X.25 traffic over the D channel can be used as a primary interface where low-volume, sporadic interactive traffic is the normal mode of operation. Supported traffic includes the Internet Protocol Exchange (IPX), AppleTalk, transparent bridging, Xerox Network Systems (XNS), DECnet, and IP.
This feature is not available on the ISDN PRI.
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Outbound Circuit-Switched X.25 Support over a Dialer Interface
Current Cisco IOS software enables circuit-switched X.25 clients—PAD, X.25 switching, and Qualified Logical Link Control (QLLC)—to initiate calls and dynamically bring the X.25 context (which runs the X.25 protocol) up or down as needed. This capability allows packet-switched traffic over ISDN.
In earlier releases of the Cisco IOS software, X.25 circuit-switched clients were required to do an X.25 route lookup to forward a call. If the lookup resulted in a route to a dialer interface, the client would check the X.25 protocol state on the dialer interface. If the interface was not already bound to run the X.25 protocol, the software would reroute the call instead of bringing up a link and running the X.25 protocol. With this new feature, the X.25 context is dynamically created on demand and then removed when the X.25 session is cleared on the dialer interface.
For dialer profile interfaces, the X.25 context is created on the dialer interface, because X.25 protocol functions run on the dialer interface itself. Member links act like forwarding devices, because their topmost interface runs the actual encapsulated protocol. But for legacy dialer interfaces, the X.25 context is created on the member links once they come up and bind to a dialer.
There are no specific configuration tasks required to enable outbound circuit-switched X.25 support. See the "Outbound Circuit-Switched X.25" example in the section "X.25 on ISDN Configuration Examples" at the end of this chapter for an example of how to make use of this feature in your network.
X.25 on ISDN Configuration Task List
You can configure X.25 on ISDN in three ways:
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Configuring X.25 on the ISDN D Channel
To configure an ISDN BRI interface (and create a special ISDN interface) to carry X.25 traffic on the D channel, use the following commands beginning in global configuration mode:
The last step is to configure the X.25-over-ISDN interface for X.25 traffic. See the chapter "Configuring LAPB and X.25" in the Cisco IOS Wide-Area Networking Configuration Guide for the commands and tasks.
The new X.25-over-ISDN interface is called interface bri number:0 in configuration displays. It must be configured as an individual X.25 interface. For information about configuring an interface for X.25 traffic, see the Cisco IOS Wide-Area Networking Configuration Guide.
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If you want to remove the X.25-over-ISDN interface later, use the no isdn x25 dchannel command.
See the section "X.25 on ISDN D-Channel Configuration" at the end of this chapter for a configuration example.
X.25 on ISDN Configuration Examples
This section illustrates X.25 on ISDN with the following examples:
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X.25 on ISDN D-Channel Configuration
The following example creates a BRI 0:0 interface for X.25 traffic over the D channel and then configures the new interface to carry X.25 traffic:
interface bri0isdn x25 dchannelisdn x25 static-tei 8!interface bri0:0ip address 10.1.1.2 255.255.255.0x25 address 31107000000100x25 htc 1x25 suppress-calling-addressx25 facility windowsize 2 2x25 facility packetsize 256 256x25 facility throughput 9600 9600x25 map ip 10.1.1.3 31107000000200Outbound Circuit-Switched X.25
The following example shows how to configure dynamic X.25 on an ISDN interface. Figure 23 illustrates the configuration.
Figure 23 Dynamic X.25 over ISDN
Configuration for Yen
version 12.0(5)Tservice timestamps debug uptimeservice timestamps log uptimeno service password-encryptionservice udp-small-serversservice tcp-small-servers!hostname yen!enable secret 5 $1$K32j$4AZW2oMDivpUeuMa/Fdcd.enable password secret!username mark password 0 ciscousername dinar password 0 ciscoip subnet-zerono ip domain-lookupip domain-name cicso.comip name-server 172.18.1.148!isdn switch-type basic-5essx25 routing!interface Loopback0no ip addressno ip directed-broadcastno ip mroute-cache!interface Ethernet0ip address 172.21.75.2 255.255.255.0no ip directed-broadcastno ip mroute-cachemedia-type 10BaseT!interface BRI1no ip addressno ip directed-broadcastno ip mroute-cachedialer pool-member 1isdn switch-type basic-5essno fair-queue!interface Dialer0ip address 2.1.1.1 255.0.0.0no ip directed-broadcastencapsulation x25no ip mroute-cachedialer remote-name dinardialer idle-timeout 180dialer string 81060dialer caller 81060dialer max-call 1dialer pool 1dialer-group 1x25 address 11111x25 map ip 2.1.1.2 22222!ip default-gateway 172.21.75.1no ip classlessip route 0.0.0.0 0.0.0.0 172.21.75.1no ip http server!access-list 101 permit ip any anydialer-list 1 protocol ip list 101!x25 route 22222 interface Dialer0x25 route 33333 interface Dialer0!line con 0exec-timeout 0 0transport input noneline aux 0transport input allline vty 0 4password ciscologinline vty 5 100password ciscologin!endConfiguration for Peso Acting as X.25 Switch
version 12.0(5)Tservice timestamps debug uptimeservice timestamps log uptimeno service password-encryption!hostname peso!enable secret 5 $1$.Q00$h3vIhbOwO1fPvA2LYx2gE.enable password cisco!ip subnet-zero!isdn switch-type primary-5essx25 routing!controller T1 0cablelength shortcablelength short 133!controller T1 1framing esfclock source line primarypri-group timeslots 1-24!controller T1 2cablelength shortcablelength short 133!controller T1 3cablelength shortcablelength short 133!interface Ethernet0ip address 172.21.75.3 255.255.255.0no ip directed-broadcast!interface Serial1:23no ip addressno ip directed-broadcastencapsulation pppdialer pool-member 1isdn switch-type primary-5essisdn incoming-voice modemno fair-queueno cdp enableppp authentication chap!interface Dialer0no ip addressno ip directed-broadcastencapsulation x25 dceno ip mroute-cachedialer remote-name yendialer idle-timeout 180dialer string 61401dialer caller 61401dialer max-call 1dialer pool 1x25 address 33333!interface Dialer1no ip addressno ip directed-broadcastencapsulation x25 dceno ip mroute-cachedialer remote-name dinardialer idle-timeout 180dialer string 61403dialer caller 61403dialer max-call 1dialer pool 1x25 address 44444!ip default-gateway 172.21.75.1no ip classlessip route 0.0.0.0 0.0.0.0 172.21.75.1no ip http server!x25 route 11111 interface Dialer0x25 route 22222 interface Dialer1x25 route source 11111 interface Dialer1x25 route input-interface Dialer0 interface Dialer1!line con 0transport input noneline 1 48line aux 0line vty 0 4password ciscologinline vty 5 100password ciscologin!endConfiguration for Dinar
version 12.0(5)Tservice timestamps debug uptimeservice timestamps log uptimeno service password-encryption!hostname dinar!logging buffered 16384 debuggingenable secret 5 $1$8EjF$4.S0AoMOVa5OIAYEMrrFI/enable password cisco!username yen password 0 ciscousername 7701username drachma password 0 ciscousername AODI password 0 ciscoip subnet-zeroip rcmd rcp-enableip rcmd rsh-enableip rcmd remote-username atirumal!isdn switch-type basic-5essx25 routing!controller T1 0/0!interface BRI3/1no ip addressno ip directed-broadcastno ip mroute-cachedialer pool-member 1isdn switch-type basic-5essno fair-queue!interface Dialer0ip address 2.1.1.2 255.0.0.0no ip directed-broadcastencapsulation x25no ip mroute-cachedialer remote-name yendialer idle-timeout 180dialer string 81060dialer caller 81060dialer max-call 1dialer pool 1dialer-group 1x25 address 22222x25 map ip 2.1.1.1 11111!interface Dialer1ip address 6.1.1.10 255.0.0.0no ip directed-broadcastno ip mroute-cachedialer in-banddialer-group 1no fair-queue!ip default-gateway 172.21.75.1no ip classlessip route 0.0.0.0 0.0.0.0 172.21.75.1no ip http server!access-list 101 permit ip any anydialer-list 1 protocol ip list 101!x25 route 11111 interface Dialer0x25 route 44444 interface Dialer0!
