This document discusses configuration of PPP, ISDN, and Frame Relay. It describes how to configure PPP authentication using CHAP. For ISDN, it explains the reference points and covers configuring both BRI and PRI interfaces, including setting switch types, SPIDs, dial parameters and pools. For Frame Relay, it outlines configuring the encapsulation, LMI type, DLCI mapping with or without inverse ARP, and use of subinterfaces.

1. PPP, ISDN, & Frame Relay
Chapters 11-12
Networking Essentials – Eric Vanderburg © 2005

2. PPP

Interface serial 0
Encapsulation ppp
 Ppp authentication chap

Username CNT password class
 Authentication will succeed if the
password is the same on both ends.

Networking Essentials – Eric Vanderburg © 2005

3. Functions & Reference Points

U reference point always connects to the
ISP on one end

Other end is connected to NT1/TE1 on the
router or NT1 device
 NT1
device uses reference pt S/T to connect to
the router TE1
 NT1 device uses reference pt T to connect to
NT2, NT2 uses S reference pt to connect to the
router TE1. (NT2 is often used with a PBX CPE)
 NT1 device using reference pt S/T connects to
TA, TA uses R reference pt to connect to TE2
Networking Essentials – Eric Vanderburg © 2005

4. ISDN Configuration (BRI)
Isdn switch-type basic-ni1
 Switch types

Basic-Dms100, Basic-ni1, & basic-5ess
(North America)
 Basic-net3 (Europe & UK)
 NTT (Japan)
 Vn3 (France)
 1tr6 (Germany)
 Ts013 (Australia)

Networking Essentials – Eric Vanderburg © 2005

5. ISDN Configuration

Interface bri 0







Isdn spid1 83940293774856
Isdn spid2 93849380964893
Dialer idle-timeout 300 (disconnect after 300)
Dial wait-for-carrier time 20 (wait 20 secs for
response from ISP)
Dialer fast-idle 120
Ppp multilink
Dialer load-threshold 50 either (dial another line if
using 50% capacity)
Networking Essentials – Eric Vanderburg © 2005

6. ISDN Configuration
Dialer-list 1 protocol ip list 101
 Interface bri 0

Dialer-string 14405551212 (always dial this
number)
 Dialer map ip 172.16.2.1 broadcast name
LA 14045967491
 Dialer-group 1

Networking Essentials – Eric Vanderburg © 2005

7. ISDN Configuration (PRI)

Controller t1 1/0

Framing esf (how to interpret frames)
 Sf,

esf, or crc4
Linecode b8zs (encoding – what is 0 &1)
 Ami,


b8zs, or hdb3
Pri-group timeslots 1-24
Interface serial 1/0:23 (last subinterface
representing the D channel)

Configuration similar to BRI
Networking Essentials – Eric Vanderburg © 2005

8. ISDN Configuration
Create an interface for each remote site
 Interface dialer 1

Ip address…
 Encapsulation ppp
 Ppp authentication chap
 Dialer remote-name LA
 Dialer string 172.16.2.1 14045967491
 Dialer-group 1 (defines interesting traffic)
 Dialer pool 3 (BRI lines can be in this)

Networking Essentials – Eric Vanderburg © 2005

9. ISDN Configuration

Interface serial 1/0:0
Encapsulation ppp
 Ppp authentication chap
 Isdn spid 555094830928394
 Dialer pool-member 3

Networking Essentials – Eric Vanderburg © 2005

10. Frame Relay

Interface serial 0
Encapsulation frame-relay
 Frame-relay lmi type ansi (router to switch)

 Ansi,

q933a, or Cisco (Cisco is default)
Frame-relay interface-dlci 50 ietf
 Optional
ietf/cisco (cisco is default. Set to ietf if
using another brand of router)
Networking Essentials – Eric Vanderburg © 2005

11. Frame Relay
If you are not using inverse arp
 Interface serial 0

No frame-relay inverse-arp
 Frame-relay map ip 192.168.0.2 51
broadcast
 (broadcast allows broadcasted routing
updates to be sent unicast to each mapped
router)


Show frame-relay map
Networking Essentials – Eric Vanderburg © 2005

12. Frame Relay


Subinterfaces
Interface serial 0.1 point-to-point



Interface serial 0


Ip address…
Frame-relay interface-dlci 51
Encapsulation frame-relay
Interface serial 0.1 multipoint



ip address…
Frame-relay interface-dlci 51
Frame-relay interface-dlci 52
Networking Essentials – Eric Vanderburg © 2005