! enable password cisco ! username RouterB password 070C285F4D06 isdn switch−type basic−ni1 ← Set D channel call control ! interface BRI0/0 no ip address encapsulation ppp isdn spid1 5101 8995101 ← Set SPIDs for both B channels isdn spid2 5102 8995102 dialer pool−member ← This interface will be part of dialer pool #1 no fair−queue ppp authentication chap ppp multilink ← Request a PPP multilink session ! interface Dialer0 ip address 196.1.1.1 255.255.255.0 encapsulation ppp dialer remote−name RouterB ← Hostname of far end router dialer idle−timeout 90 ← Disconnect the call 90 seconds after the last interesting packet is received dialer string 8995201 ← Define number to dial to reach far end dialer load−threshold ← Define threshold for adding additional B channels dialer pool ← This is dialer pool #1 dialer−group ← Associate this interface with dialer−list ! no ip classless ip route 196.1.1.2 255.255.255.255 Dialer0 dialer−list protocol ip permit ← Define interesting traffic ! line password cisco login line aux line vty password cisco login ! end RouterB RouterB#show run Building configuration Current configuration: ! version 11.2 service timestamps debug datetime localtime no service udp−small−servers no service tcp−small−servers ! hostname RouterB ! enable password cisco ! username RouterA password 094F471A1A0A isdn switch−type basic−ni1 ← Set the D channel call control ! interface Serial0/0 ip address 193.1.1.2 255.255.255.0 encapsulation ppp ! interface BRI0/0 ip address 196.1.1.2 255.255.255.0 encapsulation ppp 62 isdn spid1 5201 8995201 ← Set the SPID for both B channels isdn spid2 5202 8995202 dialer idle−timeout 90 ← Define the interesting traffic timeout dialer map ip 196.1.1.1 name RouterA ← Define a next hop address dialer−group ← Associate the interface with dialer−list no fair−queue ppp authentication chap ppp multilink ! no ip classless dialer−list protocol ip permit ← Define interesting traffic ! line line aux line vty password cisco login ! end Monitoring and Testing the Configuration Let's start by connecting to RouterB and verifying that the ISDN circuit is up and active Type the show isdn status command to view the status of the BRI circuit on RouterB We see that the SPID for both B channels has been sent to the ISDN switch and is valid RouterB#show isdn status The current ISDN Switchtype = basic−ni1 ISDN BRI0/0 interface Layer Status: ACTIVE Layer Status: TEI = 64, State = MULTIPLE_FRAME_ESTABLISHED TEI = 65, State = MULTIPLE_FRAME_ESTABLISHED Spid Status: TEI 64, ces = 1, state = 5(init) spid1 configured, spid1 sent, spid1 valid ← B channel #1 Endpoint ID Info: epsf = 0, usid = 70, tid = TEI 65, ces = 2, state = 5(init) spid2 configured, spid2 sent, spid2 valid ← B channel #2 Endpoint ID Info: epsf = 0, usid = 70, tid = Layer Status: Active Layer Call(s) Activated dsl CCBs = CCB:callid=0, callref=0, sapi=0, ces=1, B−chan=0 Number of active calls = Number of available B−channels = Total Allocated ISDN CCBs = Let's verify the status of the bri interface and make sure that the D channel is active between RouterB and the ISDN switch Type show interface bri 0/0 to view the status of the D channel The up/up (spoofing) state indicates that the D channel is up and active RouterB#show interface bri 0/0 BRI0/0 is up, line protocol is up (spoofing) ← Active D channel Hardware is QUICC BRI with U interface Internet address is 196.1.1.2/24 MTU 1500 bytes, BW 64 Kbit, DLY 20000 usec, rely 255/255, load 1/255 Encapsulation PPP, loopback not set Now let's connect to RouterA and verify that the BRI interface is ready to place a call Type the show isdn status command to view the status of the BRI interface We see that a SPID for B channel #1 and B channel 63 #2 has been successfully sent to the switch RouterA#show isdn status The current ISDN Switchtype = basic−ni1 ISDN BRI0/0 interface Layer Status: ACTIVE Layer Status: TEI = 64, State = MULTIPLE_FRAME_ESTABLISHED TEI = 65, State = MULTIPLE_FRAME_ESTABLISHED Spid Status: TEI 64, ces = 1, state = 8(established) spid1 configured, spid1 sent, spid1 valid ← B channel #1 Endpoint ID Info: epsf = 0, usid = 70, tid = TEI 65, ces = 2, state = 8(established) spid2 configured, spid2 sent, spid2 valid ← B channel #2 Endpoint ID Info: epsf = 0, usid = 70, tid = Layer Status: Active Layer Call(s) Activated dsl CCBs = Total Allocated ISDN CCBs = Let's verify that the D channel for the BRI interface on RouterA is active Type the show interface bri 0/0 command to view the D channel The up/up (spoofing) state of the interface indicates that the D channel between RouterA and the ISDN switch is active RouterA#show interface bri 0/0 BRI0/0 is up, line protocol is up (spoofing) ← Active D channel Hardware is QUICC BRI with U interface MTU 1500 bytes, BW 64 Kbit, DLY 20000 usec, rely 255/255, load 1/255 Encapsulation PPP, loopback not set Let's turn on PPP authentication and ISDN call control debugging with the debug ppp authen command and the debug isdn q931 commands Active debug commands can be displayed with the show debug command Remember that you also need to type the term mon command if you are not connected to the router's console port RouterA#show debug PPP: PPP authentication debugging is on ISDN: ISDN Q931 packets debugging is on Dial on demand: Dial on demand events debugging is on Let's ping the BRI interface on RouterB at IP address 196.1.1.2 Notice that this ping will activate the BRI interface RouterA#ping 196.1.1.2 Type escape sequence to abort Sending 5, 100−byte ICMP Echos to 196.1.1.2, timeout is seconds: BRI0/0: Dialing cause ip (s=196.1.1.1, d=196.1.1.2) BRI0/0: Attempting to dial 8995201 ISDN BR0/0: TX −> SETUP pd = callref = 0x0B ← Placing call on B channel #1 Bearer Capability i = 0x8890 Channel ID i = 0x83 Keypad Facility i = '8995201' ISDN BR0/0: RX SETUP pd = callref = 0x0C ← Placing call on B channel #2 Bearer Capability i = 0x8890 Channel ID i = 0x83 Keypad Facility i = '8995201' ISDN BR0/0: RX