Lab #11: ISDN Troubleshooting
Layer 3 debugging is turned on by issuing the debug isdn q931 command on the router. ISDN traffic consists of the call setup and teardown for each B channel that is either making a call or receiving a call
CHAP authentication progress and status is monitored by entering the debug ppp authen command.
Remember to also type the term mon command if you are not connected to the console port of the router.
Now that layer 3 debugging and PPP authentication debugging are enabled, let's place a call to RouterB by pinging IP address 196.1.1.2. Since Layer 3 debugging is turned on, we will see all of the call setup and
teardown. Since PPP authentication is turned on, we will see the progress of the CHAP authentication between RouterA and RouterB.
RouterA#ping 196.1.1.2
Type escape sequence to abort.
Sending 5, 100−byte ICMP Echos to 196.1.1.2, timeout is 2 seconds:
ISDN BR0/0: TX −> SETUP pd = 8 callref = 0x11 ← Call placed on B channel #1 Bearer Capability i = 0x8890
Channel ID i = 0x83
Keypad Facility i = '8995201'
ISDN BR0/0: RX <− CALL_PROC pd = 8 callref = 0x91 Channel ID i = 0x89
ISDN BR0/0: RX <− CONNECT pd = 8 callref = 0x91 ← Connect on B channel #1 Channel ID i = 0x89
%LINK−3−UPDOWN: Interface BRI0/0:1, changed state to up PPP BRI0/0:1: treating connection as a callout
ISDN BR0/0: TX −> CONNECT_ACK pd = 8 callref = 0x11
PPP BRI0/0:1: Send CHAP Challenge id=2 ← Chap challenge sent PPP BRI0/0:1: CHAP Challenge id=2 received from RouterB PPP BRI0/0:1: Send CHAP Response id=2
PPP BRI0/0:1: CHAP response received from RouterB PPP BRI0/0:1: CHAP Response id=2 received from RouterB
PPP BRI0/0:1: Send CHAP Success id=2 ← CHAP success B channel #1 PPP BRI0/0:1: remote passed CHAP authentication
PPP BRI0/0:1: Passed CHAP authentication with remote
%LINK−3−UPDOWN: Interface Virtual−Access1, changed state to up PPP Virtual−Access1: treating connection as a callin
%LINEPROTO−5−UPDOWN: Line protocol on Interface BRI0/0:1, changed state to up
%LINEPROTO−5−UPDOWN: Line protocol on Interface Virtual−Access1, changed state to up ISDN BR0/0: TX −> SETUP pd = 8 callref = 0x12 ← Call placed on B channel #2
Bearer Capability i = 0x8890 Channel ID i = 0x83
Keypad Facility i = '8995201'
ISDN BR0/0: RX <− CALL_PROC pd = 8 callref = 0x92 Channel ID i = 0x8A
ISDN BR0/0: Event: incoming ces value = 2
ISDN BR0/0: RX <− CONNECT pd = 8 callref = 0x92 ← Connect on B channel #2 Channel ID i = 0x8A
ISDN BR0/0: Event: incoming ces value = 2
%LINK−3−UPDOWN: Interface BRI0/0:2, changed state to up PPP BRI0/0:2: treating connection as a callout
ISDN BR0/0: TX −> CONNECT_ACK pd = 8 callref = 0x12
PPP BRI0/0:2: Send CHAP Challenge id=2 ← Chap challenge sent PPP BRI0/0:2: CHAP Challenge id=2 received from RouterB PPP BRI0/0:2: Send CHAP Response id=2
PPP BRI0/0:2: CHAP response received from RouterB PPP BRI0/0:2: CHAP Response id=2 received from RouterB
PPP BRI0/0:2: Send CHAP Success id=2 ← CHAP success B channel #2 PPP BRI0/0:2: remote passed CHAP authentication.
PPP BRI0/0:2: Passed CHAP authentication with remote.
%LINEPROTO−5−UPDOWN: Line protocol on Interface BRI0/0:2, changed state to up
%ISDN−6−CONNECT: Interface BRI0/0:2 is now connected to 8995201 RouterB
..!!!
Success rate is 60 percent (3/5), round−trip min/avg/max = 20/22/24 ms RouterA#
The ping was only 60−percent successful because it was started while the router was still making its ISDN call and connecting.
The show ppp multilink command is used to display the status of any multilink PPP bundles on the router.
We see from the output below that we have two B channels that are connected into a multilink bundle on RouterA.
RouterA#show ppp multilink
Bundle RouterB, 2 members, Master link is Virtual−Access1 Dialer Interface is BRI0/0
0 lost fragments, 0 reordered, 0 unassigned, sequence 0x6/0x8 rcvd/sent 0 discarded, 0 lost received, 1/255 load
Member Links: 2 ← 2 B channels in a multilink bundle BRI0/0:1
BRI0/0:2
We see that when a call is active on the BRI interface, the D channel still showsup/up (spoofing).
RouterA#show interface bri 0/0
BRI0/0 is up, line protocol is up (spoofing) ← D channel will show up / up (spoofing) whether or not a call is connected
Hardware is QUICC BRI with U interface Internet address is 196.1.1.1/24
MTU 1500 bytes, BW 64 Kbit, DLY 20000 usec, rely 255/255, load 1/255 Encapsulation PPP, loopback not set
Last input 00:00:03, output never, output hang never Last clearing of "show interface" counters never Queueing strategy: fifo
Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec 168 packets input, 1022 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 168 packets output, 1152 bytes, 0 underruns
0 output errors, 0 collisions, 4 interface resets 0 output buffer failures, 0 output buffers swapped out 1 carrier transitions
We see that both B channels are now in an up/up state since we have an active call on both channels of the BRI.
RouterA#show interface bri 0/0:1
BRI0/0:1 is up, line protocol is up ← B channel #1 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, keepalive set (10 sec)
LCP Open, multilink Open
Last input 00:00:03, output 00:00:03, output hang never Last clearing of "show interface" counters never
Queueing strategy: fifo
Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec 55 packets input, 1292 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 56 packets output, 1702 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets 0 output buffer failures, 0 output buffers swapped out 17 carrier transitions
RouterA#show interface bri 0/0:2
BRI0/0:2 is up, line protocol is up ← B channel #2 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, keepalive set (10 sec)
LCP Open, multilink Open
Last input 00:00:00, output 00:00:00, output hang never Last clearing of "show interface" counters never
Queueing strategy: fifo
Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec 42 packets input, 1116 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 45 packets output, 1554 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets 0 output buffer failures, 0 output buffers swapped out 3 carrier transitions
The output of the show dialer command will give you important information on how many successful calls and how many failed calls have been made. The command output will also show what phone number is being dialed to place calls. Under each B channel you will also see information on how long the call has been connected, the time until the call is disconnected, what number the call actually connected to, and the reason that the call was made.
RouterA#show dialer
BRI0/0 − dialer type = ISDN
Dial String Successes Failures Last called Last status 8995201 4 14 00:00:25 successful 0 incoming call(s) have been screened.
BRI0/0:1 − dialer type = ISDN
Idle timer (90 secs), Fast idle timer (20 secs) Wait for carrier (30 secs), Re−enable (15 secs) Dialer state is physical layer up
Dial reason: ip (s5196.1.1.1, d5196.1.1.2) ← Reason for call Time until disconnect 60 secs ← Time until disconnect
Current call connected 00:00:26 ← Current connect time Connected to 8995201 (RouterB)← Number connected
BRI0/0:2 − dialer type = ISDN
Idle timer (90 secs), Fast idle timer (20 secs) Wait for carrier (30 secs), Re−enable (15 secs) Dialer state is physical layer up
Dial reason: Multilink bundle overloaded Time until disconnect 62 secs
Current call connected 00:00:27 Connected to 8995201 (RouterB)
The show dialer map command is another important tool for troubleshooting layer 3 connectivity. This command will display all static and dynamic dialer map statements. We see that we have a static map defined on RouterA that tells us what number to call to get to RouterB at IP address 196.1.1.2.
RouterA#show dialer map
Static dialer map ip 196.1.1.2 name RouterB broadcast (8995201) on BRI0/0
The following screen print shows what will be output from the router when the router disconnects an ISDN call. ISDN Q931 debugging is enabled on this trace. You can tell that the router is sending the Disconnect message to the ISDN switch because the output message indicates TX −> DISCONNECT, which tells us that the router is transmitting a disconnect message to the ISDN switch.
%LINEPROTO−5−UPDOWN: Line protocol on Interface Virtual−Access1, changed state to down
%LINK−3−UPDOWN: Interface Virtual−Access1, changed state to down
%ISDN−6−DISCONNECT: Interface BRI0/0:1 disconnected from 8995201 RouterB, call lasted 94 seconds
%ISDN−6−DISCONNECT: Interface BRI0/0:2 disconnected from 8995201 RouterB, call lasted 91 seconds
ISDN BR0/0: TX −> DISCONNECT pd = 8 callref = 0x11 ← Disconnect B channel #1
Cause i = 0x8090 − Normal call clearing
ISDN BR0/0: TX −> DISCONNECT pd = 8 callref = 0x12 ← Disconnect B channel #2 Cause i = 0x8090 − Normal call clearing
ISDN BR0/0: RX <− RELEASE pd = 8 callref = 0x91
%LINK−3−UPDOWN: Interface BRI0/0:1, changed state to down ISDN BR0/0: TX −> RELEASE_COMP pd = 8 callref = 0x11 ISDN BR0/0: RX <− RELEASE pd = 8 callref = 0x92 ISDN BR0/0: Event: incoming ces value = 2
%LINK−3−UPDOWN: Interface BRI0/0:2, changed state to down ISDN BR0/0: TX −> RELEASE_COMP pd = 8 callref = 0x12
%LINEPROTO−5−UPDOWN: Line protocol on Interface BRI0/0:1, changed state to down
%LINEPROTO−5−UPDOWN: Line protocol on Interface BRI0/0:2, changed state to down
CHAP Failure
Let's force a CHAP authentication failure on our test network and see how to debug this problem. We see from our configuration that configuring CHAP involves two main steps:
You need the command PPP authentication chap under the appropriate router interface.
1.
You need a username that corresponds to the far−end router's hostname as well as a password that matches the password set on the far−end router's username statement.
2.
Our current configuration for RouterA has the statement username RouterB password 7 070C285F4D06.
The password is encrypted and is not visible in its clear text, but it was set to cisco when the configuration was first created.
Enter configuration mode by typing config term at the command prompt. Enter the command username RouterB password 0 disco. The corresponding username statement on RouterB contains the password cisco.
Having a different CHAP password on RouterA and on RouterB will create a CHAP authentication failure when the two routers attempt to authenticate with each other.
RouterA#config term
Enter configuration commands, one per line. End with CNTL/Z.
RouterA(config)#username RouterB password 0 disco RouterA(config)#exit
RouterA#
Make sure that PPP authentication debugging is enabled by typing the debug ppp authen command.
RouterA#debug ppp authen
PPP authentication debugging is on
Now let's bring up the ISDN circuit by starting a ping from RouterA to RouterB at IP address 196.1.1.2.
Notice in the debug output that RouterA declares a CHAP failure when it is trying to authenticate with RouterB. This example demonstrates that it is crucial to enable PPP authentication debugging when having a problem establishing an ISDN call.
RouterA#ping 196.1.1.2
Type escape sequence to abort.
Sending 5, 100−byte ICMP Echos to 196.1.1.2, timeout is 2 seconds:
%LINK−3−UPDOWN: Interface BRI0/0:1, changed state to up PPP BRI0/0:1: treating connection as a callout
PPP BRI0/0:1: Send CHAP Challenge id=3 ← Chap sent on B channel #1 PPP BRI0/0:1: CHAP Challenge id=3 received from RouterB
PPP BRI0/0:1: Send CHAP Response id=3
PPP BRI0/0:1: CHAP response received from RouterB PPP BRI0/0:1: CHAP Response id=3 received from RouterB
PPP BRI0/0:1: Send CHAP Failure id=3, MD compare failed ← CHAP failure on B channel #1
%LINK−3−UPDOWN: Interface BRI0/0:1, changed state to down.
%LINK−3−UPDOWN: Interface BRI0/0:1, changed state to up PPP BRI0/0:1: treating connection as a callout
PPP BRI0/0:1: Send CHAP Challenge id=4 ← Chap sent on B channel #1 PPP BRI0/0:1: CHAP Challenge id=4 received from RouterB
PPP BRI0/0:1: Send CHAP Response id=4
PPP BRI0/0:1: CHAP response received from RouterB PPP BRI0/0:1: CHAP Response id=4 received from RouterB
PPP BRI0/0:1: Send CHAP Failure id=4, MD compare failed ← CHAP failure on B channel #1
%LINK−3−UPDOWN: Interface BRI0/0:1, changed state to down.
%LINK−3−UPDOWN: Interface BRI0/0:1, changed state to up PPP BRI0/0:1: treating connection as a callout
PPP BRI0/0:1: Send CHAP Challenge id=5 ← The far end router tries to CHAP several more times and then disconnects the call
PPP BRI0/0:1: CHAP Challenge id=5 received from RouterB PPP BRI0/0:1: Send CHAP Response id=5
PPP BRI0/0:1: CHAP response received from RouterB PPP BRI0/0:1: CHAP Response id=5 received from RouterB PPP BRI0/0:1: Send CHAP Failure id=5, MD compare failed
%LINK−3−UPDOWN: Interface BRI0/0:1, changed state to down.
%LINK−3−UPDOWN: Interface BRI0/0:1, changed state to up PPP BRI0/0:1: treating connection as a callout
PPP BRI0/0:1: Send CHAP Challenge id=6
PPP BRI0/0:1: CHAP Challenge id=6 received from RouterB PPP BRI0/0:1: Send CHAP Response id=6
PPP BRI0/0:1: CHAP response received from RouterB PPP BRI0/0:1: CHAP Response id=6 received from RouterB PPP BRI0/0:1: Send CHAP Failure id=6, MD compare failed
%LINK−3−UPDOWN: Interface BRI0/0:1, changed state to down
%LINK−3−UPDOWN: Interface BRI0/0:1, changed state to up PPP BRI0/0:1: treating connection as a callout
PPP BRI0/0:1: Send CHAP Challenge id=7
PPP BRI0/0:1: CHAP Challenge id=7 received from RouterB PPP BRI0/0:1: Send CHAP Response id=7
PPP BRI0/0:1: CHAP response received from RouterB PPP BRI0/0:1: CHAP Response id=7 received from RouterB PPP BRI0/0:1: Send CHAP Failure id=7, MD compare failed
%LINK−3−UPDOWN: Interface BRI0/0:1, changed state to down ← Call gets disconnected Success rate is 0 percent (0/5)
Now let's change the CHAP password back to its correct value on RouterA. Enter configuration mode and type the proper username command as shown:
RouterA#config term
Enter configuration commands, one per line. End with CNTL/Z.
RouterA(config)#username RouterB password 0 cisco ← Correct password RouterA(config)#exit
RouterA#
Now let's verify that we can make a call and pass CHAP authentication. Ping RouterB at IP address 196.1.1.2.
RouterA#ping 196.1.1.2
Type escape sequence to abort.
Sending 5, 100−byte ICMP Echos to 196.1.1.2, timeout is 2 seconds:
%LINK−3−UPDOWN: Interface BRI0/0:1, changed state to up
%LINK−3−UPDOWN: Interface Virtual−Access1, changed state to up
%LINEPROTO−5−UPDOWN: Line protocol on Interface BRI0/0:1, changed state to up
%LINEPROTO−5−UPDOWN: Line protocol on Interface Virtual−Access1, changed state to up
%LINK−3−UPDOWN: Interface BRI0/0:2, changed state to up
%LINEPROTO−5−UPDOWN: Line protocol on Interface BRI0/0:2, changed state to up
%ISDN−6−CONNECT: Interface BRI0/0:2 is now connected to 8995201 RouterB .!!!!
Success rate is 80 percent (4/5), round−trip min/avg/max = 32/33/36 ms
Wrong Dial Number
Now let's see how to debug the situation where you are dialing the wrong number. Recall from the portion of RouterA's configuration shown below that RouterA dials the number 8995201 to call RouterB.
RouterA#show run
Building configuration . . .
interface BRI0/0
ip address 196.1.1.1 255.255.255.0 encapsulation ppp
isdn spid1 5101 8995101 isdn spid2 5102 8995102 dialer idle−timeout 90
dialer map ip 196.1.1.2 name RouterB broadcast 8995201 ← Dial 8995201 to call RouterB dialer load−threshold 1
dialer−group 1 no fair−queue
ppp authentication chap ppp multilink
Let's change the dial number in RouterA's configuration. Enter configuration mode and delete the current dialer map and add a new dialer map that calls 8996000 instead of the correct number 8995201.
RouterA#config term
Enter configuration commands, one per line. End with CNTL/Z.
RouterA(config)#interface bri 0/0
RouterA(config−if)#no dialer map ip 196.1.1.2 name RouterB broadcast 8995201 RouterA(config−if)#dialer map ip 196.1.1.2 name RouterB broadcast 8996000 RouterA(config−if)#exit á
RouterA(config)#exit Incorrect number RouterA#
Now turn on ISDN layer 3 call control debugging with the debug isdn q931 command.
RouterA#debug isdn q931
ISDN Q931 packets debugging is on
Now let's ping RouterB at IP address 196.1.1.2. Remember that we will be dialing the wrong number to get to RouterB. Our Adtran Atlas 800 ISDN switch is not provisioned with 8996000 as a valid number.
RouterA#ping 196.1.1.2
Type escape sequence to abort.
Sending 5, 100−byte ICMP Echos to 196.1.1.2, timeout is 2 seconds:
ISDN BR0/0: TX −> SETUP pd = 8 callref = 0x1A Bearer Capability i = 0x8890
Channel ID i = 0x83
Keypad Facility i = '8996000' ← RouterA is dialing 8996000
ISDN BR0/0: RX <− CALL_PROC pd = 8 callref = 0x9A Channel ID i = 0x89
ISDN BR0/0: RX <− DISCONNECT pd = 8 callref = 0x9A
Cause i = 0x8281 − Unallocated/unassigned number ← The ISDN switch sends an immediate disconnect message to RouterA. The cause code indicates that we are dialing an unassigned
number.
ISDN BR0/0: TX −> RELEASE pd = 8 callref = 0x1A ISDN BR0/0: RX <− RELEASE_COMP pd = 8 callref = 0x9A.
ISDN BR0/0: TX −> SETUP pd = 8 callref = 0x1B ← Router dialed again Bearer Capability i = 0x8890
Channel ID i = 0x83
Keypad Facility i = '8996000'
ISDN BR0/0: RX <− CALL_PROC pd = 8 callref = 0x9B Channel ID i = 0x89
ISDN BR0/0: RX <− DISCONNECT pd = 8 callref = 0x9B Cause i = 0x8281 − Unallocated/unassigned number ISDN BR0/0: TX −> RELEASE pd = 8 callref = 0x1B ISDN BR0/0: RX <− RELEASE_COMP pd = 8 callref = 0x9B.
ISDN BR0/0: TX −> SETUP pd = 8 callref = 0x1C Bearer Capability i = 0x8890
Channel ID i = 0x83
Keypad Facility i = '8996000'
ISDN BR0/0: RX <− CALL_PROC pd = 8 callref = 0x9C Channel ID i = 0x89
ISDN BR0/0: RX <− DISCONNECT pd = 8 callref = 0x9C Cause i = 0x8281 − Unallocated/unassigned number ISDN BR0/0: TX −> RELEASE pd = 8 callref = 0x1C
ISDN BR0/0: RX <− RELEASE_COMP pd = 8 callref = 0x9C.
ISDN BR0/0: TX −> SETUP pd = 8 callref = 0x1D Bearer Capability i = 0x8890
Channel ID i = 0x83
Keypad Facility i = '8996000'
ISDN BR0/0: RX <− CALL_PROC pd = 8 callref = 0x9D Channel ID i = 0x89
ISDN BR0/0: RX <− DISCONNECT pd = 8 callref = 0x9D Cause i = 0x8281 − Unallocated/unassigned number ISDN BR0/0: TX −> RELEASE pd = 8 callref = 0x1D
ISDN BR0/0: RX <− RELEASE_COMP pd = 8 callref = 0x9D.
ISDN BR0/0: TX −> SETUP pd = 8 callref = 0x1E ← The router dials a total of 5 times before giving up
Bearer Capability i = 0x8890 Channel ID i = 0x83
Keypad Facility i = '8996000'
ISDN BR0/0: RX <− CALL_PROC pd = 8 callref = 0x9E Channel ID i = 0x89
ISDN BR0/0: RX <− DISCONNECT pd = 8 callref = 0x9E Cause i = 0x8281 − Unallocated/unassigned number ISDN BR0/0: TX −> RELEASE pd = 8 callref = 0x1E
ISDN BR0/0: RX <− RELEASE_COMP pd = 8 callref = 0x9E.
Success rate is 0 percent (0/5)
Now let's change the dialer map for RouterA back to the correct dial number. Enter configuration mode, delete the current incorrect dialer map, and add back the correct dial map.
RouterA#config term
Enter configuration commands, one per line. End with CNTL/Z.
RouterA(config)#interface bri 0/0
RouterA(config−if)#no dialer map ip 196.1.1.2 name RouterB broadcast 8996000 RouterA(config−if)#dialer map ip 196.1.1.2 name RouterB broadcast 8995201 RouterA(config−if)#exit
RouterA(config)#exit RouterA#
A ping to RouterB at IP address 196.1.1.2 will now be successful. Notice from the layer 3 trace below that RouterA is now dialing the correct number, 8995201.
RouterA#ping 196.1.1.2
Type escape sequence to abort.
Sending 5, 100−byte ICMP Echos to 196.1.1.2, timeout is 2 seconds:
ISDN BR0/0: TX −> SETUP pd = 8 callref = 0x1F
%LINK−3−UPDOWN: Interface BRI0/0:1, changed state to up ISDN BR0/0: TX −> CONNECT_ACK pd = 8 callref = 0x1F
%LINK−3−UPDOWN: Interface Virtual−Access1, changed state to up
%LINEPROTO−5−UPDOWN: Line protocol on Interface BRI0/0:1, changed state to up
%LINEPROTO−5−UPDOWN: Line protocol on Interface Virtual−Access1, changed state to up ISDN BR0/0: TX −> SETUP pd = 8 callref = 0x20
ISDN BR0/0: Event: incoming ces value = 2
ISDN BR0/0: RX <− CONNECT pd = 8 callref = 0xA0 Channel ID i = 0x8A
ISDN BR0/0: Event: incoming ces value = 2
%LINK−3−UPDOWN: Interface BRI0/0:2, changed state to up ISDN BR0/0: TX −> CONNECT_ACK pd = 8 callref = 0x20
%LINEPROTO−5−UPDOWN: Line protocol on Interface BRI0/0:2, changed state to up
%ISDN−6−CONNECT: Interface BRI0/0:2 is now connected to 8995201 RouterB
.!!!!
Success rate is 80 percent (4/5), round−trip min/avg/max = 32/33/36 ms
Incoming Call Trace
Now let's look at what an incoming call looks like. Unlike an outgoing call, we see that the Setup message is received by the router. We also see that the router displays the number of the calling party. Notice that the first incoming call comes from 8995101 and the second incoming call comes from 8995102.
*Mar 1 00:55:48: ISDN BR0/0: RX <− SETUP pd = 8 callref = 0x0E
*Mar 1 00:55:48: Bearer Capability i = 0x8890
*Mar 1 00:55:48: Channel ID i = 0x89
*Mar 1 00:55:48: Calling Party Number i = '!', 0x80, '0008995101'
*Mar 1 00:55:48: Called Party Number i = 0xC1, '8995201'
%LINK−3−UPDOWN: Interface BRI0/0:1, changed state to up
*Mar 1 00:55:48: ISDN BR0/0: TX −> CONNECT pd = 8 callref = 0x8E
*Mar 1 00:55:48: Channel ID i = 0x89
*Mar 1 00:55:48: ISDN BR0/0: RX <− CONNECT_ACK pd = 8 callref = 0x0E
*Mar 1 00:55:48: PPP BRI0/0:1: Send CHAP challenge id=10 to remote
*Mar 1 00:55:48: PPP BRI0/0:1: CHAP challenge from RouterA
*Mar 1 00:55:48: PPP BRI0/0:1: CHAP response received from RouterA
*Mar 1 00:55:48: PPP BRI0/0:1: CHAP response id=10 received from RouterA
*Mar 1 00:55:48: PPP BRI0/0:1: Send CHAP success id=10 to remote
*Mar 1 00:55:48: PPP BRI0/0:1: remote passed CHAP authentication.
*Mar 1 00:55:48: PPP BRI0/0:1: remote passed CHAP authentication.