ISND / DDR Call Status confusion

KPWrightKPWright Posts: 44Member ■■□□□□□□□□
Hi all,

I'm working on a lab in the Boson sim that deals with ISDN and legacy DDR. The lab has me set up an ISDN switched connection between two routers. I did, the pings work and things seem to be happy enough.

In looking at status, both bri0 interfaces are up/up, but both B channels for each of these interfaces are down/down since there is no active call. The lab then has you initiate a ping from one of the routers to the other using it's isdn interface address.

They then want you to check the status of the B channels and see that one of them is up with the reasoning that the ping has "established" a call. When I check isdn status, both B channels still show down/down.

I'm thinking this is probably what I should see since I wouldn't expect the connection to remain beyond what is necessary to satisfy the ping, but then I'm just guessing. Anyone care to weigh in on what you think should happen?

router1(config)# isdn switch-type basic-ni
router1(config)# dialer-list 1 protocol ip permit
router1(config)# username router2 password cisco
router1(config)# interface bri0
router1(config-if)# encapsulate ppp
router1(config-if)# ip address
router1(config-if)# isdn spid1 32177820010100
router1(config-if)# dialer-group 1
router1(config-if)# dialer map ip name router2 broadcast 7782001
router1(config-if)# ppp authentication chap
router1(config-if)# no shut

router2(config)# isdn switch-type basic-ni
router2(config)# dialer-list 1 protocol ip permit
router2(config)# username router1 password cisco
router2(config)# interface bri0
router2(config-if)# encapsulate ppp
router2(config-if)# ip address
router2(config-if)# isdn spid1 32177820020100
router2(config-if)# dialer-group 1
router2(config-if)# dialer map ip name router1 broadcast 7782002
router2(config-if)# ppp authentication chap
router2(config-if)# no shut

router1# ping [here the ping succeeds]
router1# show isdn status [still shows no active calls]
router1# show interfaces bri0 1 2 [both channels still down/down]icon_confused.gif:

Many thanks


  • captobviouscaptobvious Posts: 648Member
    First I'd check this (you'll need a login):

    640-802 CCNA® Exam Topics (Blueprint)

    to see if you find ISDN anywhere. Then I'd move on to the next lab.
  • KPWrightKPWright Posts: 44Member ■■□□□□□□□□
    Had the login, thanks for the link and the practical advice. Doesn't mention ISDN directly, I'd assume the content would fit under the WAN / PPP configuration topics if at all. The lab is defined in something titled "NETSIM FOR CCNA LAB MANUAL", but I'm tempted to **** it anyway (I'm thinkin' it's "broke").

    In the interim I cleaned house and re-loaded the starting lab configuration. This time after running through the configuration steps and showing isdn status for each router, both show the layer 1 status to be "Testing" instead of "Active" as they showed the first time. I found a brief reference in a Cisco doc to this as an "other" status that may show up in the output and indicated a "clear...." should remove it. It didn't.

    I'm moving on. Thanks for grounding me :D
  • captobviouscaptobvious Posts: 648Member
    No worries. Good luck on your studies! icon_thumright.gif
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