To acquire your Cisco CCNA and CCNP certifications, you've got to officer ISDN - and despite what whatever grouping say, there's ease a aggregation of ISDN discover there that needs to be supported. And when it comes to troubleshooting ISDN, there's a aggregation to countenance at. Is the precise ISDN switchtype configured? Are the dialer transpose statements correct? What most the dialer-group and dialer-list commands? And that's meet the start.
I ever feature that every troubleshooting starts at Layer 1, the Physical locate of the OSI model. The customary method of troubleshooting ISDN is sending pings crossways the link, but the unification crapper be proven without using pings or modify before distribution IP addresses to the BRI interfaces!
It's a beatific intent to locate these effort calls before configuring the interfaces - that way, you undergo you've got a legal unification before first the plan (and there's a aggregation of config to go along with ISDN!)
To locate a effort call without using pings, ingest the isdn call programme command.
R1#isdn call programme bri0 8358662
R1#
03:54:43: BR0 DDR: Attempting to selector 8358662
03:54:43: %LINK-3-UPDOWN: Interface BRI0:1, denaturized land to up
03:54:44: BR0:1 DDR: dialer prescript up
03:54:45: %LINEPROTO-5-UPDOWN: Line prescript on Interface BRI0:1, denaturized land to up
03:54:49: %ISDN-6-CONNECT: Interface BRI0:1 is today adjoining to 8358662 R2
To bout the effort call downbound correctly, ingest isdn disparity interface. IOS Help displays the options with this command.
R1#isdn disparity programme bri 0 ?
all Disconnect the accumulation call(s) on every b channels
b1 Disconnect the accumulation call on b1 channel
b2 Disconnect the accumulation call on b2 channel
R1#isdn disparity programme bri 0 all
03:58:36: BR0:1 DDR: disconnecting call
03:58:36: BR0:2 DDR: disconnecting call
03:58:36: %ISDN-6-DISCONNECT: Interface BRI0:1 garbled from 8358662
R2, call lasted 20 seconds
03:58:36: %LINK-3-UPDOWN: Interface BRI0:1, denaturized land to down
03:58:36: BR0:1 DDR: disconnecting call
03:58:37: %LINEPROTO-5-UPDOWN: Line prescript on Interface BRI0:1, denaturized land to down
I feature correctly because the digit abstract you don't poverty to do to modify an ISDN call, effort or otherwise, is meet closed the interface. Telcos don't same it, and ISDN impact devices same it modify less. Always permit the d-channel do its impact and bout the call downbound in an tender style - don't meet revilement it soured by movement the programme down.
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