AshelyFournier945
To earn your Cisco CCNA and CCNP certifications, you've got to master ISDN - and despite what some folks say, there's nevertheless a lot of ISDN out there that demands to be supported. And when it comes to troubleshooting ISDN, there is a lot to look at. Is the appropriate ISDN switchtype configured? Are the dialer map statements appropriate? What about the dialer-group and dialer-list commands? And that is just the start off.
I usually say that all troubleshooting starts at Layer 1, the Physical layer of the OSI model. The usual strategy of troubleshooting ISDN is sending pings across the hyperlink, but the connection can be tested without having using pings or even ahead of assigning IP addresses to the BRI interfaces!
It is a great notion to spot these test calls ahead of configuring the interfaces - that way, you know you have got a valid connection prior to starting the configuration (and there's a lot of config to go along with ISDN!)
To place a test get in touch with with out employing pings, use the isdn get in touch with interface command.
R1#isdn call interface bri0 8358662
R1#
03:54:43: BR0 DDR: Attempting to dial 8358662
03:54:43: %Hyperlink-3-UPDOWN: Interface BRI0:1, changed state to up
03:54:44: BR0:1 DDR: dialer protocol up
03:54:45: %LINEPROTO-five-UPDOWN: Line protocol on Interface BRI0:1, changed state to up
03:54:49: %ISDN-six-CONNECT: Interface BRI0:1 is now connected to 8358662 R2
To tear the test get in touch with down correctly, use isdn disconnect interface. IOS Help displays the choices with this command.
R1#isdn disconnect interface bri ?
all Disconnect the information get in touch with(s) on all b channels
b1 Disconnect the information get in touch with on b1 channel
b2 Disconnect the data contact on b2 channel
R1#isdn disconnect interface bri all
03:58:36: BR0:1 DDR: disconnecting get in touch with
03:58:36: BR0:two DDR: disconnecting call
03:58:36: %ISDN-six-DISCONNECT: Interface BRI0:1 disconnected from 8358662
R2, get in touch with lasted 20 seconds
03:58:36: %Hyperlink-three-UPDOWN: Interface BRI0:1, changed state to down
03:58:36: BR0:1 DDR: disconnecting contact
03:58:37: %LINEPROTO-5-UPDOWN: Line protocol on Interface BRI0:1, changed state to down
I say "appropriately" simply because the a single factor you don't want to do to end an ISDN call, test or otherwise, is just shut the interface. Telcos do not like it, and ISDN lab devices like it even much less. Always let the d-channel do its function and tear the call down in an orderly style - never just reduce it off by shutting the interface down.SDM Software, Inc. 2100 4th St, #132 San Rafael, CA 94901 (415) 670-9302 http://sdmsoftware.com inside microsoft group policy
