MccownPennock850
Cisco CCNA / CCNP Exam Tutorial: Testing ISDN Links Without Pings
To earn your Cisco CCNA and CCNP certifications, you've got to master ISDN - and in spite of what some people say, there is still a lot of ISDN out there that requirements to be supported. read . And when it comes to troubleshooting ISDN, there is a lot to look at. Is the right ISDN switchtype configured? Are the dialer map statements appropriate? What about the dialer-group and dialer-list commands? And that's just the start.
I always say that all troubleshooting starts at Layer 1, the Physical layer of the OSI model. The usual approach of troubleshooting ISDN is sending pings across the link, but the connection can be tested without having using pings or even ahead of assigning IP addresses to the BRI interfaces!
It really is a very good thought to place these test calls just before 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 location a test contact without having making use of pings, use the isdn call interface command.Photography Brides of North Texas rent group policy manager .
R1#isdn contact interface bri0 8358662
R1#
03:54:43: BR0 DDR: Attempting to dial 8358662
03:54:43: %Link-3-UPDOWN: Interface BRI0:1, changed state to up
03:54:44: BR0:1 DDR: dialer protocol up
03:54:45: %LINEPROTO-5-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 call down appropriately, use isdn disconnect interface. IOS Help displays the possibilities with this command.
R1#isdn disconnect interface bri ?
all Disconnect the data call(s) on all b channels
b1 Disconnect the data call on b1 channel
b2 Disconnect the data get in touch with on b2 channel
R1#isdn disconnect interface bri all
03:58:36: BR0:1 DDR: disconnecting get in touch with
03:58:36: BR0:2 DDR: disconnecting get in touch with
03:58:36: %ISDN-6-DISCONNECT: Interface BRI0:1 disconnected from 8358662
R2, call lasted 20 seconds
03:58:36: %Hyperlink-3-UPDOWN: Interface BRI0:1, changed state to down
03:58:36: BR0:1 DDR: disconnecting get in touch with
03:58:37: %LINEPROTO-5-UPDOWN: Line protocol on Interface BRI0:1, changed state to down
I say "properly" due to the fact the one point you do not 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 significantly less. official site . Constantly let the d-channel do its function and tear the call down in an orderly fashion - don't 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
