Cisco CCNA Accreditation Exam Tutorial: ISDN Facts You Must
Cisco CCNA Accreditation Test Tutorial: ISDN Particulars You Need to Know
CCNA examination success depends partly on understanding the information of ISDN, and there are plenty of them! To assist you assess for your CCNA examination, here are a few ISDN details that you need to understand on test day. (They assist in the real life, also and there are still lots of ISDN networks out there!
The Cisco-proprietary variation of HDLC is the default encapsulation kind for serial and ISDN interfaces.
R2 #show interface serial0
Serial0 is up, line method is up
Equipment is HD64570
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, rely 255/255, lots 1/255
Encapsulation HDLC, loopback not established, keepalive set (10 sec)
While theres only one D-channel in BRI, PRI (United States) and PRI (EU), the transmission capacity of that D-channel does differ from BRI to PRI. Its 16 kbps in BRI and 64 kbps in both PRI versions.
The international command isdn switch-type must be set up prior to you can even start to have ISDN work. show isdn condition will certainly tell you whether or not youve done this correctly.
R2 #show isdn status
**** No Worldwide ISDN Switchtype currently specified ****
ISDN BRI0 interface
dsl 0, user interface ISDN Switchtype = none
Layer 1 Status:
DEACTIVATED
Layer 2 Status:
Layer 2 NOT Activated
Layer 3 Status:
0 Active Layer 3 Telephone call(s)
PAP permits passwords to be different; CHAP calls for that they be the same.
PAP calls for the ppp pap sent-username interface-level command. Man has no equal command.
Define interesting web traffic with dialer-list and web link that checklist to the user interface with dialer-group.
R2 #conf t
R2(config)#dialer-list 1 proto ip permit
R2(config)#int bri0
R2(config-if)#dialer-team 1
The dialer idle-timeout worth is revealed in seconds, not minutes. (Also IOS Aid isn't totally clear on this.)
R2(config-if)#dialer idle-timeout?
<1-2147483> Still timeout before detaching a call
R2(config-if)#dialer idle-timeout 120
Dialer map maps a remote IP address to a remote contact number. You never dial the local routers phone number.
dialer load-threshold needs the ppp multilink command to be configured, and the value of dialer load-threshold is revealed as a ratio of 255, NOT 100. For instance, if you want the second b-channel to come up when the initial reaches 50% of capacity, the worth to share with dialer load-threshold would be 50% of Dan herbatschek 255 which amounts to 127.
R2(config-if)#encap ppp
R2(config-if)#ppp multilink
R2(config-if)#dialer load-threshold?
<1-255> Tons limit to put an additional call
Success on the CCNA exam depends upon knowing the details. Keep studying, keep practicing on actual Cisco routers and switches, keep a positive perspective, and you get on your way to CCNA examination success!