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interconexion with pstn!

hi, i'am a beeginer in cisco, i am preparing the exam of ccna, and i would like to know hwo to intercnect tow distant site via pstn( telephone).

i have two cisco router (26.20) and 2 modem us robotics.

thank you very mutch.


Re: interconexion with pstn!

Connect the aux port of either routers, to respective modems using a roll over cable.

2620 - aux --roll over cable---rj45-db25 adapter - USR modem -------PSTN------

---USRmodem - rj45-db25 adapter - roll over cable - aux - 2620

on the 2620 you can configure dialer profiles, one for dial in and other for dial out.

Give a "show line" and find the async line number of (TTY number) of AUX port.

create an async interface as follows.

int loopback 0

ip add

int async

no ip add

encapsulation ppp

dialer in-band

dialer pool-member 10

async default routing

ppp authentication chap callin

int dialer 1

ip unnumbered loopback 0

encapsulation ppp

dialer remote-name

dialer pool 10

dialer idle-timeout

dialer string

dialer-group 1

ppp authentication chap callin

int dialer 2

ip unnumbered loopback 0

encapsulation ppp

dialer pool 10

dialer-group 1

dialer remote-name

ppp authentication chap callin

dialer idle-timeout

username password

ip route dialer 1

dialer-list 1 protocol ip permit

line aux 0

modem InOut

transport input all

stopbits 1

speed 115200

flowcontrol hardware

Note that a similar conifiguration would appear in the second 2620 router. Usernames configured on each router, should be the name of the remote router. Passwords should match on both routers. Both routers can run a default route pointing to the Dialer interface. Dialer 1 is the interface used for dial out, while Dialer 2 is the interface for dial in. Note that in Dialer 2 there is no dial string configured.

Hope this helps!

Cisco Employee

Re: interconexion with pstn!

Here is the link which will explain you how to connect modem with a router

After that following url will help you for config

After that you will find many sample configs based on different scenarios at following url

One good link for aux-to-aux connection

Locate "External Modems (AUX/Console Ports)" on above url