I was trying to do this async callback in my lab. Have tried to get answer from books and Cisco website for quite some time but with no luck. Seek help from the group. By looking at the debug info, seemed the callback client is working OK but missed something on the callback server side as there was no callback. Callback server :- ================ c2509rj#sh run Building configuration... Current configuration: ! version 11.2 no service password-encryption no service udp-small-servers no service tcp-small-servers ! hostname c2509rj ! enable secret 5 $1$FNXZ$OXAMRvJMI90li81Ua.h3b1 ! username c2501 password 0 samepass chat-script call-c2501 ABORT ERROR "" "AT Z" OK "ATDT \T" TIMEOUT 30 CONNECT \c ! interface Loopback1 ip address 1.1.1.1 255.255.0.0 no logging event subif-link-status ! interface Ethernet0 no ip address no logging event subif-link-status shutdown ! interface Serial0 no ip address no logging event subif-link-status shutdown ! interface Async2 ip address 10.1.1.7 255.255.255.0 encapsulation ppp no logging event subif-link-status async mode interactive dialer in-band dialer callback-secure dialer idle-timeout 200 dialer wait-for-carrier-time 120 dialer map ip 10.1.1.8 name c2501 class dial1 102 dialer hold-queue 60 dialer-group 1 ppp callback accept ppp authentication chap ! no ip classless ! map-class dialer dial1 dialer callback-server username dialer-list 1 protocol ip permit ! line con 0 exec-timeout 0 0 line 1 no exec transport input all line 2 password samepass autoselect during-login autoselect ppp script callback call-c2501 login local modem InOut modem autoconfigure discovery transport input all stopbits 1 speed 115200 flowcontrol hardware line 3 8 line aux 0 line vty 0 4 login ! end Callback Client ============= c2501#sh run Building configuration... Current configuration: ! version 11.2 no service password-encryption no service udp-small-servers no service tcp-small-servers ! hostname c2501 ! ! username c2509rj password 0 samepass chat-script dial-c2509rj "" "AT Z" OK "ATDT \T" TIMEOUT 300 CONNECT \c ! interface Ethernet0 no ip address shutdown ! interface Serial0 no ip address shutdown no fair-queue ! interface Serial1 no ip address shutdown ! interface Async1 ip address 10.1.1.8 255.255.255.0 encapsulation ppp async mode interactive dialer in-band dialer map ip 10.1.1.7 name c2509rj 101 dialer-group 1 ppp callback request ppp authentication chap ! no ip classless ! dialer-list 1 protocol ip permit ! line con 0 exec-timeout 0 0 line aux 0 password samepass script dialer dial-c2509rj login local modem InOut modem autoconfigure discovery transport input all stopbits 1 rxspeed 38400 txspeed 38400 flowcontrol hardware line vty 0 4 login ! end Debug ======== c2501#ping 10.1.1.7 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 10.1.1.7, timeout is 2 seconds: Async1: Dialing cause ip (s=10.1.1.8, d=10.1.1.7) Async1: Attempting to dial 101 CHAT1: Attempting async line dialer script CHAT1: Dialing using Modem script: dial-c2509rj & System script: none CHAT1: process started CHAT1: Asserting DTR CHAT1: Chat script dial-c2509rj started CHAT1: Sending string: AT Z CHAT1: Expecting string: OK CHAT1: Completed match for expect: OK CHAT1: Sending string: ATDT \T CHAT1: Expecting string: CONNECT..... Success rate is 0 percent (0/5) c2501# CHAT1: Completed match for expect: CONNECT CHAT1: Sending string: \c CHAT1: Chat script dial-c2509rj finished, status = Success %LINK-3-UPDOWN: Interface Async1, changed state to up As1 PPP: Treating connection as a callout %LINK-3-UPDOWN: Interface Async2, changed state to up Async2: Dialer received incoming call from <unknown> Async2:Callback server starting to c2501 102 Async2: disconnecting call As1 PPP: Phase is AUTHENTICATING, by both As1 CHAP: O CHALLENGE id 9 len 26 from "c2501" As1 CHAP: I CHALLENGE id 9 len 28 from "c2509rj" As1 CHAP: O RESPONSE id 9 len 26 from "c2501" As1 CHAP: I SUCCESS id 9 len 4 As1 CHAP: I RESPONSE id 9 len 28 from "c2509rj" As1 CHAP: O SUCCESS id 9 len 4 Async1: Callback negotiated - waiting for server disconnect %LINK-5-CHANGED: Interface Async2, changed state to reset %LINK-5-CHANGED: Interface Async1, changed state to reset Callback client for c2509rj 101 created %LINK-3-UPDOWN: Interface Async2, changed state to down %LINK-3-UPDOWN: Interface Async1, changed state to down Async2: re-enable timeout callback triggered by dialer_timers Async2:beginning callback to c2501 102 Async2: Attempting to dial 102 CHAT2: Attempting async line dialer script CHAT2: no matching chat script found for 102 Async2: Unable to dial 102. : Dialing failed, 0 packets unqueued and discarded : unable to dial callback return call Freeing callback to c2501 102 Async1: re-enable timeout Async2: re-enable timeout No callback received from c2509rj 101 Freeing callback to c2509rj 101 ======================= _________________________________ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]