drop the DSR

try pulse-time command

pulse-time

To enable pulsing DTR signal intervals on the serial interfaces, use the pulse-time interface configuration command. Use the no form of this command to restore the default interval.

pulse-time seconds no pulse-time Syntax Description

seconds

Integer that specifies the DTR signal interval in seconds.

Default

Interface configuration Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

When the serial line protocol goes down (for example, because of loss of synchronization) the interface hardware is reset and the DTR signal is held inactive for at least the specified interval. This function is useful for handling encrypting or other similar devices that use the toggling of the DTR signal to resynchronize. Example

The following example enables DTR pulse signals for three seconds on serial interface 2:

interface serial 2 pulse-time 3

Fanks The same trouble but with AUX port Can u help

chat-script Dialout ABORT ERROR ABORT BUSY "" "AT" OK "ATDT \\T" TIMEOUT

! interface Async65 no ip address no ip directed-broadcast encapsulation ppp no ip mroute-cache load-interval 30 keepalive 1 dialer in-band dialer pool-member 20 async default routing ppp authentication chap callin ! interface Dialer10 ip address 10.200.23.246 255.255.255.252 no ip directed-broadcast encapsulation ppp no ip mroute-cache load-interval 30 keepalive 1 dialer remote-name XXXX dialer pool 20 dialer idle-timeout 900 dialer string 9222222 dialer-group 1 ppp quality 15 ppp authentication chap callin ppp timeout retry 15 !

line aux 0 exec-timeout 0 0 script dialer Dialout modem InOut modem autoconfigure type MY_USR_MODEM transport input all stopbits 1 speed 115200 flowcontrol hardware

@@@@@@@@@@On o side

interface Async73 ip address 10.200.23.245 255.255.255.252 encapsulation ppp no ip route-cache no ip mroute-cache async default routing async mode interactive no peer default ip address no keepalive ppp authentication chap !

line con 0 line 2 flush-at-activation stopbits 1 speed 115200 flowcontrol hardware

line aux 0 modem InOut transport input all autoselect during-login autoselect ppp speed 115200 flowcontrol hardware

line vty 0 4

From the standpoint of the router, its async interface (line) is always DTE not DCE. Therefore, it controls DTR, not DSR/DCD - DSR/DCD are controlled by the OTHER side.

If you have modem control configured on the router (modem inout, modem dialin, modem dtr-active), then the router will always drop DTR when PPP goes down.

Regards,

Aaron