isdn status deactivated

[Vuvi]

Ciao ragazzi,
ho un cisco 801, se lo collego alla linea isdn il comando isdn status mi da layer1 deactivated. Se collego un'altro modem isdn la connessione viene effettuata....ricollego il cisco, isdn status mi da activated, funziona per qualche secondo e poi il nulla...........
cosa può essere?

questa è la configurazione:

interface Dialer 1
ip address negotiated
ip nat outside
encapsulation ppp
dialer in-band
dialer idle-timeout 120
dialer string 7027020000
dialer hold-queue 10
dialer-group 1
dialer load-threshold 1 either
ppp authentication chap pap callin
ppp chap hostname [email protected]
ppp chap password xxx
ppp pap sent-username [email protected] password xxx
no ppp multilink
no cdp enable
!
interface Ethernet 0
no shutdown
description Rete LAN
ip address 192.168.0.70 255.255.255.0
ip nat inside
keepalive 10
!
interface BRI 0
no shutdown
description connected to ISP
no ip address
ip nat outside
dialer rotary-group 1

no access-list 1
access-list 1 permit 192.168.0.0 0.0.0.255
access-list 101 deny tcp any any eq 139
access-list 101 deny udp any any eq 137
access-list 101 deny udp any any eq 138
access-list 101 permit ip any any
!
! Dialer Control List 1
!
no dialer-list 1
dialer-list 1 protocol ip list 101

ip nat translation timeout 86400
ip nat translation tcp-timeout 86400
ip nat translation udp-timeout 300
ip nat translation dns-timeout 60
ip nat translation finrst-timeout 60
ip nat inside source list 1 interface Dialer 1 overload


ip route 0.0.0.0 0.0.0.0 Dialer 1
no ip http server
snmp-server community public RO
no snmp-server location
no snmp-server contact

[infingardo]

posta un sh isdn status

[Vuvi]

Global ISDN Switchtype = basic-net3
ISDN BRI0 interface
dsl 0, interface ISDN Switchtype = basic-net3
Layer 1 Status:
DEACTIVATED
Layer 2 Status:
Layer 2 NOT Activated
Layer 3 Status:
0 Active Layer 3 Call(s)
Active dsl 0 CCBs = 0
The Free Channel Mask: 0x80000003
Number of L2 Discards = 0, L2 Session ID = 0