fail to login in using telnet.
1. Replace one VCT of TP3006 and import the orignal configuration to the new codec.
but the codec still can't be online at AMX host
2. Check the logs of VCT
3. we suspect the password of AMX host was different with VCT
4. AMX host's apiuser password was null and can't be changed
VCT's apiuser default password was Change_Me
5. we use command below to modify the password of VCT to null
mc modifydebugpasswd apiuser Change_Me null null
6. the problem solved.