a Malaysia hotel site, a ip phone 7910 user name 7051 registered to DND service, though most of other phones can not call 7051, some ip phones such as 7053 still can call to 7051.
1.first we can judge 7051 already registered to DND service, or else other phones can call to 7051. also we can use command to check.
[%eSpace U1980(config)]#show subscriber dn 7051 type newservice
Rights Register Information
------------------- -------- -----------
OPERATOR DISCONNECT Y
OPERATOR INSERT Y
VOICEMAIL_CFB Y [UMSno:2]
VOICEMAIL_CFNR Y [UMSno:2]
2.why some phones can not call to 7051, but some phones still can, we should compare these ip phones user configuration.
show subscriber dn 7053
we find that 7053 config the telephonist attribute. then we delete the telephonist for 7053, now 7053 can not call to 7051. so we can prove even 7051 has DVD service, as long as other phone users has the telephonist attribute, they still can call to 7051.