We have grandstreams and a few customers that want to
block there outbound
caller id. Has anyone done this? I'd really like the *30 and *31 feature
to work but if you turn it on the openser server blocks the call.
You can enable Anonymous CALL ID in the frontend of the grandstream
phones. when you enable it, the grandstream sends sip: "Anonymous"
<username(a)blah.de> in the from field. Sometimes this isnt enough and you
have to change the username in the from field via openser also.