Grandstream Handytone 503 and Caller ID

I can’t seem to get my HT-503 to pass caller ID info through to my analog telephones… they display only the SIP username which I defined in sip.conf.

I tried adding


to the HT-503 section in my sip.conf, but with that in place, the analog telephones dsiplayed “asreceived” for the caller id.

I’m not sure if the problem is with a setting in my asterisk config files, or if it might be an incorrect setting on the HT-503. I’m running the latest from the 1.2 series. Can anyone suggest a fix?