Overview
The Grandstream GXP-2000 handsets are a relatively inexpensive handset that support most, but not all features offered by SipXecs. They are '4 line' handsets, supporting attended and unattended transfers, PoE, full duplex speakerphones, on-handset conferencing, etc.
The display is customizable, including a bitmap graphic, allowing the handset to be 'branded', using tools from the manufacturer's website.
The handsets can be successfully provisioned using the SipXecs provisioning server, allowing for centralized configuration. The configuration is downloaded each time the phones are booted.
Known Issues
Music on Hold
At the time of writing, I have not found a way to implement Music on Hold with the grandstream handsets. Instead of music, the party on hold hears an double tone every few seconds (about 6?), to indicate that the call is still live.
Caller places call on hold
At the time of writing, we have discovered an issue which only arises under very specific cirumstances. When the issue occurs, a call placed on hold cannot be retrieved from hold. The issue only occurs in the case where all the following are true:
- Handset of the caller is configured to use a vlan
- Handset of the called party is configured to send DTMF tones via RTP (RFC2833). Unfortunately, this is the only supported, and thus default, option for SipXecs provisioned handsets.
- The caller is the person to put the call on hold. The issue does not occur if the called party puts the call on hold.
When these circumstances aline, the handset fails to transmit the proper packets to put the call on hold, even though it reports that it does to it's syslog server.
The issue is currently under investigation.
Useful Details
Phonebook
The 'phonebook' on the handset is limited to 349 entries in the current firmware revision. Entries in the phonebook override 'caller-id name' for incoming calls, and are responsible for outgoing 'called name' lookup. The phonebook can be either manually entered on the handset, or downloaded from a server. The file 'gs_phonebook.xml' will be downloaded from the configured server, which can be hosted via HTTP or TFTP.
The configuration screens on the phone allude to an 'LDAP' phonebook. This is a serious misnomer, as it has nothing whatsoever to do with LDAP. Instead, if configured, the phone makes an HTTP call to a script (could be php, .cgi, etc) which is expected to return the phonebook results in the same .xml format as is used for the 'gs_phonebook.xml'. This script CAN be passed parameters, which it should use to limit the returned results. Unfortunately, the 'LDAP phonebook' is NOT used for the 'called name lookup' or the incoming caller-id override as described above.