House Voicemail



I am building a system with two GXV3240 and eight GXP1628 on a UCM6102. Outside access is though a SIP trunk with one DID.

There will be a ring group of all of the phones that will default to a voicemail box. Is there any way to provide a visual indication on ALL phones that there is a message in the group mailbox?



You will need to set-up a group mail box for the ring group members and then establish it as the default destination so that unanswered calls are sent there. Once a message is left, then all member of the group mail will get an MWI that vmail awaits.

Be advised that that group mail may pose some challenges in how it is used effectively -

  1. it is an individual vmail sent to each member. If one member reads the vmail, this does not affect the other members…it will still be in their box with their MWI blinking. They may need to coordinate with one another in order to prevent duplication of effort as each tries to respond to it.
  2. The group mail box will need someone assigned to it so as to manage its contents effectively. Vmails remain in the box just like a normal vmail box until someone or the cleaner deletes them.


That is the way it is working now which is not very desirable.

Rather than using a group mailbox, can a single extension’s mailbox be monitored by an MWI on all phones?


Yes, but only if you set up the extension on every phone using an available, extra line key. The issue is how the system has to activate the mwi.


It appears this is a feature already deployed.

PBX > Call Features > Group Voicemail. Create an account here, do not add any members (this voicemail will keep a copy of the message).
On the phones monitor this extension number as “Voicemail” in the BLF type. This should show the voicemail icon and MWI light, when pressing the BLF it will access the 1 voicemail account, add this to as many phones as you like.

I covered it in ticket 20151013005749 (13 October 2015) with grand stream.


I have seen your reply to this request in a few threads. I understand the Group Voicemail setup. I have setup a Group Voicemail at extension 660, with no members. How do I add the key setting on the phone? I have a GXP6160, and I have tried setting the Virtual Multi-Purpose Key to “Voicemail”, with a value of 660, but it only checks MY voicemail. I have also tried setting it as “BLF”, but it then shows a greyed out icon, and it doesn’t do anything when pressed.

Can you please clarify " monitor this extension number as “Voicemail” in the BLF type"?


Actually, it doesnt work… you cant monitor Group Voicemail like you think you can (the ticket i opened, Grandstream “corrected” to say it doesnt work)…

The only get around i did was create an extension (call it Voicemail or something), then list the concurrent connections to the amount of phones you need to register (i am not sure if theres a maximum).

This “extension” needs to be added to each phone as an “account”. As its a “group” generally you will push calls to it via a ring group, hat would allow to “foroward to voicemail” then select that extension.

Now that light will show up RED on every phone that has a voicemail in that box (as ANY account on a grandstream phone will also subscribe for voicemail on that account), its as easy as pressing that button to collect the voicemail, more importantly when the voicemail is deleted (or read) EVERY account like will go off once its collected.

I am not sure why Grandstream has not fixed this as its boarding on 4 years now, freePBX and Cisco work like this, Grandstream does as well, except you can subscribe to a MWI on the Group Voicemail box, Asterisk works like this as well (which is Grandstreams engine). Really have no idea why this has not been fixed.

If you need more help, call me (timezone is EST)


Thanks for the reply. I ended up going the second account route also. It does seem tedious: our old “simple” TalkSwitch system did this with no issues.


the easiest thing is to create a single voice box, example extension 220.
The 220 registers it on all phones as a second account and will notify you of all the messages.