Hi,

We have some Snom M9 handsets which are using the latest Snom firware. If they are set to DND I get an "Unavailable" message on a Draytek 350 phone handset, not the extensions voicemail. This is despite the Draytek 3150 being set to "voicemail on busy" for all extensions. If I call the extension directly from an external number i.e. mobile phone I get a single beep tone and then cut off.

An example:

1. Ext 25 set to DND on Snom M9

2. Ext 17 calls ext 25 and receives unavailble

3. Ext 17 then hangs up

This is only an issue with the M9 handsets.

I have raised a ticket with Snom and they inform me thee handset is sending the correct SIP RFC response - see below:

Hello there,

I'm sorry to say so but the M9 is sending the correct SIP response. (Please see the corresponding RFC section.)

Most PBXs are able to interpret this response and initiate the appropriate action.

603 Decline would only be applicable if the incoming call gets rejected explicitly by the user (per call)

madigan

Snom accept this is not really a bug in the Draytek but they do say:

I wouldn't really consider it as a bug but in order to overcome this interoperability problem, Draytek should implement the "480 Do Not Disturb" SIP message to make sure that the correct action is being taken when calling a snom phone in DND mode.

Please could someone have a look into this for me, as we are using a few M9 handsets. Alternatively, if there is any way to work around this at the Draytek end please let me know.

The Draytek PBX is running the latest firmware:

Model Name : VigorIPPBX 3510
Firmware Version : 3.5.5.3
VOIP Module Information
Firmware Version : 2.6.4 (EN)

Thanks for the assistance