Backward feature sync between SNOM and FreePBX not working

Wen using SNOM 7XX with “server based” feature working ( via DTMF codes) then features like DND and CFW can be set from the phone and are reflected in FreePBX USer Control Portal. But when changing DND or CFW via the UCP, then the are not synced to the SNOM phone.

For this kind of backward synicng SNOM has a setting called “dfks1!: on” in the SIP settings to subscribe to “feature events”, but this is rejected by FreePBX 11 with “SIP/2.0 489 Bad Event” (see details below).

Is there any workaround or planned solution for SNOM phones?

SIP trace:

SUBSCRIBE sip:[email protected] SIP/2.0
v: SIP/2.0/UDP;branch=z9hG4bK-0mvuxbuu40aa;rport
f: sip:[email protected];tag=99679muo6y
t: sip:[email protected]
i: 03F8DE5571400E07E410B0BABE846630-x9yyrmcuabwz
Max-Forwards: 5
User-Agent: snom715/
m: sip:[email protected]:5060;line=5slglzg3;reg-id=1
Event: as-feature-event
Authorization: Digest username=“49”,realm=“asterisk”,nonce=“3a415f5c”,uri="sip:[email protected]",response=“199500d488504ef1fed6c79476d900ef”,algorithm=MD5
Expires: 3600
c: application/x-as-feature-event+xml
l: 0

Received from udp: at 27/8/2015 13:44:04:009 (444 bytes):

SIP/2.0 489 Bad Event
Via: SIP/2.0/UDP;branch=z9hG4bK-0mvuxbuu40aa;received=;rport=5060
From: sip:[email protected];tag=99679muo6y
To: sip:[email protected];tag=as16d7b909
Call-ID: 03F8DE5571400E07E410B0BABE846630-x9yyrmcuabwz
Server: FPBX-2.11.0(11.8.1)
Supported: replaces, timer
Content-Length: 0

Seems like SNOM and FreePBX UCP integration is not of interest to anyone ?


I have a similar issue with Cisco SPA525G2 phones. Everything is working fine with 6 phones installed exempt that I have this “SIP/2.0 489 Bad Event” right after “as-feature-event”

Did you manage to find out how to fix it ?

Thanks for your time

Asterisk doesnt support that event type

Ok then how can I disable this “as-feature-event” from my SPA? Any idea?

Look the GUI and manual? I dont have one to look myself.

On Yealink phones, this feature does the following:

The IP phone supports server-side Do Not Disturb (DND), Call Forward (CFWD) and Automatic Call Distribution (ACD) features. The as-feature-event feature allows the IP phone to synchronize the status of the following features with the server:

  • Do Not Disturb 
  • Call Forwarding Always (CFA) 
  • Call Forwarding Busy (CFB) 
  • Call Forwarding No Answer (CFNA) 

ACD  If the as-feature-event feature is enabled, a user changes the status of one of these features via web portal or feature access code (FAC), the server notifies the phone of the status change. Conversely, if the user changes the feature status on the IP phone, the IP phone notifies the server of the status change.

So, for this to work, every manufacturer that uses this feature is going to have to publish what they are doing with the request and provide insight into how the server needs to respond. I’ll bet a box of virtual donuts that every manufacturer is implementing this differently (like they do Paging pickup and custom ring-tones).

On the Yealink phones (the manual I found) this feature is set in the phone and should be turned off in normal Asterisk operation.