Gigaset C610a registers but won't accept calls

I figured this out and I felt I should share.
I bought a Gigaset C610a IP/DECT6 cordless (and a few C610h handsets) they are a bit quirky, but I like them.

With a default extension configuration, I could get them to register & they could call any other extension, but no extension could call them, asterisk -rvvvvvvvv showed :
WARNING[2838]: chan_sip.c:20406 handle_response_invite: Received response: “Forbidden” from (Ext number calling the Gigaset)

This annoyed me for a few days, until I recreated the extension and ONLY changed “Internal Auto Answer” from the default of Intercom to DISABLED. That fixed it, calls ring in fine now.

I hope this helps somebody, Oh, and it’s a pretty nice phone, G722 voice support works great!


Works great but doesn’t support Intercom?

With so many supported phones I don’t understand why anyone would want to use an unsupported phone.

I agree, but this problem doesn’t really affect me. I’m testing it for use mixed with POTS, I like it for that.

Maybe in a few firmware rev’s it will get better. The hardware is already good.

The phone is registering (I am using Vitelity DID), but when I try to call the device, I get a CHANUNAVAIL error.

Can you explain your solution better. I tried looking for “Internal Auto Answer”, but could not locate that setting.


That’s exactly what the intercom function does. If you choose the internals calls option its the same as dialing *80 on every call internally.

One point you might not not know is that Freepbx looks at the Ui identifier to determine the handset type and uses the correct alert info for different vendor phones.

I have a Gigaset phone too. The a510h with the n300 base. The only complaint that I have with these is that the batteries do not last anywhere close to the time stated on the Gigaset web site. That says 210 hours standby and 20 hours talk time. I only get about 24-48 hours standby and about 2 hours talk time. Trying to resolve with the suppliers at the moment so hopefully I can sort this out.

By the way I have two handsets:

One configured to an external VoIP provider (
One configured to use my Asterisk server.

I have several Voip providers registered to my FreePBX server, I really only got this phone because of price, G722 support, and to test the local POTS capability for another deployment (but I don’t use that feature at my home).
In the extension configuration on FreePBX, there is a setting for “Internal Auto Answer” which (I assume) must send some info in the SIP header that the phone doesn’t like and refuses the call (Skyking is about 1000X more knowledgeable on that subject) It’s the only change that is needed to get the phones to ring inbound calls on FreePBX, so I posted it here so the Google will find it when the next guy has this problem. You need to call Vitelity as you are registered directly with them, not a local * box (Or, grab an old PC, and install FreePBX in-between!).

I have the 610a (base w/1 handset) 2 610h (matching handsets) and 1 A58H (which is the handset that looks just like yours. I went through the battery charge/discharge procedure with all the phones (in the book) and, just so I could see how long it took, (BTW, I have each handset registered on my * server as a separate number) I charged them up, then I called from one extension to another thru my FreePBX until they died on their own, and that took about 8 hours. One of the things that attracted me to these phones is the batteries, they are 2, standard, Ni-Mh AAA batteries, but the ones they come with are kinda cheapo GP 700ah , when mine get to not charging, I’ll replace them with Duracell 1000ah

I suggest you try that first.
Good luck guys.


That being said, IDK if I’d want my cordless to answer without human interaction (but that’s me) I’m overall happy with the phone, I do wish it was a bit bigger.

In the interest of science (or just my curiosity) Just today I purchased a set of Energizer 850ah NiMh batteries, I’m going to clock a full discharge of the stock batteries (calling a conference) from all my phones, swap them for the energizers, charge & discharge those and compare.

Why? Because I’m a geek.



Thanks for the advice about the batteries. I will give those a go. I don’t know why they are not lasting me that long but I do leave them out of the charging cradle as per the instructions in the handset guide until they discharge and then charge them fully before using.