Limit 1 call ISDN + SIP

Hi all,

i need some suggestion…my current configuration is:

1 trunks sip euteliavoip (only for outgoing calls with hidden caller ID)
1 trunks myISDN IN and OUT ( 2 numbers available on my ISDN device)

5 Extension (IP301 )

Everything works fine, but i’ve a problem:
when i’m at office and i made an outgoing call it’s ok, but if someone calls me on my ISDN number at the same time, he got a free tone but i cannot answer coz i’m busy with the first call.

Even if only one extension is busy (VOIP or ISDN) i need that for every incoming call the system replies with a busy tone.

Is there someone who can give me a suggestion about that problem?

thx a lot


You have to set the call limits for the sip phones if you want them to signal busy when they are in use, so in sip.conf, try set call-limit=2 (two concurrent calls per phone, to be able to transfer the call) and busy-limit=1 (when the phone is in use signal busy) for every sip phone.


Marco Bruni

Can you confirm that this worked for you?

I have been struggling for months to get busy-limit working. I am using Asterisk 1.4.21 and busy-limit just seems to be ignored. You set it to 1 and calls keep coming through. Set call-limit to 1 though and works as expected but then you cant transfer.


I just checked the sip.conf of one of our customers, it has limitonpeers set to yes in the general section, all sip phones have call-limit set to 1; as soon as one call is received/done phones report busy and people are able to do unattended transfe.
I would try set limitonpeers to yes and see what happens.


Marco Bruni