2 ringback only

[mushechka]

Hello everybody.

I have this situation, i'm dialing a number through my gateway, as5300 and as5350, i hear 2 ringback and than dead air. Can you help?

[kyaw_thu]

provide more info...

[mushechka]

I'm using SIP protocol. From my SIP phone i dial a PSTN number,that should go through one of my gateways. When i dialed, the call is connected, i hear only two ringbacks in my SIP phone, and then dead air.

[swvaroot]

What is the topology? What are the gateways? What tools are available?

[mushechka]

Hello

Tahnk you for your interess and trying to help me.

I have a SIP sever, and 3 Gateways as5300 and as5350, When i make a call to a destination from VoIP, the negotiation begin beween the gateway and the SIP server, everything go good, Invite, then trying, then 180 ringing, then 183 sesion progess, i hear the ringbacks, then suddenly the gateway send a Cancel packet to the SIP server, and i hear dead air.