IP phone to IP phone through an IP trunk Issue

Is your phone connecting to a hosted PBX provider or is it connecting to a premise-based IP PBX? Incoming and outgoing calls are usually handled by two separate connections between your PBX and the service provider SIP trunk. Sounds like a registration problem with the SIP trunk. There is nothing you can do from the phone itself to fix this.

This sounds like an RTP stream issue. While SIP runs on port 5060 by default, the actual audio is run on much higher ports, 10000 and up. If your pbx system is not on a public address and you are forwarding traffic to your pbx via a router, check the RTP port range in your pbx and make sure you are forwarding those ports correctly. By putting the call on hold, you stop sending out audio traffic restart sending audio when you pick the call back up. By forwarding the entire RTP range to your pbx, this should fix your issue.

SAy what? I have no idea what you are asking. You are correct, teh 46xx phones are 1/2 duplex, nothing you can do about it.

can somebody help me we have a Sip connection between a mitel 3300 and Cisco callmanager only the conference call doesn't work who can help me out

The mute button is the top right button, it's a clear colored button. When it's lit and orange it's muted.

Upgrade to the new skype version!!

Check your firewall settings. Make sure you can pass voice traffic. Can you Skype?

Similar issue - brand new phone - but incoming calls (skype or landline) would ring - and then nothing, and outgoing calls the handset would just reset.

The handset would just lose signal constantly (less than 2 meters from the base station).

The phone shipped with the latest software - but eventually I reinstalled it - no change, then de-registered the handset, powered everything down and re-registered the handset and that *seems* to have done it .....

So
1 - reflash / re-install latest software from philips website (even if the phone already has the same version)
2 - de-register handset (follow instructions)
3 - unplug base station and remove batteries from handset
4 - turn on base station, put batteries in handset
5 - re register handset (follow instructions in manual)

and that seems to do it.

I gather you are using an IP phone. I would have to say that the only way to trouble shoot is to use a protocol analyzer. If you connect it within the IP path you will be able to see both ends of the call and determine if the call was received or not and if the other end is responding to your call. Your IP PBX might be the problem I would run a diagnostic on it and if it fails, I would suggest calling the manufacture to see if there are any tests you can run.

You've got an IP issue somewhere in your setup. It sounds like the call is being lost and then the phone is querying the DNS server to find out where it should be looking for the call. Do you have a VOIP server name or it's IP address in the setup? Are you using DHCP or manually assigning IP addresses? If the VOIP server is not on a static IP, I would fix that first. Post back here the answers and we can look at it further.