can't conference calls together on Mitel 5330 phone

[Terry.TNC]

We have a Mitel 5000 phone system, and we're testing out some Mitel 5330 ip phones.  One problem that's shown up during testing is that we can't conference external calls together.  Here are the instructions from the phone user guide:

To form a Conference when a two-party call is already in place, or to add another party to an existing Conference:
1. Press the TRANS/CONF key (image of arrow, vertical bar, and 3 heads)
2. Dial the number of the next party.
3. Wait for an answer.
4. Press the TRANS/CONF key

When we reach step 4, it always drops the 2nd external call.  Do I need to change something in the programming on these phones, or am I missing something more obvious?

[acejavelin]

We have a Mitel 5000 phone system, and we're testing out some Mitel 5330 ip phones.  One problem that's shown up during testing is that we can't conference external calls together.  Here are the instructions from the phone user guide:

To form a Conference when a two-party call is already in place, or to add another party to an existing Conference:
1. Press the TRANS/CONF key (image of arrow, vertical bar, and 3 heads)
2. Dial the number of the next party.
3. Wait for an answer.
4. Press the TRANS/CONF key

When we reach step 4, it always drops the 2nd external call.  Do I need to change something in the programming on these phones, or am I missing something more obvious?

There is no "Trans/Conf" key on the 5000 (MiVoice Office 250), those instructions are for the 3300 system (MiVoice Business)... the 5000 system uses a separate key for Transfer to Ringing (the Arrow/3 heads) and you have to program a conference key or use FEATURE+5 for conference.

The process is actually a little different on the 5000... you press Conference on an existing call, make the new call to 3rd party, press Conference, make new call to 4th party, etc... until you have called all participants  have been called, then press Conference twice to join all parties. 

So properly modifying your instructions...

To form a Conference when a two-party call is already in place, or to add another party to an existing Conference:
1. Press the CONFERENCE key (on programmable key on phone)
2. Dial the number of the next party.
3. Wait for an answer.
4. Press the CONFERENCE key twice to join all parties.

[Terry.TNC]

Thank you, I have since found similar threads explaining the process as you presented it.    It almost works, too.

If I use the (wrong) Transfer button then dial 8 for outgoing line, then the 10-digit number, then it successfully dials out.
If I use the (correct) Conference button (Feature 5 on the keymap), then dial exactly as above, it doesn't actually dial the outside number.  My digits sit there on the display, but no outgoing connection is made.  It works the same if I use the SPCL (circle-X button) 5 buttons on the phone rather than the programmed key.

Am I missing some other setting in my system somewhere that would send the call to an outgoing line?  I've tried with or without the preceding 8, but it doesn't make a difference.

[pexecutone]

It should be press Conference key (feature code 5) then press 8 for an outside line and dial the DID. Once the call connects it's Conference, Conference to join the calls. Unless there aren't any available trunks. I don't see how it doesn't at least call the intended DID. I'm assuming the intend number can be called when not trying to create a conference call.

[Terry.TNC]

I don't know what changed.  I made other keymap changes today, and when I returned to the Conference problem... it worked just fine this time!

The only thing I can think of is that we recently had a system reboot because of some hung voicemail-to-email, and maybe the reboot fixed something else?