These calls were outbound on a PRI.
I continued testing this weekend.
If you make the call on hook, in speaker mode it works.
If you pick up the handset then go back to speaker phone you get one way audio,intermittently.
The microphone doesnt transmit.
I tested 2 phones and went back to core switch at the NBX. It happened there also. I swapped the core switch and issue still remained.
I am using 3com 4400's
System 3com V3001R
Software Ver 6.0.63