HELP!! Cisco ATA Second line

Hi all:

X ATA 186 line 1
ATA 186 line 2 \
D-Link Router —–IP—- Z ATA 186 line 1
Y ATA 186 line 1 / ATA 186 line 2
ATA 186 line 2

Using SIP behind D-link router
Box X has ports 10000 and 5060 forwarded
Box Y has ports 10001 and 5061 forwarded
Box X has UIDO = 1111, UID1 = 1122
Box y has UIDO = 2211, UID1 = 2222
Box Z has UIDO = 1111, UID1 = 1122
I am able to call from line 1 of boxes X,Y and Z to other line 1 (X, Y,Z)
Cannot call any line 2
When calling from line two the call reciever can hear me but I cannot hear them

Thanks in advance!!!

Joseph