We have a site we just signed with 500 plus phones. The site has multiple subsnets across the network the phones will be installed on. When plugging in phones on a different subnet, they will not check into the 3cx server as expected. We have a few phones on site for testing. I started playing around the GDMS and still I can't not get the phones to check in.

1. We have noticed that some phones out of the box do not send the subscribe broadcast at bootup. We are monitoring broadcast traffic and some push the subscribe messages and some dont.

2. We installed a SBC on 1 of the subnets, the phones that sent the broadcast were seen by the SBC/3CX.

3.i tried updated the firmware through GDMS(all phones do show in GDMS) and the phones will not take the firmware.

Anyone else have these issues? Any suggestions on the easiest way to get these phones to check into 3cx ?

Any help is appreciated