Hi. My setup is:
2Wire 3800HGV-B Router
Two SMCGS16-SMART EZ Switches
SPA9000 (Firmware 6.15, Proxy Network Interface: WAN). The SPA9000's internet port is plugged into one of the SMC switches.
Three SPA1001 units, one SPA2102 unit, all of which register with the SPA9000.
The SPA9000 is behind the router's firewall; I've found no need to forward ports.
The SPA9000 has line 1 registering with Broadvoice.
So, on all the extensions, I can make external calls and receive them. Audio is two-way and clear.
But, if I call an internal extension from another internal extension, the called extension can hear the caller. But the caller cannot hear the called extension.
I've searched these forums and tried various settings on the SPA9000 and the SPA1001 and SPA2102 units. No joy. I'm baffled.
Does anyone have any ideas?