I am converting phones from a ROLM 9751 PBX over to a Cisco UC solution. I have one GAI-tronics analog "Intrinsically-Safe" (IS) 262-001 phone with a 263-000 Isolation Barrier Unit (IBU) between the phone and PBX (or analog VGW). On the ROLM PBX, there is dial-tone on the IS phone (through the IBU), however, when connecting the IBU to the analog VGW, the phone does not have dial-tone. There is dial-tone from the voice gateway to the IBU. I've verified that the ROLM PBX was loop-start, as is the VGW.
The IBU is powered with 120v AC and ensures "safe power levels" to the IS phone in the gaseous areas. The cable from IBU to PBX/VGW is Cat3 twisted pair, and the cable between IBU and IS phone is shielded TP, with the shield earth-grounded by the IBU.
I'm at a loss...other than to travel to the site and take a look myself- hopefully looking at the setup could stir some ideas. Has anyone every dealt with GAI-tronics explosive proof phones/IBUs before in the Cisco UC world? Any thoughts or ideas would be GREATLY appreciated...
THANKS!!
