This document describes how to disable FXS port 2 on 18x ATA
Port 2 of 18x ATA is constantly trying to register to CUCM 7.x and wants to disable it.
To disable the second analog Foreign Exchange Station (FXS) port on the ATA
Use value 0 to disable the port(s) you are not using:
EPID1 or SID1 for Line 2 or Port 2
By default, both Cisco ATA FXS ports are enabled for Cisco CallManager registration. If you do not want to add the Phone 2 FXS port to Cisco CallManager, you must change the Cisco ATA EPID1orSID1 parameter value to 0 to disable the Phone 2 port. (To disable the Phone 1 port, you must change the EPID0orSID0 parameter value to 0)
SIDx specifies whether to enable the Phone 1 and/or Phone 2 ports on the Cisco ATA to register with Cisco CallManager. (EPIDx is not for SCCP.) SIDx can be one of these values:
0 - Disables the port. The port does not attempt to register with Cisco CallManager.
. or - Uses the default Skinny ID, which is the Cisco ATA MAC address (MAC) for the Phone 1 port and MAC[1-5]+01 for the Phone 2 port. The port attempts to register with Cisco CallManager.You need to fabricate a MAC address for the Phone 2 port by dropping the two left-most digits from the Cisco ATA MAC address and add the digits 01 to the right-most portion of the MAC address.
Example - If the MAC address of the Cisco ATA is 00070EA26032, then the fabricated MAC address for the Phone 2