Allow subscribtion over IAX2 trunk


I have 2 offices connected over IAX2 trunk. There is Cisco SPA 525G2 phone with SPA-500 module in one office. I’d want t monitor extensions connected to Asterisk server in 2nd office.

For 1st office subscription/BLF works fine:

<Unit_1_Key_1 group=“Att_Console/Unit_1”>fnc=sd+cp+blf;[email protected]</Unit_1_Key_1>

where is LAN ip in 1st office

but for 2nd office BLF does not work

<Unit_1_Key_2 group=“Att_Console/Unit_1”>fnc=sd+cp+blf;[email protected]</Unit_1_Key_2>

where is public IP of 2nd office

pbx*CLI> sip show subscriptions Peer User Call ID Extension Last state Type Mailbox Expiry 0 active SIP subscriptions

On phone I see that subscription failed.

Where can I allow subscription over trunk or for fixed IP?