From CLI:
-- Executing Dial("SIP/213-081a65a8", "SIP/299|20|t") in new stack
-- Called 299
-- SIP/299-081923c8 is ringing
-- SIP/299-081923c8 is ringing
-- SIP/299-081923c8 is ringing
-- SIP/299-081923c8 is ringing
-- SIP/299-081923c8 is ringing
-- Executing NoOp("SIP/207-081a91c8", "Trying 299@desk-phones") in new stack
-- Executing Pickup("SIP/207-081a91c8", "299@desk-phones") in new stack
== Spawn extension (internal, **299, 2) exited non-zero on 'SIP/207-081a91c8'
-- SIP/299-081923c8 is ringing
-- SIP/299-081923c8 is ringing
-- SIP/299-081923c8 is ringing
-- SIP/299-081923c8 is ringing
From extensions.conf
exten => _**2XX,1,NoOp(Trying ${EXTEN:2}@desk-phones)
exten => _**2XX,n,Pickup(${EXTEN:2}@desk-phones)