asterisk cli:

zap show status
Description                              Alarms     IRQ        bpviol     CRC4
T4XXP (PCI) Card 0 Span 1                RED        0          0          0
T4XXP (PCI) Card 0 Span 2                UNCONFIGUR 0          0          0
T4XXP (PCI) Card 0 Span 3                UNCONFIGUR 0          0          0
T4XXP (PCI) Card 0 Span 4                UNCONFIGUR 0          0          0

zapata.conf
[channels]
group=1
language=en
usecallerid=yes
callerid=asreceived
context=default
echocancel=64
echocancelwhenbridged=yes
rxgain=1.0
txgain=1.0
signalling=pri_cpe
switchtype=5ess
channel => 1-23

zaptel.conf
loadzone=us
defaultzone=us
span=1,0,0,esf,b8zs
bchan=1-23
dchan=24

asterisk cli when dialing:
Executing AGI("SIP/1031-08827a20", "agi://127.0.0.1:4577/call_log") in new stack
    -- AGI Script agi://127.0.0.1:4577/call_log completed, returning 0
    -- Executing Dial("SIP/1031-08827a20", "Zap/1/12062036815||tTo") in new stack
Oct 18 21:56:00 NOTICE[18751]: app_dial.c:1076 dial_exec_full: Unable to create channel of type 'Zap' (cause 0 - Unknown)
  == Everyone is busy/congested at this time (1:0/0/1)
    -- Executing Hangup("SIP/1031-08827a20", "") in new stack
  == Spawn extension (default, 912062036815, 3) exited non-zero on 'SIP/1031-08827a20'
    -- Executing DeadAGI("SIP/1031-08827a20", "agi://127.0.0.1:4577/call_log") in new stack
    -- AGI Script agi://127.0.0.1:4577/call_log completed, returning 0
    -- Executing DeadAGI("SIP/1031-08827a20", "agi://127.0.0.1:4577/VD_hangup--HVcauses--PRI-----NODEBUG-----16-----CHANUNAVAIL----------)") in new stack
    -- AGI Script agi://127.0.0.1:4577/VD_hangup--HVcauses--PRI-----NODEBUG-----16-----CHANUNAVAIL----------) completed, returning 0