if (!t_check_trans()) {
    xlog("L_INFO", "No transaction found with t_check_trans(), trying t_lookup_cancel()\n");
    # Try to find the transaction using branch and Call-ID
    $var(branch) = $(hdr(Via){param.value,branch});
    if (!t_lookup_cancel()) {
        xlog("L_WARN", "No transaction found for CANCEL - $ci with branch $var(branch)\n");
        sl_reply("481", "Call Leg/Transaction Does Not Exist");
        exit;
    }
    xlog("L_INFO", "Found transaction using t_lookup_cancel()\n");
}

# Extract destination from original request
if ($ru != "") {
    $du = $ru;
    xlog("L_INFO", "Setting destination from R-URI: $du\n");
} else {
    xlog("L_WARN", "No R-URI found for CANCEL\n");
}

# Add debugging
xlog("L_INFO", "Forwarding CANCEL to $du for call $ci\n");

if (ds_is_from_list()) {
    ds_load_unset();
    xlog("L_INFO", "Unset dispatcher load for destination\n");
}

# Handle the client ID and call counting
if (is_present_hf("X-VICIdial-Client-Id")) {
    $var(client_id) = $(hdr(X-VICIdial-Client-Id));
    if ($var(client_id) =~ "^(CID_[0-9]+)-[a-z]$") {
        $var(parent_id) = $(var(client_id){re.subst,/^(CID_[0-9]+)-[a-z]$/\1/});
    } else {
        $var(parent_id) = $var(client_id);
    }

    if($var(parent_id) != $null) {
        lock("calls_$var(parent_id)");
        if($sht(clientCalls=>$var(parent_id)) > 0) {
            $sht(clientCalls=>$var(parent_id)) = $sht(clientCalls=>$var(parent_id)) - 1;
            xlog("L_INFO", "CANCEL: Decremented call count for $var(parent_id) to $sht(clientCalls=>$var(parent_id))\n");
        }
        unlock("calls_$var(parent_id)");
    }
}

# Send 200 OK response for the CANCEL
t_reply("200", "OK");

# Force the relay of CANCEL to the destination
t_relay();
exit;