diff --git a/driver/vhci/vhci_vhub.c b/driver/vhci/vhci_vhub.c
index fe819eed..e8c594d4 100644
--- a/driver/vhci/vhci_vhub.c
+++ b/driver/vhci/vhci_vhub.c
@@ -176,7 +176,6 @@ vhub_get_ports_status(pvhub_dev_t vhub, ioctl_usbip_vhci_get_ports_status *st)
 {
 	pvpdo_dev_t	vpdo;
 	PLIST_ENTRY	entry;
-	unsigned char	n_used_ports = 0;
 
 	PAGED_CODE();
 
@@ -191,12 +190,11 @@ vhub_get_ports_status(pvhub_dev_t vhub, ioctl_usbip_vhci_get_ports_status *st)
 			DBGE(DBG_VHUB, "strange port");
 			continue;
 		}
-		n_used_ports++;
 		st->port_status[vpdo->port] = 1;
 	}
 	ExReleaseFastMutex(&vhub->Mutex);
 
-	st->n_used_ports = n_used_ports;
+	st->n_max_ports = 127;
 	return STATUS_SUCCESS;
 }
 
diff --git a/driver/vhci_ude/vhci_hc.c b/driver/vhci_ude/vhci_hc.c
index 5b7b1ff6..869a01ad 100644
--- a/driver/vhci_ude/vhci_hc.c
+++ b/driver/vhci_ude/vhci_hc.c
@@ -1,7 +1,7 @@
 #include "vhci_driver.h"
 #include "vhci_hc.tmh"
 
-#define MAX_HUB_PORTS		4
+#define MAX_HUB_PORTS		16
 
 #include "usbip_vhci_api.h"
 
diff --git a/driver/vhci_ude/vhci_ioctl.c b/driver/vhci_ude/vhci_ioctl.c
index 53992270..03b41ea2 100644
--- a/driver/vhci_ude/vhci_ioctl.c
+++ b/driver/vhci_ude/vhci_ioctl.c
@@ -12,7 +12,6 @@ static VOID
 get_ports_status(pctx_vhci_t vhci, ioctl_usbip_vhci_get_ports_status *ports_status)
 {
 	ULONG	i;
-	unsigned char	n_used_ports = 0;
 
 	TRD(IOCTL, "Enter\n");
 
@@ -24,13 +23,12 @@ get_ports_status(pctx_vhci_t vhci, ioctl_usbip_vhci_get_ports_status *ports_stat
 		pctx_vusb_t	vusb = vhci->vusbs[i];
 		if (vusb != NULL) {
 			ports_status->port_status[i] = 1;
-			n_used_ports++;
 		}
 	}
 
 	WdfSpinLockRelease(vhci->spin_lock);
 
-	ports_status->n_used_ports = n_used_ports;
+	ports_status->n_max_ports = (UCHAR)vhci->n_max_ports;
 
 	TRD(IOCTL, "Leave\n");
 }
diff --git a/include/usbip_vhci_api.h b/include/usbip_vhci_api.h
index 45277c04..de08592e 100644
--- a/include/usbip_vhci_api.h
+++ b/include/usbip_vhci_api.h
@@ -70,10 +70,11 @@ typedef struct _vhci_pluginfo
 	unsigned char	dscr_conf[9];
 } vhci_pluginfo_t, *pvhci_pluginfo_t;
 
+/* usbip-win assumes max port is 127 */
 typedef struct _ioctl_usbip_vhci_get_ports_status
 {
-	/* usbip-win assumes max port is 127 */
-	unsigned char n_used_ports;
+	/* maximum number of ports */
+	unsigned char n_max_ports;
 	unsigned char port_status[127];
 } ioctl_usbip_vhci_get_ports_status;
 
diff --git a/userspace/src/usbip/usbip_attach.c b/userspace/src/usbip/usbip_attach.c
index b6f469e3..c5e9c74d 100644
--- a/userspace/src/usbip/usbip_attach.c
+++ b/userspace/src/usbip/usbip_attach.c
@@ -214,6 +214,9 @@ attach_device(const char *host, const char *busid, const char *serial)
 		case ERR_NOTEXIST:
 			err("non-existent bus id: %s", busid);
 			break;
+		case ERR_PORTFULL:
+			err("no available port");
+			break;
 		default:
 			err("failed to attach");
 			break;
diff --git a/userspace/src/usbip/usbip_vhci.c b/userspace/src/usbip/usbip_vhci.c
index 6b4e5693..cc9ac8c6 100644
--- a/userspace/src/usbip/usbip_vhci.c
+++ b/userspace/src/usbip/usbip_vhci.c
@@ -91,7 +91,7 @@ usbip_vhci_get_free_port(HANDLE hdev)
 
 	if (usbip_vhci_get_ports_status(hdev, &status))
 		return -1;
-	for (i = 0; i < 127; i++) {
+	for (i = 0; i < status.n_max_ports; i++) {
 		if (!status.port_status[i])
 			return i;
 	}
@@ -99,7 +99,7 @@ usbip_vhci_get_free_port(HANDLE hdev)
 }
 
 static int
-get_n_used_ports(HANDLE hdev)
+get_n_max_ports(HANDLE hdev)
 {
 	ioctl_usbip_vhci_get_ports_status	status;
 	int	res;
@@ -107,23 +107,23 @@ get_n_used_ports(HANDLE hdev)
 	res = usbip_vhci_get_ports_status(hdev, &status);
 	if (res < 0)
 		return res;
-	return status.n_used_ports;
+	return status.n_max_ports;
 }
 
 int
 usbip_vhci_get_imported_devs(HANDLE hdev, pioctl_usbip_vhci_imported_dev_t *pidevs)
 {
 	ioctl_usbip_vhci_imported_dev	*idevs;
-	int	n_used_ports;
+	int	n_max_ports;
 	unsigned long	len_out, len_returned;
 
-	n_used_ports = get_n_used_ports(hdev);
-	if (n_used_ports < 0) {
-		dbg("failed to get the number of used ports: %s", dbg_errcode(n_used_ports));
+	n_max_ports = get_n_max_ports(hdev);
+	if (n_max_ports < 0) {
+		dbg("failed to get the number of used ports: %s", dbg_errcode(n_max_ports));
 		return ERR_GENERAL;
 	}
 
-	len_out = sizeof(ioctl_usbip_vhci_imported_dev) * (n_used_ports + 1);
+	len_out = sizeof(ioctl_usbip_vhci_imported_dev) * (n_max_ports + 1);
 	idevs = (ioctl_usbip_vhci_imported_dev *)malloc(len_out);
 	if (idevs == NULL) {
 		dbg("out of memory");
@@ -150,7 +150,7 @@ usbip_vhci_attach_device(HANDLE hdev, pvhci_pluginfo_t pluginfo)
 
 	if (!DeviceIoControl(hdev, IOCTL_USBIP_VHCI_PLUGIN_HARDWARE,
 		pluginfo, pluginfo->size, NULL, 0, &unused, NULL)) {
-		err("usbip_vhci_attach_device: DeviceIoControl failed: err: 0x%lx", GetLastError());
+		dbg("usbip_vhci_attach_device: DeviceIoControl failed: err: 0x%lx", GetLastError());
 		return -1;
 	}