diff --git a/zaptel/zaptel-base.c b/zaptel/zaptel-base.c

index e2931bf..5929e65 100644

--- zaptel/zaptel-base.c

+++ zaptel/zaptel-base.c

@@ -1906,6 +1908,13 @@ static ssize_t zt_chan_write(struct file *file, const char *usrbuf, size_t count

 		} else {

 			if (copy_from_user(chan->writebuf[res], usrbuf, amnt))

 				return -EFAULT;

+

+			if ((chan->flags & ZT_FLAG_HDLC) && chan->span->ioctl != NULL){

+				if (chan->span->ioctl(chan, ZT_DCHAN_TX_V2, amnt)==0){

+					return amnt;

+				}

+			}

+

 			chan->writen[res] = amnt;

 		}

 		chan->writeidx[res] = 0;

diff -dur zaptel.orig/zaptel.h zaptel/zaptel.h

--- zaptel.orig/zaptel.h	2005-10-03 10:52:43.094205960 -0400

+++ zaptel/zaptel.h	2005-10-03 10:48:53.974037520 -0400

@@ -611,6 +611,10 @@

  *  60-80 are reserved for private drivers

  *  80-85 are reserved for dynamic span stuff

  */

+#define ZT_DCHAN_TX 	_IOR (ZT_CODE, 60, int)

+#define ZT_DCHAN_TX_V1  ZT_DCHAN_TX

+#define ZT_DCHAN_TX_V2  ZT_DCHAN_TX

+

 /*

  * Create a dynamic span