Index: sys/cam/ctl/ctl_frontend_iscsi.c
===================================================================
--- sys/cam/ctl/ctl_frontend_iscsi.c
+++ sys/cam/ctl/ctl_frontend_iscsi.c
@@ -909,7 +909,12 @@
 		return;
 	}
 
+#if 0
+	if (cdw->cdw_datasn + (request->ip_npdus == 0 ? 0 :
+	    request->ip_npdus - 1) != ntohl(bhsdo->bhsdo_datasn)) {
+#else
 	if (cdw->cdw_datasn != ntohl(bhsdo->bhsdo_datasn)) {
+#endif
 		CFISCSI_SESSION_WARN(cs, "received Data-Out PDU with "
 		    "DataSN %u, while expected %u; dropping connection",
 		    ntohl(bhsdo->bhsdo_datasn), cdw->cdw_datasn);
@@ -917,7 +922,10 @@
 		cfiscsi_session_terminate(cs);
 		return;
 	}
-	cdw->cdw_datasn++;
+	if (request->ip_npdus != 0)
+		cdw->cdw_datasn += request->ip_npdus;
+	else
+		cdw->cdw_datasn++;
 
 	io = cdw->cdw_ctl_io;
 	KASSERT((io->io_hdr.flags & CTL_FLAG_DATA_MASK) != CTL_FLAG_DATA_IN,
Index: sys/dev/cxgbe/cxgbei/cxgbei.h
===================================================================
--- sys/dev/cxgbe/cxgbei/cxgbei.h
+++ sys/dev/cxgbe/cxgbei/cxgbei.h
@@ -58,7 +58,6 @@
 
 	uint32_t tt;		/* Transfer tag. */
 
-	uint32_t next_datasn;
 	uint32_t next_buffer_offset;
 	uint32_t last_datasn;
 };
Index: sys/dev/cxgbe/cxgbei/cxgbei.c
===================================================================
--- sys/dev/cxgbe/cxgbei/cxgbei.c
+++ sys/dev/cxgbe/cxgbei/cxgbei.c
@@ -591,10 +591,12 @@
 		    cmp->next_buffer_offset;
 
 		if (prev_seg_len != 0) {
+			uint32_t orig_datasn;
+
 			/*
-			 * Since cfiscsi doesn't know about previous
-			 * headers, pretend that the entire r2t data
-			 * length was received in this single segment.
+			 * Return a "large" PDU representing the burst
+			 * of PDUs.  Adjust the offset and length of
+			 * this PDU to represent the entire burst.
 			 */
 			ip->ip_data_len += prev_seg_len;
 			bhsdo->bhsdo_data_segment_len[2] = ip->ip_data_len;
@@ -603,11 +605,16 @@
 			bhsdo->bhsdo_buffer_offset =
 			    htobe32(cmp->next_buffer_offset);
 
-			npdus = htobe32(bhsdo->bhsdo_datasn) - cmp->last_datasn;
+			orig_datasn = htobe32(bhsdo->bhsdo_datasn);
+			npdus = orig_datasn - cmp->last_datasn;
+			bhsdo->bhsdo_datasn = htobe32(cmp->last_datasn + 1);
+			cmp->last_datasn = orig_datasn;
+			ip->ip_npdus = npdus;
 		} else {
 			MPASS(htobe32(bhsdo->bhsdo_datasn) ==
 			    cmp->last_datasn + 1);
 			npdus = 1;
+			cmp->last_datasn = htobe32(bhsdo->bhsdo_datasn);
 		}
 
 #if 1
@@ -617,9 +624,6 @@
 		    htobe32(bhsdo->bhsdo_datasn));
 #endif
 		cmp->next_buffer_offset += ip->ip_data_len;
-		cmp->last_datasn = htobe32(bhsdo->bhsdo_datasn);
-		bhsdo->bhsdo_datasn = htobe32(cmp->next_datasn);
-		cmp->next_datasn++;
 		toep->ofld_rxq->rx_iscsi_ddp_pdus += npdus;
 		toep->ofld_rxq->rx_iscsi_ddp_octets += ip->ip_data_len;
 	} else {
Index: sys/dev/cxgbe/cxgbei/icl_cxgbei.c
===================================================================
--- sys/dev/cxgbe/cxgbei/icl_cxgbei.c
+++ sys/dev/cxgbe/cxgbei/icl_cxgbei.c
@@ -1359,7 +1359,6 @@
 	prsv->prsv_tag &= ~pr->pr_alias_mask;
 	prsv->prsv_tag |= alias << pr->pr_alias_shift & pr->pr_alias_mask;
 
-	ddp->cmp.next_datasn = 0;
 	ddp->cmp.last_datasn = -1;
 	cxgbei_insert_cmp(icc, &ddp->cmp, prsv->prsv_tag);
 	*tttp = htobe32(prsv->prsv_tag);
Index: sys/dev/iscsi/icl.h
===================================================================
--- sys/dev/iscsi/icl.h
+++ sys/dev/iscsi/icl.h
@@ -75,6 +75,13 @@
 	size_t			ip_data_len;
 	struct mbuf		*ip_data_mbuf;
 
+	/*
+	 * When a "large" received PDU represents multiple on-the-wire
+	 * PDUs, this is the count of on-the-wire PDUs.  For PDUs that
+	 * match on-the-wire PDUs, this should be set to zero.
+	 */
+	u_int			ip_npdus;
+
 	/*
 	 * User (initiator or provider) private fields.
 	 */