diff --git a/sys/cam/ctl/ctl_frontend_iscsi.c b/sys/cam/ctl/ctl_frontend_iscsi.c
--- a/sys/cam/ctl/ctl_frontend_iscsi.c
+++ b/sys/cam/ctl/ctl_frontend_iscsi.c
@@ -917,7 +917,7 @@
 		cfiscsi_session_terminate(cs);
 		return;
 	}
-	cdw->cdw_datasn++;
+	cdw->cdw_datasn += request->ip_additional_pdus + 1;
 
 	io = cdw->cdw_ctl_io;
 	KASSERT((io->io_hdr.flags & CTL_FLAG_DATA_MASK) != CTL_FLAG_DATA_IN,
diff --git a/sys/dev/cxgbe/cxgbei/cxgbei.h b/sys/dev/cxgbe/cxgbei/cxgbei.h
--- a/sys/dev/cxgbe/cxgbei/cxgbei.h
+++ b/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;
 };
diff --git a/sys/dev/cxgbe/cxgbei/cxgbei.c b/sys/dev/cxgbe/cxgbei/cxgbei.c
--- a/sys/dev/cxgbe/cxgbei/cxgbei.c
+++ b/sys/dev/cxgbe/cxgbei/cxgbei.c
@@ -583,10 +583,12 @@
 		    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;
@@ -595,17 +597,19 @@
 			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_additional_pdus = npdus - 1;
 		} else {
 			MPASS(htobe32(bhsdo->bhsdo_datasn) ==
 			    cmp->last_datasn + 1);
 			npdus = 1;
+			cmp->last_datasn = htobe32(bhsdo->bhsdo_datasn);
 		}
 
 		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 {
diff --git a/sys/dev/cxgbe/cxgbei/icl_cxgbei.c b/sys/dev/cxgbe/cxgbei/icl_cxgbei.c
--- a/sys/dev/cxgbe/cxgbei/icl_cxgbei.c
+++ b/sys/dev/cxgbe/cxgbei/icl_cxgbei.c
@@ -1346,7 +1346,6 @@
 	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);
diff --git a/sys/dev/iscsi/icl.h b/sys/dev/iscsi/icl.h
--- a/sys/dev/iscsi/icl.h
+++ b/sys/dev/iscsi/icl.h
@@ -75,6 +75,14 @@
 	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 additional on-the-wire PDUs.
+	 * For PDUs that match on-the-wire PDUs, this should be set to
+	 * zero.
+	 */
+	u_int			ip_additional_pdus;
+
 	/*
 	 * User (initiator or provider) private fields.
 	 */