diff --git a/CHANGELOG.md b/CHANGELOG.md
index c9cb01e2..21ae2e01 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -84,11 +84,16 @@ Developers may need to change their code
   
 ### Minor features
 
+* Clearer debug levels `clicon_debug()`:
+  * 1: Logical debug message
+  * 2: Input and output packets
+  * 3: Message dump in hex, xpath parse trees 
 * Added `ISO/IEC 10646` encodings to XML parser: `&#[0-9]+;` and `&#[0-9a-fA-F]+;`
 * Added `CLIXON_CLIENT_SSH` to client API to communicate remotely via SSH netconf sub-system
 
 ### Corrected Bugs
 
+* Fixed: Initialized session-id to 1 instead of 0 following ietf-netconf.yang
 * Fixed: [snmpwalk doesn't show properly SNMP boolean values which equal false](https://github.com/clicon/clixon/issues/400)
 * Fixed: yang-library: Remove revision if empty instead of sending empty revision
   * This was a change from RFC 7895 to RFC 8525
diff --git a/apps/backend/backend_client.c b/apps/backend/backend_client.c
index ec150d25..0c3bdf50 100644
--- a/apps/backend/backend_client.c
+++ b/apps/backend/backend_client.c
@@ -1476,13 +1476,8 @@ from_client_hello(clicon_handle       h,
                   cbuf                *cbret)
 {
     int      retval = -1;
-    uint32_t id;
     char    *val;
 
-    if (clicon_session_id_get(h, &id) < 0){
-        clicon_err(OE_NETCONF, ENOENT, "session_id not set");
-        goto done;
-    }
     if ((val = xml_find_type_value(x, "cl", "transport", CX_ATTR)) != NULL){
         if ((ce->ce_transport = strdup(val)) == NULL){
             clicon_err(OE_UNIX, errno, "strdup");
@@ -1495,16 +1490,15 @@ from_client_hello(clicon_handle       h,
             goto done;
         }
     }
-    id++;
-    clicon_session_id_set(h, id);
     cprintf(cbret, "<hello xmlns=\"%s\"><session-id>%u</session-id></hello>",
-            NETCONF_BASE_NAMESPACE, id);
+            NETCONF_BASE_NAMESPACE, ce->ce_id);
     retval = 0;
  done:
     return retval;
 }
 
-/*! An internal clicon message has arrived from a client. Receive and dispatch.
+/*! An internal clixon NETCONF message has arrived from a local client. Receive and dispatch.
+ *
  * @param[in]   h    Clicon handle
  * @param[in]   ce   Client entry (from)
  * @param[in]   msg  Incoming message
@@ -1531,7 +1525,7 @@ from_client_msg(clicon_handle        h,
     yang_stmt           *ymod;
     cxobj               *xnacm = NULL;
     cxobj               *xret = NULL;
-    uint32_t             id;
+    uint32_t             op_id; /* session number from internal NETCONF protocol */
     enum nacm_credentials_t creds;
     char                *rpcname;
     char                *rpcprefix;
@@ -1550,7 +1544,7 @@ from_client_msg(clicon_handle        h,
     /* Decode msg from client -> xml top (ct) and session id 
      * Bind is a part of the decode function
      */
-    if ((ret = clicon_msg_decode(msg, yspec, &id, &xt, &xret)) < 0){
+    if ((ret = clicon_msg_decode(msg, yspec, &op_id, &xt, &xret)) < 0){
         if (netconf_malformed_message(cbret, "XML parse error") < 0)
             goto done;
         goto reply;
@@ -1560,6 +1554,14 @@ from_client_msg(clicon_handle        h,
             goto done;
         goto reply;
     }
+    /* Sanity check:
+     * op_id from internal message can be out-of-sync from client's sessions-id for the following reasons:
+     * 1. Its a hello when the client starts with op_id=0 to get its proper id on hello reply
+     * 2. The backend has restarted and the client uses an old op_id
+     */
+    if (op_id != 0 && ce->ce_id != op_id){
+        clicon_debug(1, "%s out-of-order sequence op-id:%u ce_id:%u", __FUNCTION__, op_id, ce->ce_id);
+    }
     /* Check for empty frame (no mesaages), return empty message, not clear from RFC what to do */
     if (xml_child_nr_type(xt, CX_ELMNT) == 0){
         if (netconf_malformed_message(cbret, "Empty message in netconf rpc frame")< 0)
@@ -1616,8 +1618,6 @@ from_client_msg(clicon_handle        h,
         ce->ce_out_rpc_errors++; /*  Number of <rpc-reply> messages sent that contained an <rpc-error> */
         goto reply;
     }
-    ce->ce_id = id;
-
     /* As a side-effect, this expands xt with default values according to "report-all"
      * This may not be correct, the RFC does not mention expanding default values for
      * input RPC
diff --git a/apps/backend/backend_main.c b/apps/backend/backend_main.c
index 7de8ac41..d23ecfc0 100644
--- a/apps/backend/backend_main.c
+++ b/apps/backend/backend_main.c
@@ -1053,7 +1053,7 @@ main(int    argc,
         goto done;
 
     /* Start session-id for clients */
-    clicon_session_id_set(h, 0);
+    clicon_session_id_set(h, 1);
 #if 0 /* debug */
     /* Enable this to get prints of datastore and session status */
     if (0 && clicon_debug_get() && 
diff --git a/apps/backend/clixon_backend_handle.c b/apps/backend/clixon_backend_handle.c
index 2d738684..cb94559e 100644
--- a/apps/backend/clixon_backend_handle.c
+++ b/apps/backend/clixon_backend_handle.c
@@ -146,6 +146,11 @@ backend_client_add(clicon_handle    h,
     memcpy(&ce->ce_addr, addr, sizeof(*addr));
     ce->ce_next = bh->bh_ce_list;
     ce->ce_handle = h;
+    if (clicon_session_id_get(h, &ce->ce_id) < 0){
+        clicon_err(OE_NETCONF, ENOENT, "session_id not set");
+        return NULL;
+    }
+    clicon_session_id_set(h, ce->ce_id + 1);
     gettimeofday(&ce->ce_time, NULL);
     bh->bh_ce_list = ce;
     return ce;
diff --git a/apps/netconf/netconf_main.c b/apps/netconf/netconf_main.c
index f7abd04e..e65d662d 100644
--- a/apps/netconf/netconf_main.c
+++ b/apps/netconf/netconf_main.c
@@ -987,10 +987,6 @@ main(int    argc,
     /* Call start function is all plugins before we go interactive */
     if (clixon_plugin_start_all(h) < 0)
         goto done;
-#if 1
-    /* XXX get session id from backend hello */
-    clicon_session_id_set(h, getpid()); 
-#endif
 
     /* Send hello request to backend to get session-id back
      * This is done once at the beginning of the session and then this is
diff --git a/apps/snmp/snmp_main.c b/apps/snmp/snmp_main.c
index 5a4ccd43..76a1b751 100644
--- a/apps/snmp/snmp_main.c
+++ b/apps/snmp/snmp_main.c
@@ -517,9 +517,6 @@ main(int    argc,
     if (dbg)
         clicon_option_dump(h, dbg);
     
-    /* Get session id from backend hello */
-    clicon_session_id_set(h, getpid()); 
-
     /* Send hello request to backend to get session-id back
      * This is done once at the beginning of the session and then this is
      * used by the client, even though new TCP sessions are created for
diff --git a/lib/clixon/clixon_proto.h b/lib/clixon/clixon_proto.h
index 15c69bf4..74f92f40 100644
--- a/lib/clixon/clixon_proto.h
+++ b/lib/clixon/clixon_proto.h
@@ -54,7 +54,7 @@ enum format_enum{
 /* Protocol message header */
 struct clicon_msg {
     uint32_t    op_len;     /* length of whole message: body+header, network byte order. */
-    uint32_t    op_id;      /* session-id. network byte order. */
+    uint32_t    op_id;      /* session-id. network byte order. 1..max(u32), can be zero in client hello */
     char        op_body[0]; /* rest of message, actual data */
 };
 
diff --git a/lib/src/clixon_data.c b/lib/src/clixon_data.c
index ac5c5527..daaca13c 100644
--- a/lib/src/clixon_data.c
+++ b/lib/src/clixon_data.c
@@ -840,7 +840,7 @@ clicon_session_id_del(clicon_handle h)
 
 /*! Set session id
  * @param[in]  h   Clicon handle
- * @param[in]  id  Session id
+ * @param[in]  id  Session id (in range 1..max uint32)
  * @retval     0   OK
  * @retval    -1   Error
  * Session-ids survive TCP sessions that are created for each message sent to the backend.
diff --git a/lib/src/clixon_log.c b/lib/src/clixon_log.c
index fcb0bdb6..5db0dbed 100644
--- a/lib/src/clixon_log.c
+++ b/lib/src/clixon_log.c
@@ -367,10 +367,12 @@ clicon_debug_get(void)
  *      print message if level >= dbglevel.
  * The message is sent to clicon_log. EIther to syslog, stderr or both, depending on 
  * clicon_log_init() setting
+ * The dbgdebug level strategy is:
+ *                       1: Logical debug message
+ *                       2: Input and output packets
+ *                       3: Message dump in hex, xpath parse trees 
  * 
- * @param[in] dbglevel   0 always called (dont do this: not really a dbg message)
- *                       1 default level if passed -D
- *                       2.. Higher debug levels
+ * @param[in] dbglevel   0: No debug, 1-3: increasing levels of debug
  * @param[in] format     Message to print as argv.
  * @see clicon_debug_xml Specialization for XML tree
  */
diff --git a/lib/src/clixon_proto.c b/lib/src/clixon_proto.c
index 6efef361..25ccf91c 100644
--- a/lib/src/clixon_proto.c
+++ b/lib/src/clixon_proto.c
@@ -417,7 +417,7 @@ clicon_msg_rcv(int                s,
         clicon_err(OE_CFG, errno, "body too short");
         goto done;
     }
-    if (clicon_debug_get() > 1)
+    if (clicon_debug_get() > 2)
         msg_dump(*msg);
     retval = 0;
   done:
diff --git a/lib/src/clixon_xpath.c b/lib/src/clixon_xpath.c
index f45dc0b1..fd2e7927 100644
--- a/lib/src/clixon_xpath.c
+++ b/lib/src/clixon_xpath.c
@@ -550,13 +550,13 @@ xpath_parse(const char  *xpath,
         xpath_scan_exit(&xpy);
         goto done;
     }
-    if (clicon_debug_get() > 1){
+    if (clicon_debug_get() > 2){
         if ((cb = cbuf_new()) == NULL){
             clicon_err(OE_XML, errno, "cbuf_new");
             goto done;
         }
         xpath_tree_print_cb(cb, xpy.xpy_top);
-        clicon_debug(2, "xpath parse tree:\n%s", cbuf_get(cb));
+        clicon_debug(3, "xpath parse tree:\n%s", cbuf_get(cb));
     }
     xpath_parse_exit(&xpy);
     xpath_scan_exit(&xpy);
diff --git a/test/test_snmp_entity.sh b/test/test_snmp_entity.sh
index cf806d91..49755114 100755
--- a/test/test_snmp_entity.sh
+++ b/test/test_snmp_entity.sh
@@ -103,7 +103,7 @@ cat <<EOF > $fstate
 EOF
 
 function testinit(){
-    new "test params: -f $cfg -- -sS $fstate"
+    new "test params: -s init -f $cfg -- -sS $fstate"
     if [ $BE -ne 0 ]; then
     # Kill old backend and start a new one
     new "kill old backend"
diff --git a/test/test_snmp_get.sh b/test/test_snmp_get.sh
index e82ccb30..d6463fea 100755
--- a/test/test_snmp_get.sh
+++ b/test/test_snmp_get.sh
@@ -99,7 +99,7 @@ cat <<EOF > $fstate
 EOF
 
 function testinit(){
-    new "test params: -f $cfg -- -sS $fstate"
+    new "test params: -s init -f $cfg -- -sS $fstate"
     if [ $BE -ne 0 ]; then
         # Kill old backend and start a new one
         new "kill old backend"
diff --git a/test/test_snmp_ifmib.sh b/test/test_snmp_ifmib.sh
index 5dc419b6..1b574cbc 100755
--- a/test/test_snmp_ifmib.sh
+++ b/test/test_snmp_ifmib.sh
@@ -163,7 +163,7 @@ EOF
 #   IF-MIB::ifSpecific.1 = OID: SNMPv2-SMI::zeroDotZero
 
 function testinit(){
-    new "test params: -f $cfg -- -sS $fstate"
+    new "test params: -s init -f $cfg -- -sS $fstate"
     if [ $BE -ne 0 ]; then
         # Kill old backend and start a new one
         new "kill old backend"
diff --git a/test/test_snmp_rowstatus.sh b/test/test_snmp_rowstatus.sh
index 7a3995b3..eb9382d4 100755
--- a/test/test_snmp_rowstatus.sh
+++ b/test/test_snmp_rowstatus.sh
@@ -65,7 +65,7 @@ cat <<EOF > $dir/startup_db
 EOF
 
 function testinit(){
-    new "test params: -f $cfg"
+    new "test params: -s startup -f $cfg"
 
     if [ $BE -ne 0 ]; then
         # Kill old backend and start a new one
diff --git a/test/test_snmp_set.sh b/test/test_snmp_set.sh
index d2de145b..e2d2b3d6 100755
--- a/test/test_snmp_set.sh
+++ b/test/test_snmp_set.sh
@@ -115,7 +115,7 @@ EOF
 fi
 
 function testinit(){
-    new "test params: -f $cfg"
+    new "test params: -s startup -f $cfg"
 
     if [ $BE -ne 0 ]; then
         # Kill old backend and start a new one
diff --git a/test/test_snmp_system.sh b/test/test_snmp_system.sh
index 98bd59f3..19c2e156 100755
--- a/test/test_snmp_system.sh
+++ b/test/test_snmp_system.sh
@@ -88,7 +88,7 @@ cat <<EOF > $fstate
 EOF
 
 function testinit(){
-    new "test params: -f $cfg -- -sS $fstate"
+    new "test params: -s init -f $cfg -- -sS $fstate"
     if [ $BE -ne 0 ]; then
     # Kill old backend and start a new one
     new "kill old backend"