diff --git a/src/core/ddsi/CMakeLists.txt b/src/core/ddsi/CMakeLists.txt
index 077a422..74d2421 100644
--- a/src/core/ddsi/CMakeLists.txt
+++ b/src/core/ddsi/CMakeLists.txt
@@ -25,6 +25,7 @@ PREPEND(srcs_ddsi "${CMAKE_CURRENT_LIST_DIR}/src"
     ddsi_rhc_plugin.c
     ddsi_iid.c
     ddsi_tkmap.c
+    ddsi_vendor.c
     q_addrset.c
     q_bitset_inlines.c
     q_bswap.c
@@ -77,6 +78,7 @@ PREPEND(hdrs_private_ddsi "${CMAKE_CURRENT_LIST_DIR}/include/ddsi"
     ddsi_rhc_plugin.h
     ddsi_iid.h
     ddsi_tkmap.h
+    ddsi_vendor.h
     probes-constants.h
     q_addrset.h
     q_bitset.h
diff --git a/src/core/ddsi/include/ddsi/ddsi_vendor.h b/src/core/ddsi/include/ddsi/ddsi_vendor.h
new file mode 100644
index 0000000..a8f9953
--- /dev/null
+++ b/src/core/ddsi/include/ddsi/ddsi_vendor.h
@@ -0,0 +1,84 @@
+/*
+ * Copyright(c) 2019 ADLINK Technology Limited and others
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0, or the Eclipse Distribution License
+ * v. 1.0 which is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
+ */
+#ifndef DDSI_VENDOR_H
+#define DDSI_VENDOR_H
+
+#include <stdint.h>
+#include <stdbool.h>
+
+typedef struct {
+  uint8_t id[2];
+} nn_vendorid_t;
+
+/* All existing vendor codes have the major part equal to 1 (and this will probably be true for a long, long time) */
+#define NN_VENDORID_MINOR_RTI                0x01
+#define NN_VENDORID_MINOR_PRISMTECH_OSPL     0x02
+#define NN_VENDORID_MINOR_OCI                0x03
+#define NN_VENDORID_MINOR_MILSOFT            0x04
+#define NN_VENDORID_MINOR_KONGSBERG          0x05
+#define NN_VENDORID_MINOR_TWINOAKS           0x06
+#define NN_VENDORID_MINOR_LAKOTA             0x07
+#define NN_VENDORID_MINOR_ICOUP              0x08
+#define NN_VENDORID_MINOR_ETRI               0x09
+#define NN_VENDORID_MINOR_RTI_MICRO          0x0a
+#define NN_VENDORID_MINOR_PRISMTECH_JAVA     0x0b
+#define NN_VENDORID_MINOR_PRISMTECH_GATEWAY  0x0c
+#define NN_VENDORID_MINOR_PRISMTECH_LITE     0x0d
+#define NN_VENDORID_MINOR_TECHNICOLOR        0x0e
+#define NN_VENDORID_MINOR_EPROSIMA           0x0f
+#define NN_VENDORID_MINOR_ECLIPSE            0x10
+#define NN_VENDORID_MINOR_PRISMTECH_CLOUD    0x20
+
+#define NN_VENDORID_UNKNOWN ((nn_vendorid_t) {{ 0x00, 0x00 }})
+#define NN_VENDORID_ECLIPSE ((nn_vendorid_t) {{ 0x01, 0x10 }})
+
+#if defined (__cplusplus)
+extern "C" {
+#endif
+
+inline bool vendor_equals (nn_vendorid_t a, nn_vendorid_t b) {
+  return ((a.id[0] << 8) | a.id[1]) == ((b.id[0] << 8) | b.id[1]);
+}
+inline bool vendor_is_eclipse (nn_vendorid_t vendor) {
+  return vendor_equals (vendor, NN_VENDORID_ECLIPSE);
+}
+inline bool vendor_is_rti (nn_vendorid_t vendor) {
+  return vendor_equals (vendor, (nn_vendorid_t) { 0x01, NN_VENDORID_MINOR_RTI });
+}
+inline bool vendor_is_opensplice (nn_vendorid_t vendor) {
+  return vendor_equals (vendor, (nn_vendorid_t) { 0x01, NN_VENDORID_MINOR_PRISMTECH_OSPL });
+}
+inline bool vendor_is_twinoaks (nn_vendorid_t vendor) {
+  return vendor_equals (vendor, (nn_vendorid_t) { 0x01, NN_VENDORID_MINOR_TWINOAKS });
+}
+inline bool vendor_is_cloud (nn_vendorid_t vendor) {
+  return vendor_equals (vendor, (nn_vendorid_t) { 0x01, NN_VENDORID_MINOR_PRISMTECH_CLOUD });
+}
+inline bool vendor_is_eclipse_or_opensplice (nn_vendorid_t vendor) {
+  return vendor_is_eclipse (vendor) | vendor_is_opensplice (vendor);
+}
+inline bool vendor_is_prismtech (nn_vendorid_t vendor) {
+  return (vendor_equals (vendor, (nn_vendorid_t) { 0x01, NN_VENDORID_MINOR_PRISMTECH_OSPL }) ||
+          vendor_equals (vendor, (nn_vendorid_t) { 0x01, NN_VENDORID_MINOR_PRISMTECH_LITE }) ||
+          vendor_equals (vendor, (nn_vendorid_t) { 0x01, NN_VENDORID_MINOR_PRISMTECH_GATEWAY }) ||
+          vendor_equals (vendor, (nn_vendorid_t) { 0x01, NN_VENDORID_MINOR_PRISMTECH_JAVA }) ||
+          vendor_equals (vendor, (nn_vendorid_t) { 0x01, NN_VENDORID_MINOR_PRISMTECH_CLOUD }));
+}
+inline bool vendor_is_eclipse_or_prismtech (nn_vendorid_t vendor) {
+  return vendor_is_eclipse (vendor) || vendor_is_prismtech (vendor);
+}
+
+#if defined (__cplusplus)
+}
+#endif
+
+#endif /* DDSI_VENDOR_H */
diff --git a/src/core/ddsi/include/ddsi/q_misc.h b/src/core/ddsi/include/ddsi/q_misc.h
index 37a44b3..912ccb0 100644
--- a/src/core/ddsi/include/ddsi/q_misc.h
+++ b/src/core/ddsi/include/ddsi/q_misc.h
@@ -18,27 +18,25 @@
 extern "C" {
 #endif
 
-struct nn_guid;
+inline seqno_t fromSN (const nn_sequence_number_t sn) {
+  return ((seqno_t) sn.high << 32) | sn.low;
+}
+
+inline nn_sequence_number_t toSN (seqno_t n) {
+  nn_sequence_number_t x;
+  x.high = (int) (n >> 32);
+  x.low = (unsigned) n;
+  return x;
+}
 
-int vendor_is_lite (nn_vendorid_t vendor);
-int vendor_is_opensplice (nn_vendorid_t vid);
-int vendor_is_rti (nn_vendorid_t vendor);
-int vendor_is_twinoaks (nn_vendorid_t vendor);
-int vendor_is_prismtech (nn_vendorid_t vendor);
-int vendor_is_cloud (nn_vendorid_t vendor);
-int is_own_vendor (nn_vendorid_t vendor);
 unsigned char normalize_data_datafrag_flags (const SubmessageHeader_t *smhdr, int datafrag_as_data);
 
-seqno_t fromSN (const nn_sequence_number_t sn);
-nn_sequence_number_t toSN (seqno_t);
-
 #ifdef DDSI_INCLUDE_NETWORK_PARTITIONS
 int WildcardOverlap(char * p1, char * p2);
 #endif
 
 int ddsi2_patmatch (const char *pat, const char *str);
 
-
 uint32_t crc32_calc (const void *buf, size_t length);
 
 #if defined (__cplusplus)
diff --git a/src/core/ddsi/include/ddsi/q_protocol.h b/src/core/ddsi/include/ddsi/q_protocol.h
index 209719a..a29e19f 100644
--- a/src/core/ddsi/include/ddsi/q_protocol.h
+++ b/src/core/ddsi/include/ddsi/q_protocol.h
@@ -123,27 +123,6 @@ struct cdrstring {
 #define NN_LOCATOR_KIND_UDPv4MCGEN 0x4fff0000
 #define NN_LOCATOR_PORT_INVALID 0
 
-#define NN_VENDORID_UNKNOWN                {{ 0x00, 0x00 }}
-#define NN_VENDORID_RTI                    {{ 0x01, 0x01 }}
-#define NN_VENDORID_PRISMTECH_OSPL         {{ 0x01, 0x02 }}
-#define NN_VENDORID_OCI                    {{ 0x01, 0x03 }}
-#define NN_VENDORID_MILSOFT                {{ 0x01, 0x04 }}
-#define NN_VENDORID_KONGSBERG              {{ 0x01, 0x05 }}
-#define NN_VENDORID_TWINOAKS               {{ 0x01, 0x06 }}
-#define NN_VENDORID_LAKOTA                 {{ 0x01, 0x07 }}
-#define NN_VENDORID_ICOUP                  {{ 0x01, 0x08 }}
-#define NN_VENDORID_ETRI                   {{ 0x01, 0x09 }}
-#define NN_VENDORID_RTI_MICRO              {{ 0x01, 0x0a }}
-#define NN_VENDORID_PRISMTECH_JAVA         {{ 0x01, 0x0b }}
-#define NN_VENDORID_PRISMTECH_GATEWAY      {{ 0x01, 0x0c }}
-#define NN_VENDORID_PRISMTECH_LITE         {{ 0x01, 0x0d }}
-#define NN_VENDORID_TECHNICOLOR            {{ 0x01, 0x0e }}
-#define NN_VENDORID_EPROSIMA               {{ 0x01, 0x0f }}
-#define NN_VENDORID_PRISMTECH_CLOUD        {{ 0x01, 0x20 }}
-#define NN_VENDORID_ECLIPSE_CYCLONEDDS     {{ 0x01, 0x0d }} // Since CYCLONEDDS has no owner yet, it uses the same VENDORID as LITE
-
-#define MY_VENDOR_ID NN_VENDORID_ECLIPSE_CYCLONEDDS
-
 /* Only one specific version is grokked */
 #define RTPS_MAJOR 2
 #define RTPS_MINOR 1
@@ -155,15 +134,11 @@ typedef struct Header {
   nn_vendorid_t vendorid;
   nn_guid_prefix_t guid_prefix;
 } Header_t;
-#define NN_PROTOCOLID_INITIALIZER {{ 'R','T','P','S' }}
 #if PLATFORM_IS_LITTLE_ENDIAN
 #define NN_PROTOCOLID_AS_UINT32 (((uint32_t)'R' << 0) | ((uint32_t)'T' << 8) | ((uint32_t)'P' << 16) | ((uint32_t)'S' << 24))
 #else
 #define NN_PROTOCOLID_AS_UINT32 (((uint32_t)'R' << 24) | ((uint32_t)'T' << 16) | ((uint32_t)'P' << 8) | ((uint32_t)'S' << 0))
 #endif
-#define NN_PROTOCOL_VERSION_INITIALIZER { RTPS_MAJOR, RTPS_MINOR }
-#define NN_VENDORID_INITIALIER MY_VENDOR_ID
-#define NN_HEADER_INITIALIZER { NN_PROTOCOLID_INITIALIZER, NN_PROTOCOL_VERSION_INITIALIZER, NN_VENDORID_INITIALIER, NN_GUID_PREFIX_UNKNOWN_INITIALIZER }
 #define RTPS_MESSAGE_HEADER_SIZE (sizeof (Header_t))
 
 typedef struct SubmessageHeader {
diff --git a/src/core/ddsi/include/ddsi/q_rtps.h b/src/core/ddsi/include/ddsi/q_rtps.h
index eea7cf9..561e284 100644
--- a/src/core/ddsi/include/ddsi/q_rtps.h
+++ b/src/core/ddsi/include/ddsi/q_rtps.h
@@ -13,16 +13,14 @@
 #define NN_RTPS_H
 
 #include "os/os_defs.h"
+#include "ddsi/ddsi_vendor.h"
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 typedef struct {
-  unsigned char id[2];
-} nn_vendorid_t;
-typedef struct {
-  unsigned char major, minor;
+  uint8_t major, minor;
 } nn_protocol_version_t;
 typedef union nn_guid_prefix {
   unsigned char s[12];
diff --git a/src/core/ddsi/src/ddsi_vendor.c b/src/core/ddsi/src/ddsi_vendor.c
new file mode 100644
index 0000000..ddde0fd
--- /dev/null
+++ b/src/core/ddsi/src/ddsi_vendor.c
@@ -0,0 +1,24 @@
+/*
+ * Copyright(c) 2019 ADLINK Technology Limited and others
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0, or the Eclipse Distribution License
+ * v. 1.0 which is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
+ */
+#include <string.h>
+
+#include "ddsi/ddsi_vendor.h"
+
+extern inline bool vendor_equals (nn_vendorid_t a, nn_vendorid_t b);
+extern inline bool vendor_is_rti (nn_vendorid_t vendor);
+extern inline bool vendor_is_twinoaks (nn_vendorid_t vendor);
+extern inline bool vendor_is_prismtech (nn_vendorid_t vendor);
+extern inline bool vendor_is_opensplice (nn_vendorid_t vendor);
+extern inline bool vendor_is_cloud (nn_vendorid_t vendor);
+extern inline bool vendor_is_eclipse (nn_vendorid_t vendor);
+extern inline bool vendor_is_eclipse_or_opensplice (nn_vendorid_t vendor);
+extern inline bool vendor_is_eclipse_or_prismtech (nn_vendorid_t vendor);
diff --git a/src/core/ddsi/src/q_ddsi_discovery.c b/src/core/ddsi/src/q_ddsi_discovery.c
index d596422..f089142 100644
--- a/src/core/ddsi/src/q_ddsi_discovery.c
+++ b/src/core/ddsi/src/q_ddsi_discovery.c
@@ -41,8 +41,6 @@
 #include "ddsi/q_md5.h"
 #include "ddsi/q_feature_check.h"
 
-static const nn_vendorid_t ownvendorid = MY_VENDOR_ID;
-
 static int get_locator (nn_locator_t *loc, const nn_locators_t *locs, int uc_same_subnet)
 {
   struct nn_locators_one *l;
@@ -182,7 +180,6 @@ static int write_mpayload (struct writer *wr, int alive, nn_parameterid_t keypar
 
 int spdp_write (struct participant *pp)
 {
-  static const nn_vendorid_t myvendorid = MY_VENDOR_ID;
   struct nn_xmsg *mpayload;
   struct nn_locators_one def_uni_loc_one, def_multi_loc_one, meta_uni_loc_one, meta_multi_loc_one;
   nn_plist_t ps;
@@ -220,7 +217,7 @@ int spdp_write (struct participant *pp)
   ps.builtin_endpoint_set = pp->bes;
   ps.protocol_version.major = RTPS_MAJOR;
   ps.protocol_version.minor = RTPS_MINOR;
-  ps.vendorid = myvendorid;
+  ps.vendorid = NN_VENDORID_ECLIPSE;
   if (pp->prismtech_bes)
   {
     ps.present |= PP_PRISMTECH_BUILTIN_ENDPOINT_SET;
@@ -460,7 +457,7 @@ static struct proxy_participant *find_ddsi2_proxy_participant (const nn_guid_t *
   ephash_enum_proxy_participant_init (&it);
   while ((pp = ephash_enum_proxy_participant_next (&it)) != NULL)
   {
-    if (vendor_is_opensplice (pp->vendor) && pp->e.guid.prefix.u[0] == ppguid->prefix.u[0] && pp->is_ddsi2_pp)
+    if (vendor_is_eclipse_or_opensplice (pp->vendor) && pp->e.guid.prefix.u[0] == ppguid->prefix.u[0] && pp->is_ddsi2_pp)
       break;
   }
   ephash_enum_proxy_participant_fini (&it);
@@ -478,7 +475,7 @@ static void make_participants_dependent_on_ddsi2 (const nn_guid_t *ddsi2guid, nn
   ephash_enum_proxy_participant_init (&it);
   while ((pp = ephash_enum_proxy_participant_next (&it)) != NULL)
   {
-    if (vendor_is_opensplice (pp->vendor) && pp->e.guid.prefix.u[0] == ddsi2guid->prefix.u[0] && !pp->is_ddsi2_pp)
+    if (vendor_is_eclipse_or_opensplice (pp->vendor) && pp->e.guid.prefix.u[0] == ddsi2guid->prefix.u[0] && !pp->is_ddsi2_pp)
     {
       DDS_TRACE("proxy participant %x:%x:%x:%x depends on ddsi2 %x:%x:%x:%x", PGUID (pp->e.guid), PGUID (*ddsi2guid));
       os_mutexLock (&pp->e.lock);
@@ -647,7 +644,7 @@ static int handle_SPDP_alive (const struct receiver_state *rst, nn_wctime_t time
        until the "privileged" one expires anyway */
     lease_duration = nn_to_ddsi_duration (T_NEVER);
   }
-  else if (vendor_is_opensplice (rst->vendor) && !(custom_flags & CF_PARTICIPANT_IS_DDSI2))
+  else if (vendor_is_eclipse_or_opensplice (rst->vendor) && !(custom_flags & CF_PARTICIPANT_IS_DDSI2))
   {
     /* Non-DDSI2 participants are made dependent on DDSI2 (but DDSI2
        itself need not be discovered yet) */
@@ -868,7 +865,6 @@ static int sedp_write_endpoint
    const nn_xqos_t *xqos, struct addrset *as)
 {
   const nn_xqos_t *defqos = is_writer_entityid (epguid->entityid) ? &gv.default_xqos_wr : &gv.default_xqos_rd;
-  const nn_vendorid_t my_vendor_id = MY_VENDOR_ID;
   struct nn_xmsg *mpayload;
   uint64_t qosdiff;
   nn_plist_t ps;
@@ -898,7 +894,7 @@ static int sedp_write_endpoint
     ps.present |= PP_PROTOCOL_VERSION | PP_VENDORID;
     ps.protocol_version.major = RTPS_MAJOR;
     ps.protocol_version.minor = RTPS_MINOR;
-    ps.vendorid = my_vendor_id;
+    ps.vendorid = NN_VENDORID_ECLIPSE;
 
     if (epcommon->group_guid.entityid.u != 0)
     {
@@ -959,7 +955,7 @@ static struct writer *get_sedp_writer (const struct participant *pp, unsigned en
 
 int sedp_write_writer (struct writer *wr)
 {
-  if ((!is_builtin_entityid(wr->e.guid.entityid, ownvendorid)) && (!wr->e.onlylocal))
+  if ((!is_builtin_entityid(wr->e.guid.entityid, NN_VENDORID_ECLIPSE)) && (!wr->e.onlylocal))
   {
     struct writer *sedp_wr = get_sedp_writer (wr->c.pp, NN_ENTITYID_SEDP_BUILTIN_PUBLICATIONS_WRITER);
 #ifdef DDSI_INCLUDE_SSM
@@ -974,7 +970,7 @@ int sedp_write_writer (struct writer *wr)
 
 int sedp_write_reader (struct reader *rd)
 {
-  if ((!is_builtin_entityid (rd->e.guid.entityid, ownvendorid)) && (!rd->e.onlylocal))
+  if ((!is_builtin_entityid (rd->e.guid.entityid, NN_VENDORID_ECLIPSE)) && (!rd->e.onlylocal))
   {
     struct writer *sedp_wr = get_sedp_writer (rd->c.pp, NN_ENTITYID_SEDP_BUILTIN_SUBSCRIPTIONS_WRITER);
 #ifdef DDSI_INCLUDE_NETWORK_PARTITIONS
@@ -989,7 +985,7 @@ int sedp_write_reader (struct reader *rd)
 
 int sedp_dispose_unregister_writer (struct writer *wr)
 {
-  if ((!is_builtin_entityid(wr->e.guid.entityid, ownvendorid)) && (!wr->e.onlylocal))
+  if ((!is_builtin_entityid(wr->e.guid.entityid, NN_VENDORID_ECLIPSE)) && (!wr->e.onlylocal))
   {
     struct writer *sedp_wr = get_sedp_writer (wr->c.pp, NN_ENTITYID_SEDP_BUILTIN_PUBLICATIONS_WRITER);
     return sedp_write_endpoint (sedp_wr, 0, &wr->e.guid, NULL, NULL, NULL, NULL);
@@ -999,7 +995,7 @@ int sedp_dispose_unregister_writer (struct writer *wr)
 
 int sedp_dispose_unregister_reader (struct reader *rd)
 {
-  if ((!is_builtin_entityid(rd->e.guid.entityid, ownvendorid)) && (!rd->e.onlylocal))
+  if ((!is_builtin_entityid(rd->e.guid.entityid, NN_VENDORID_ECLIPSE)) && (!rd->e.onlylocal))
   {
     struct writer *sedp_wr = get_sedp_writer (rd->c.pp, NN_ENTITYID_SEDP_BUILTIN_SUBSCRIPTIONS_WRITER);
     return sedp_write_endpoint (sedp_wr, 0, &rd->e.guid, NULL, NULL, NULL, NULL);
@@ -1058,7 +1054,7 @@ static struct proxy_participant *implicitly_create_proxypp (const nn_guid_t *ppg
     actual_vendorid = (datap->present & PP_VENDORID) ?  datap->vendorid : vendorid;
     new_proxy_participant(ppguid, 0, 0, &privguid, new_addrset(), new_addrset(), &pp_plist, T_NEVER, actual_vendorid, CF_IMPLICITLY_CREATED_PROXYPP, timestamp);
   }
-  else if (ppguid->prefix.u[0] == src_guid_prefix->u[0] && vendor_is_opensplice (vendorid))
+  else if (ppguid->prefix.u[0] == src_guid_prefix->u[0] && vendor_is_eclipse_or_opensplice (vendorid))
   {
     /* FIXME: requires address sets to be those of ddsi2, no built-in
        readers or writers, only if remote ddsi2 is provably running
@@ -1148,7 +1144,7 @@ static void handle_SEDP_alive (const struct receiver_state *rst, nn_plist_t *dat
   is_writer = is_writer_entityid (datap->endpoint_guid.entityid);
   if (!is_writer)
     nn_xqos_mergein_missing (xqos, &gv.default_xqos_rd);
-  else if (vendor_is_prismtech(vendorid))
+  else if (vendor_is_eclipse_or_prismtech(vendorid))
     nn_xqos_mergein_missing (xqos, &gv.default_xqos_wr);
   else
     nn_xqos_mergein_missing (xqos, &gv.default_xqos_wr_nad);
@@ -1251,7 +1247,7 @@ static void handle_SEDP_alive (const struct receiver_state *rst, nn_plist_t *dat
   nn_log_xqos(DDS_LC_DISCOVERY, xqos);
   DDS_LOG(DDS_LC_DISCOVERY, "}\n");
 
-  if ((datap->endpoint_guid.entityid.u & NN_ENTITYID_SOURCE_MASK) == NN_ENTITYID_SOURCE_VENDOR && !vendor_is_prismtech (vendorid))
+  if ((datap->endpoint_guid.entityid.u & NN_ENTITYID_SOURCE_MASK) == NN_ENTITYID_SOURCE_VENDOR && !vendor_is_eclipse_or_prismtech (vendorid))
   {
     DDS_LOG(DDS_LC_DISCOVERY, "ignoring vendor-specific endpoint %x:%x:%x:%x\n", PGUID (datap->endpoint_guid));
   }
diff --git a/src/core/ddsi/src/q_entity.c b/src/core/ddsi/src/q_entity.c
index c78c486..755389b 100644
--- a/src/core/ddsi/src/q_entity.c
+++ b/src/core/ddsi/src/q_entity.c
@@ -53,7 +53,6 @@ struct deleted_participant {
 
 static os_mutex deleted_participants_lock;
 static ut_avlTree_t deleted_participants;
-static const nn_vendorid_t ownvendorid = MY_VENDOR_ID;
 
 static int compare_guid (const void *va, const void *vb);
 static void augment_wr_prd_match (void *vnode, const void *vleft, const void *vright);
@@ -140,7 +139,7 @@ int is_builtin_entityid (nn_entityid_t id, nn_vendorid_t vendorid)
     return 1;
   else if ((id.u & NN_ENTITYID_SOURCE_MASK) != NN_ENTITYID_SOURCE_VENDOR)
     return 0;
-  else if (!vendor_is_prismtech (vendorid))
+  else if (!vendor_is_eclipse_or_prismtech (vendorid))
     return 0;
   else
   {
@@ -157,7 +156,7 @@ int is_builtin_endpoint (nn_entityid_t id, nn_vendorid_t vendorid)
 bool is_local_orphan_endpoint (const struct entity_common *e)
 {
   return (e->guid.prefix.u[0] == 0 && e->guid.prefix.u[1] == 0 && e->guid.prefix.u[2] == 0 &&
-          is_builtin_endpoint (e->guid.entityid, ownvendorid));
+          is_builtin_endpoint (e->guid.entityid, NN_VENDORID_ECLIPSE));
 }
 
 static void entity_common_init (struct entity_common *e, const struct nn_guid *guid, const char *name, enum entity_kind kind, nn_wctime_t tcreate, nn_vendorid_t vendorid, bool onlylocal)
@@ -247,7 +246,7 @@ nn_vendorid_t get_entity_vendorid (const struct entity_common *e)
     case EK_PARTICIPANT:
     case EK_READER:
     case EK_WRITER:
-      return (nn_vendorid_t) MY_VENDOR_ID;
+      return NN_VENDORID_ECLIPSE;
     case EK_PROXY_PARTICIPANT:
       return ((const struct proxy_participant *) e)->vendor;
     case EK_PROXY_READER:
@@ -256,7 +255,7 @@ nn_vendorid_t get_entity_vendorid (const struct entity_common *e)
       return ((const struct proxy_writer *) e)->c.vendor;
   }
   assert (0);
-  return (nn_vendorid_t) NN_VENDORID_UNKNOWN;
+  return NN_VENDORID_UNKNOWN;
 }
 
 /* DELETED PARTICIPANTS --------------------------------------------- */
@@ -437,7 +436,7 @@ int new_participant_guid (const nn_guid_t *ppguid, unsigned flags, const nn_plis
 
   pp = os_malloc (sizeof (*pp));
 
-  entity_common_init (&pp->e, ppguid, "", EK_PARTICIPANT, now (), ownvendorid, ((flags & RTPS_PF_ONLY_LOCAL) != 0));
+  entity_common_init (&pp->e, ppguid, "", EK_PARTICIPANT, now (), NN_VENDORID_ECLIPSE, ((flags & RTPS_PF_ONLY_LOCAL) != 0));
   pp->user_refc = 1;
   pp->builtin_refc = 0;
   pp->builtins_deleted = 0;
@@ -669,7 +668,7 @@ static void delete_builtin_endpoint (const struct nn_guid *ppguid, unsigned enti
   nn_guid_t guid;
   guid.prefix = ppguid->prefix;
   guid.entityid.u = entityid;
-  assert (is_builtin_entityid (to_entityid (entityid), ownvendorid));
+  assert (is_builtin_entityid (to_entityid (entityid), NN_VENDORID_ECLIPSE));
   if (is_writer_entityid (to_entityid (entityid)))
     delete_writer_nolinger (&guid);
   else
@@ -680,7 +679,7 @@ static struct participant *ref_participant (struct participant *pp, const struct
 {
   nn_guid_t stguid;
   os_mutexLock (&pp->refc_lock);
-  if (guid_of_refing_entity && is_builtin_endpoint (guid_of_refing_entity->entityid, ownvendorid))
+  if (guid_of_refing_entity && is_builtin_endpoint (guid_of_refing_entity->entityid, NN_VENDORID_ECLIPSE))
     pp->builtin_refc++;
   else
     pp->user_refc++;
@@ -719,7 +718,7 @@ static void unref_participant (struct participant *pp, const struct nn_guid *gui
   nn_guid_t stguid;
 
   os_mutexLock (&pp->refc_lock);
-  if (guid_of_refing_entity && is_builtin_endpoint (guid_of_refing_entity->entityid, ownvendorid))
+  if (guid_of_refing_entity && is_builtin_endpoint (guid_of_refing_entity->entityid, NN_VENDORID_ECLIPSE))
     pp->builtin_refc--;
   else
     pp->user_refc--;
@@ -1817,7 +1816,7 @@ static void proxy_writer_add_connection (struct proxy_writer *pwr, struct reader
   {
     m->in_sync = PRMSS_SYNC;
   }
-  else if (!config.conservative_builtin_reader_startup && is_builtin_entityid (rd->e.guid.entityid, ownvendorid) && !ut_avlIsEmpty (&pwr->readers))
+  else if (!config.conservative_builtin_reader_startup && is_builtin_entityid (rd->e.guid.entityid, NN_VENDORID_ECLIPSE) && !ut_avlIsEmpty (&pwr->readers))
   {
     /* builtins really don't care about multiple copies */
     m->in_sync = PRMSS_SYNC;
@@ -2023,7 +2022,7 @@ static void reader_qos_mismatch (struct reader * rd, uint32_t reason)
 
 static void connect_writer_with_proxy_reader (struct writer *wr, struct proxy_reader *prd, nn_mtime_t tnow)
 {
-  const int isb0 = (is_builtin_entityid (wr->e.guid.entityid, ownvendorid) != 0);
+  const int isb0 = (is_builtin_entityid (wr->e.guid.entityid, NN_VENDORID_ECLIPSE) != 0);
   const int isb1 = (is_builtin_entityid (prd->e.guid.entityid, prd->c.vendor) != 0);
   int32_t reason;
   OS_UNUSED_ARG(tnow);
@@ -2043,7 +2042,7 @@ static void connect_writer_with_proxy_reader (struct writer *wr, struct proxy_re
 static void connect_proxy_writer_with_reader (struct proxy_writer *pwr, struct reader *rd, nn_mtime_t tnow)
 {
   const int isb0 = (is_builtin_entityid (pwr->e.guid.entityid, pwr->c.vendor) != 0);
-  const int isb1 = (is_builtin_entityid (rd->e.guid.entityid, ownvendorid) != 0);
+  const int isb1 = (is_builtin_entityid (rd->e.guid.entityid, NN_VENDORID_ECLIPSE) != 0);
   int32_t reason;
   nn_count_t init_count;
   if (isb0 != isb1)
@@ -2063,7 +2062,7 @@ static void connect_writer_with_reader (struct writer *wr, struct reader *rd, nn
 {
   int32_t reason;
   (void)tnow;
-  if (!is_local_orphan_endpoint (&wr->e) && (is_builtin_entityid (wr->e.guid.entityid, ownvendorid) || is_builtin_entityid (rd->e.guid.entityid, ownvendorid)))
+  if (!is_local_orphan_endpoint (&wr->e) && (is_builtin_entityid (wr->e.guid.entityid, NN_VENDORID_ECLIPSE) || is_builtin_entityid (rd->e.guid.entityid, NN_VENDORID_ECLIPSE)))
     return;
   if ((reason = qos_match_p (rd->xqos, wr->xqos)) >= 0)
   {
@@ -2231,7 +2230,7 @@ static void generic_do_match (struct entity_common *e, nn_mtime_t tnow)
   struct ephash_enum est;
   struct entity_common *em;
   enum entity_kind mkind = generic_do_match_mkind(e->kind);
-  if (!is_builtin_entityid (e->guid.entityid, ownvendorid))
+  if (!is_builtin_entityid (e->guid.entityid, NN_VENDORID_ECLIPSE))
   {
     DDS_LOG(DDS_LC_DISCOVERY, "match_%s_with_%ss(%s %x:%x:%x:%x) scanning all %ss\n",
             generic_do_match_kindstr_us (e->kind), generic_do_match_kindstr_us (mkind),
@@ -2281,7 +2280,7 @@ static void generic_do_local_match (struct entity_common *e, nn_mtime_t tnow)
   struct ephash_enum est;
   struct entity_common *em;
   enum entity_kind mkind;
-  if (is_builtin_entityid (e->guid.entityid, ownvendorid) && !is_local_orphan_endpoint (e))
+  if (is_builtin_entityid (e->guid.entityid, NN_VENDORID_ECLIPSE) && !is_local_orphan_endpoint (e))
     /* never a need for local matches on discovery endpoints */
     return;
   mkind = generic_do_local_match_mkind(e->kind);
@@ -2338,8 +2337,8 @@ static void new_reader_writer_common (const struct nn_guid *guid, const struct d
 {
   const char *partition = "(default)";
   const char *partition_suffix = "";
-  assert (is_builtin_entityid (guid->entityid, ownvendorid) ? (topic == NULL) : (topic != NULL));
-  if (is_builtin_entityid (guid->entityid, ownvendorid))
+  assert (is_builtin_entityid (guid->entityid, NN_VENDORID_ECLIPSE) ? (topic == NULL) : (topic != NULL));
+  if (is_builtin_entityid (guid->entityid, NN_VENDORID_ECLIPSE))
   {
     /* continue printing it as not being in a partition, the actual
        value doesn't matter because it is never matched based on QoS
@@ -2362,7 +2361,7 @@ static void new_reader_writer_common (const struct nn_guid *guid, const struct d
 
 static void endpoint_common_init (struct entity_common *e, struct endpoint_common *c, enum entity_kind kind, const struct nn_guid *guid, const struct nn_guid *group_guid, struct participant *pp)
 {
-  entity_common_init (e, guid, NULL, kind, now (), ownvendorid, pp->e.onlylocal);
+  entity_common_init (e, guid, NULL, kind, now (), NN_VENDORID_ECLIPSE, pp->e.onlylocal);
   c->pp = ref_participant (pp, &e->guid);
   if (group_guid)
     c->group_guid = *group_guid;
@@ -2372,7 +2371,7 @@ static void endpoint_common_init (struct entity_common *e, struct endpoint_commo
 
 static void endpoint_common_fini (struct entity_common *e, struct endpoint_common *c)
 {
-  if (!is_builtin_entityid(e->guid.entityid, ownvendorid))
+  if (!is_builtin_entityid(e->guid.entityid, NN_VENDORID_ECLIPSE))
     pp_release_entityid(c->pp, e->guid.entityid);
   if (c->pp)
     unref_participant (c->pp, &e->guid);
@@ -2627,7 +2626,7 @@ static void new_writer_guid_common_init (struct writer *wr, const struct ddsi_se
   assert (wr->xqos->present & QP_RELIABILITY);
   wr->reliable = (wr->xqos->reliability.kind != NN_BEST_EFFORT_RELIABILITY_QOS);
   assert (wr->xqos->present & QP_DURABILITY);
-  if (is_builtin_entityid (wr->e.guid.entityid, ownvendorid))
+  if (is_builtin_entityid (wr->e.guid.entityid, NN_VENDORID_ECLIPSE))
   {
     assert (wr->xqos->history.kind == NN_KEEP_LAST_HISTORY_QOS);
     assert (wr->xqos->durability.kind == NN_TRANSIENT_LOCAL_DURABILITY_QOS);
@@ -2771,7 +2770,7 @@ static void new_writer_guid_common_init (struct writer *wr, const struct ddsi_se
     wr->whc_low = config.whc_lowwater_mark;
     wr->whc_high = config.whc_init_highwater_mark.value;
   }
-  assert (!is_builtin_entityid(wr->e.guid.entityid, ownvendorid) || (wr->whc_low == wr->whc_high && wr->whc_low == INT32_MAX));
+  assert (!is_builtin_entityid(wr->e.guid.entityid, NN_VENDORID_ECLIPSE) || (wr->whc_low == wr->whc_high && wr->whc_low == INT32_MAX));
 
   /* Connection admin */
   ut_avlInit (&wr_readers_treedef, &wr->readers);
@@ -2859,7 +2858,7 @@ struct local_orphan_writer *new_local_orphan_writer (nn_entityid_t entityid, str
 
   memset (&guid.prefix, 0, sizeof (guid.prefix));
   guid.entityid = entityid;
-  entity_common_init (&wr->e, &guid, NULL, EK_WRITER, now (), ownvendorid, true);
+  entity_common_init (&wr->e, &guid, NULL, EK_WRITER, now (), NN_VENDORID_ECLIPSE, true);
   wr->c.pp = NULL;
   memset (&wr->c.group_guid, 0, sizeof (wr->c.group_guid));
   new_writer_guid_common_init (wr, topic, xqos, whc, 0, NULL);
@@ -2905,7 +2904,7 @@ static void gc_delete_writer (struct gcreq *gcreq)
   }
 
   /* Do last gasp on SEDP and free writer. */
-  if (!is_builtin_entityid (wr->e.guid.entityid, ownvendorid))
+  if (!is_builtin_entityid (wr->e.guid.entityid, NN_VENDORID_ECLIPSE))
     sedp_dispose_unregister_writer (wr);
   if (wr->status_cb)
   {
@@ -3223,7 +3222,7 @@ static struct reader * new_reader_guid
 #endif
   if (topic == NULL)
   {
-    assert (is_builtin_entityid (rd->e.guid.entityid, ownvendorid));
+    assert (is_builtin_entityid (rd->e.guid.entityid, NN_VENDORID_ECLIPSE));
   }
   rd->status_cb = status_cb;
   rd->status_cb_entity = status_entity;
@@ -3353,7 +3352,7 @@ static void gc_delete_reader (struct gcreq *gcreq)
     free_rd_wr_match (m);
   }
 
-  if (!is_builtin_entityid (rd->e.guid.entityid, ownvendorid))
+  if (!is_builtin_entityid (rd->e.guid.entityid, NN_VENDORID_ECLIPSE))
     sedp_dispose_unregister_reader (rd);
 #ifdef DDSI_INCLUDE_NETWORK_PARTITIONS
   addrset_forall (rd->as, leave_mcast_helper, gv.data_conn_mc);
@@ -3542,7 +3541,7 @@ void new_proxy_participant
   /* Non-PrismTech doesn't implement the PT extensions and therefore won't generate
      a CMParticipant; if a PT peer does not implement a CMParticipant writer, then it
      presumably also is a handicapped implementation (perhaps simply an old one) */
-  if (!vendor_is_prismtech(proxypp->vendor) ||
+  if (!vendor_is_eclipse_or_prismtech(proxypp->vendor) ||
       (proxypp->bes != 0 && !(proxypp->prismtech_bes & NN_DISC_BUILTIN_ENDPOINT_CM_PARTICIPANT_WRITER)))
     proxypp->proxypp_have_cm = 1;
   else
diff --git a/src/core/ddsi/src/q_init.c b/src/core/ddsi/src/q_init.c
index 4baddd2..892369d 100644
--- a/src/core/ddsi/src/q_init.c
+++ b/src/core/ddsi/src/q_init.c
@@ -1499,7 +1499,6 @@ void rtps_stop (void)
   }
 
   {
-    const nn_vendorid_t ownvendorid = MY_VENDOR_ID;
     struct ephash_enum_writer est_wr;
     struct ephash_enum_reader est_rd;
     struct ephash_enum_participant est_pp;
@@ -1515,7 +1514,7 @@ void rtps_stop (void)
     ephash_enum_writer_init (&est_wr);
     while ((wr = ephash_enum_writer_next (&est_wr)) != NULL)
     {
-      if (!is_builtin_entityid (wr->e.guid.entityid, ownvendorid))
+      if (!is_builtin_entityid (wr->e.guid.entityid, NN_VENDORID_ECLIPSE))
         delete_writer_nolinger (&wr->e.guid);
     }
     ephash_enum_writer_fini (&est_wr);
@@ -1523,7 +1522,7 @@ void rtps_stop (void)
     ephash_enum_reader_init (&est_rd);
     while ((rd = ephash_enum_reader_next (&est_rd)) != NULL)
     {
-      if (!is_builtin_entityid (rd->e.guid.entityid, ownvendorid))
+      if (!is_builtin_entityid (rd->e.guid.entityid, NN_VENDORID_ECLIPSE))
         (void)delete_reader (&rd->e.guid);
     }
     ephash_enum_reader_fini (&est_rd);
diff --git a/src/core/ddsi/src/q_misc.c b/src/core/ddsi/src/q_misc.c
index a689c5a..2412962 100644
--- a/src/core/ddsi/src/q_misc.c
+++ b/src/core/ddsi/src/q_misc.c
@@ -15,71 +15,8 @@
 #include "ddsi/q_bswap.h"
 #include "ddsi/q_md5.h"
 
-int vendor_is_rti (nn_vendorid_t vendor)
-{
-  const nn_vendorid_t rti = NN_VENDORID_RTI;
-  return vendor.id[0] == rti.id[0] && vendor.id[1] == rti.id[1];
-}
-
-int vendor_is_twinoaks (nn_vendorid_t vendor)
-{
-  const nn_vendorid_t twinoaks = NN_VENDORID_TWINOAKS;
-  return vendor.id[0] == twinoaks.id[0] && vendor.id[1] == twinoaks.id[1];
-}
-
-int vendor_is_cloud (nn_vendorid_t vendor)
-{
-  const nn_vendorid_t cloud = NN_VENDORID_PRISMTECH_CLOUD;
-  return vendor.id[0] == cloud.id[0] && vendor.id[1] == cloud.id[1];
-}
-
-int vendor_is_prismtech (nn_vendorid_t vid)
-{
-  const nn_vendorid_t pt1 = NN_VENDORID_PRISMTECH_OSPL;
-  const nn_vendorid_t pt2 = NN_VENDORID_PRISMTECH_LITE;
-  const nn_vendorid_t pt3 = NN_VENDORID_PRISMTECH_GATEWAY;
-  const nn_vendorid_t pt4 = NN_VENDORID_PRISMTECH_JAVA;
-  const nn_vendorid_t pt5 = NN_VENDORID_PRISMTECH_CLOUD;
-  const nn_vendorid_t pt6 = NN_VENDORID_ECLIPSE_CYCLONEDDS;
-
-  return
-    (vid.id[0] == pt1.id[0]) &&
-    ((vid.id[1] == pt1.id[1]) || (vid.id[1] == pt2.id[1])
-     || (vid.id[1] == pt3.id[1]) || (vid.id[1] == pt4.id[1])
-     || (vid.id[1] == pt5.id[1]) || (vid.id[1] == pt6.id[1]));
-}
-
-int vendor_is_opensplice (nn_vendorid_t vid)
-{
-  const nn_vendorid_t pt1 = NN_VENDORID_PRISMTECH_OSPL;
-  return (vid.id[0] == pt1.id[0] && vid.id[1] == pt1.id[1]);
-}
-
-int vendor_is_lite (nn_vendorid_t vid)
-{
-  const nn_vendorid_t pt1 = NN_VENDORID_PRISMTECH_LITE;
-  return (vid.id[0] == pt1.id[0] && vid.id[1] == pt1.id[1]);
-}
-
-int is_own_vendor (nn_vendorid_t vendor)
-{
-  const nn_vendorid_t ownid = MY_VENDOR_ID;
-  return vendor.id[0] == ownid.id[0] && vendor.id[1] == ownid.id[1];
-}
-
-
-seqno_t fromSN (const nn_sequence_number_t sn)
-{
-  return ((seqno_t) sn.high << 32) | sn.low;
-}
-
-nn_sequence_number_t toSN (seqno_t n)
-{
-  nn_sequence_number_t x;
-  x.high = (int) (n >> 32);
-  x.low = (unsigned) n;
-  return x;
-}
+extern inline seqno_t fromSN (const nn_sequence_number_t sn);
+extern inline nn_sequence_number_t toSN (seqno_t n);
 
 #ifdef DDSI_INCLUDE_NETWORK_PARTITIONS
 int WildcardOverlap(char * p1, char * p2)
diff --git a/src/core/ddsi/src/q_plist.c b/src/core/ddsi/src/q_plist.c
index 87938f0..f5277b8 100644
--- a/src/core/ddsi/src/q_plist.c
+++ b/src/core/ddsi/src/q_plist.c
@@ -82,8 +82,7 @@ static size_t align4u (size_t x)
 
 static int protocol_version_is_newer (nn_protocol_version_t pv)
 {
-  const nn_protocol_version_t mv = NN_PROTOCOL_VERSION_INITIALIZER;
-  return (pv.major < mv.major) ? 0 : (pv.major > mv.major) ? 1 : (pv.minor > mv.minor);
+  return (pv.major < RTPS_MAJOR) ? 0 : (pv.major > RTPS_MAJOR) ? 1 : (pv.minor > RTPS_MINOR);
 }
 
 static int validate_string (const struct dd *dd, size_t *len)
@@ -1819,10 +1818,7 @@ static int valid_endpoint_guid (const nn_guid_t *g, const struct dd *dd)
           }
       }
     case NN_ENTITYID_SOURCE_VENDOR:
-      /* vendor specific: always ok, unless vendor is PrismTech, 'cos
-         we don't do that! (FIXME, might be worthwhile to be less
-         strict, or add an implementation version number here) */
-      if (!is_own_vendor (dd->vendorid) || protocol_version_is_newer (dd->protocol_version))
+      if (!vendor_is_eclipse (dd->vendorid))
         return 0;
       else
       {
@@ -1840,7 +1836,7 @@ static int valid_endpoint_guid (const nn_guid_t *g, const struct dd *dd)
               return 0;
             else
             {
-              DDS_TRACE("plist/valid_endpoint_guid[src=VENDOR,proto=%u.%u]: invalid entityid (%x)\n",
+              DDS_TRACE("plist/valid_endpoint_guid[src=VENDOR,proto=%u.%u]: unexpected entityid (%x)\n",
                       dd->protocol_version.major, dd->protocol_version.minor, g->entityid.u);
               return 0;
             }
@@ -1891,7 +1887,7 @@ static void bswap_prismtech_participant_version_info (nn_prismtech_participant_v
 
 static int do_prismtech_participant_version_info (nn_prismtech_participant_version_info_t *pvi, uint64_t *present, uint64_t *aliased, const struct dd *dd)
 {
-  if (!vendor_is_prismtech (dd->vendorid))
+  if (!vendor_is_eclipse_or_prismtech (dd->vendorid))
     return 0;
   else if (dd->bufsz < NN_PRISMTECH_PARTICIPANT_VERSION_INFO_FIXED_CDRSIZE)
   {
@@ -2230,7 +2226,7 @@ static int init_one_parameter
     case PID_PRISMTECH_READER_DATA_LIFECYCLE: /* PrismTech specific */
       {
         int ret;
-        if (!vendor_is_prismtech (dd->vendorid))
+        if (!vendor_is_eclipse_or_prismtech (dd->vendorid))
           return 0;
         if (dd->bufsz >= sizeof (nn_reader_data_lifecycle_qospolicy_t))
           ret = do_reader_data_lifecycle_v1 (&dest->qos.reader_data_lifecycle, dd);
@@ -2246,7 +2242,7 @@ static int init_one_parameter
         return ret;
       }
     case PID_PRISMTECH_WRITER_DATA_LIFECYCLE: /* PrismTech specific */
-      if (!vendor_is_prismtech (dd->vendorid))
+      if (!vendor_is_eclipse_or_prismtech (dd->vendorid))
         return 0;
       else
       {
@@ -2288,7 +2284,7 @@ static int init_one_parameter
       }
 
     case PID_PRISMTECH_RELAXED_QOS_MATCHING:
-      if (!vendor_is_prismtech (dd->vendorid))
+      if (!vendor_is_eclipse_or_prismtech (dd->vendorid))
         return 0;
       else if (dd->bufsz < sizeof (dest->qos.relaxed_qos_matching))
       {
@@ -2309,7 +2305,7 @@ static int init_one_parameter
       }
 
     case PID_PRISMTECH_SYNCHRONOUS_ENDPOINT: /* PrismTech specific */
-      if (!vendor_is_prismtech (dd->vendorid))
+      if (!vendor_is_eclipse_or_prismtech (dd->vendorid))
         return 0;
       else if (dd->bufsz < sizeof (dest->qos.synchronous_endpoint))
       {
@@ -2492,7 +2488,7 @@ static int init_one_parameter
       return 0;
 
     case PID_PRISMTECH_BUILTIN_ENDPOINT_SET:
-      if (!vendor_is_prismtech (dd->vendorid))
+      if (!vendor_is_eclipse_or_prismtech (dd->vendorid))
         return 0;
       else if (dd->bufsz < sizeof (dest->prismtech_builtin_endpoint_set))
       {
@@ -2545,7 +2541,7 @@ static int init_one_parameter
       }
       /* Clear all bits we don't understand, then add the extended bits if present */
       dest->statusinfo &= NN_STATUSINFO_STANDARDIZED;
-      if (dd->bufsz >= 2 * sizeof (dest->statusinfo) && vendor_is_opensplice(dd->vendorid))
+      if (dd->bufsz >= 2 * sizeof (dest->statusinfo) && vendor_is_eclipse_or_opensplice(dd->vendorid))
       {
         uint32_t statusinfox;
         Q_STATIC_ASSERT_CODE (sizeof(statusinfox) == sizeof(dest->statusinfo));
@@ -2603,7 +2599,7 @@ static int init_one_parameter
       return do_guid (&dest->endpoint_guid, &dest->present, PP_ENDPOINT_GUID, valid_endpoint_guid, dd);
 
     case PID_PRISMTECH_ENDPOINT_GUID: /* case PID_RTI_TYPECODE: */
-      if (vendor_is_prismtech (dd->vendorid))
+      if (vendor_is_eclipse_or_prismtech (dd->vendorid))
       {
         /* PrismTech specific variant of ENDPOINT_GUID, for strict compliancy */
         return do_guid (&dest->endpoint_guid, &dest->present, PP_ENDPOINT_GUID, valid_endpoint_guid, dd);
@@ -2624,33 +2620,33 @@ static int init_one_parameter
       return do_prismtech_participant_version_info(&dest->prismtech_participant_version_info, &dest->present, &dest->aliased, dd);
 
     case PID_PRISMTECH_SUBSCRIPTION_KEYS:
-      if (!vendor_is_prismtech (dd->vendorid))
+      if (!vendor_is_eclipse_or_prismtech (dd->vendorid))
         return 0;
       return do_subscription_keys_qospolicy (&dest->qos.subscription_keys, &dest->qos.present, &dest->qos.aliased, QP_PRISMTECH_SUBSCRIPTION_KEYS, dd);
 
     case PID_PRISMTECH_READER_LIFESPAN:
-      if (!vendor_is_prismtech (dd->vendorid))
+      if (!vendor_is_eclipse_or_prismtech (dd->vendorid))
         return 0;
       return do_reader_lifespan_qospolicy (&dest->qos.reader_lifespan, &dest->qos.present, QP_PRISMTECH_READER_LIFESPAN, dd);
 
 
     case PID_PRISMTECH_ENTITY_FACTORY:
-      if (!vendor_is_prismtech (dd->vendorid))
+      if (!vendor_is_eclipse_or_prismtech (dd->vendorid))
         return 0;
       return do_entity_factory_qospolicy (&dest->qos.entity_factory, &dest->qos.present, QP_PRISMTECH_ENTITY_FACTORY, dd);
 
     case PID_PRISMTECH_NODE_NAME:
-      if (!vendor_is_prismtech (dd->vendorid))
+      if (!vendor_is_eclipse_or_prismtech (dd->vendorid))
         return 0;
       return do_string (&dest->node_name, &dest->present, &dest->aliased, pwanted, PP_PRISMTECH_NODE_NAME, dd);
 
     case PID_PRISMTECH_EXEC_NAME:
-      if (!vendor_is_prismtech (dd->vendorid))
+      if (!vendor_is_eclipse_or_prismtech (dd->vendorid))
         return 0;
       return do_string (&dest->exec_name, &dest->present, &dest->aliased, pwanted, PP_PRISMTECH_EXEC_NAME, dd);
 
     case PID_PRISMTECH_SERVICE_TYPE:
-      if (!vendor_is_prismtech (dd->vendorid))
+      if (!vendor_is_eclipse_or_prismtech (dd->vendorid))
         return 0;
       if (dd->bufsz < sizeof (dest->service_type))
       {
@@ -2664,7 +2660,7 @@ static int init_one_parameter
       return 0;
 
     case PID_PRISMTECH_PROCESS_ID:
-      if (!vendor_is_prismtech (dd->vendorid))
+      if (!vendor_is_eclipse_or_prismtech (dd->vendorid))
         return 0;
       if (dd->bufsz < sizeof (dest->process_id))
       {
@@ -2678,12 +2674,12 @@ static int init_one_parameter
       return 0;
 
     case PID_PRISMTECH_TYPE_DESCRIPTION:
-      if (!vendor_is_prismtech (dd->vendorid))
+      if (!vendor_is_eclipse_or_prismtech (dd->vendorid))
         return 0;
       return do_string (&dest->type_description, &dest->present, &dest->aliased, pwanted, PP_PRISMTECH_TYPE_DESCRIPTION, dd);
 
     case PID_PRISMTECH_EOTINFO:
-      if (!vendor_is_opensplice (dd->vendorid))
+      if (!vendor_is_eclipse_or_opensplice (dd->vendorid))
         return 0;
       else if (dd->bufsz < 2*sizeof (uint32_t))
       {
@@ -3135,7 +3131,7 @@ unsigned char *nn_plist_quickscan (struct nn_rsample_info *dest, const struct nn
         else
         {
           unsigned stinfo = fromBE4u (*((unsigned *) pl));
-          unsigned stinfox = (length < 8 || !vendor_is_opensplice(src->vendorid)) ? 0 : fromBE4u (*((unsigned *) pl + 1));
+          unsigned stinfox = (length < 8 || !vendor_is_eclipse_or_opensplice(src->vendorid)) ? 0 : fromBE4u (*((unsigned *) pl + 1));
 #if (NN_STATUSINFO_DISPOSE | NN_STATUSINFO_UNREGISTER) != 3
 #error "expected dispose/unregister to be in lowest 2 bits"
 #endif
diff --git a/src/core/ddsi/src/q_receive.c b/src/core/ddsi/src/q_receive.c
index 7a2cd8f..8ce3321 100644
--- a/src/core/ddsi/src/q_receive.c
+++ b/src/core/ddsi/src/q_receive.c
@@ -2837,7 +2837,7 @@ static int handle_submsg_sequence
         break;
 
       case SMID_PT_INFO_CONTAINER:
-        if (is_own_vendor (rst->vendor) || vendor_is_lite(rst->vendor))
+        if (vendor_is_eclipse_or_prismtech (rst->vendor))
         {
           state = "parse:pt_info_container";
           DDS_TRACE("PT_INFO_CONTAINER(");
@@ -2898,7 +2898,7 @@ static int handle_submsg_sequence
                rst->protocol_version.minor < RTPS_MINOR_MINIMUM))
             goto malformed;
         }
-        else if (is_own_vendor (rst->vendor))
+        else if (vendor_is_eclipse (rst->vendor))
         {
           /* One wouldn't expect undefined stuff from ourselves,
              except that we need to be up- and backwards compatible
diff --git a/src/core/ddsi/src/q_transmit.c b/src/core/ddsi/src/q_transmit.c
index 28ebdc9..4d81d84 100644
--- a/src/core/ddsi/src/q_transmit.c
+++ b/src/core/ddsi/src/q_transmit.c
@@ -953,13 +953,10 @@ static os_result throttle_writer (struct nn_xpack *xp, struct writer *wr)
   whc_get_state(wr->whc, &whcst);
 
   {
-#ifndef NDEBUG
-    nn_vendorid_t ownvendorid = MY_VENDOR_ID;
-#endif
     ASSERT_MUTEX_HELD (&wr->e.lock);
     assert (wr->throttling == 0);
     assert (vtime_awake_p (lookup_thread_state ()->vtime));
-    assert (!is_builtin_entityid(wr->e.guid.entityid, ownvendorid));
+    assert (!is_builtin_entityid(wr->e.guid.entityid, NN_VENDORID_ECLIPSE));
   }
 
   DDS_LOG(DDS_LC_THROTTLE, "writer %x:%x:%x:%x waiting for whc to shrink below low-water mark (whc %"PRIuSIZE" low=%u high=%u)\n", PGUID (wr->e.guid), whcst.unacked_bytes, wr->whc_low, wr->whc_high);
diff --git a/src/core/ddsi/src/q_xmsg.c b/src/core/ddsi/src/q_xmsg.c
index 5d1e95c..9946ed3 100644
--- a/src/core/ddsi/src/q_xmsg.c
+++ b/src/core/ddsi/src/q_xmsg.c
@@ -288,7 +288,6 @@ static void nn_xmsg_reinit (struct nn_xmsg *m, enum nn_xmsg_kind kind)
 
 static struct nn_xmsg *nn_xmsg_allocnew (struct nn_xmsgpool *pool, size_t expected_size, enum nn_xmsg_kind kind)
 {
-  const nn_vendorid_t myvendorid = MY_VENDOR_ID;
   struct nn_xmsg *m;
   struct nn_xmsg_data *d;
 
@@ -312,7 +311,7 @@ static struct nn_xmsg *nn_xmsg_allocnew (struct nn_xmsgpool *pool, size_t expect
   d->src.unused = 0;
   d->src.version.major = RTPS_MAJOR;
   d->src.version.minor = RTPS_MINOR;
-  d->src.vendorid = myvendorid;
+  d->src.vendorid = NN_VENDORID_ECLIPSE;
   d->dst.smhdr.submessageId = SMID_INFO_DST;
   d->dst.smhdr.flags = (PLATFORM_IS_LITTLE_ENDIAN ? SMFLAG_ENDIANNESS : 0);
   d->dst.smhdr.octetsToNextHeader = sizeof (d->dst.guid_prefix);
@@ -1239,7 +1238,6 @@ static void nn_xpack_reinit (struct nn_xpack *xp)
 
 struct nn_xpack * nn_xpack_new (ddsi_tran_conn_t conn, uint32_t bw_limit, bool async_mode)
 {
-  const nn_vendorid_t myvendorid = MY_VENDOR_ID;
   struct nn_xpack *xp;
 
   /* Disallow setting async_mode if not configured to enable async mode: this way we
@@ -1257,7 +1255,7 @@ struct nn_xpack * nn_xpack_new (ddsi_tran_conn_t conn, uint32_t bw_limit, bool a
   xp->hdr.protocol.id[3] = 'S';
   xp->hdr.version.major = RTPS_MAJOR;
   xp->hdr.version.minor = RTPS_MINOR;
-  xp->hdr.vendorid = myvendorid;
+  xp->hdr.vendorid = NN_VENDORID_ECLIPSE;
 
   /* MSG_LEN first sub message for stream based connections */