12 files changed, 161 insertions, 79 deletions

diff --git a/OpenSim/Framework/Servers/ServerBase.cs b/OpenSim/Framework/Servers/ServerBase.cs
index 1a867fd..07a09e6 100644
--- a/OpenSim/Framework/Servers/ServerBase.cs
+++ b/OpenSim/Framework/Servers/ServerBase.cs
@@ -873,8 +873,8 @@ namespace OpenSim.Framework.Servers
 
         protected string GetVersionText()
         {
-            return String.Format("Version: {0} (interface version {1}, SIMULATION/{2})", 
-                m_version, VersionInfo.MajorInterfaceVersion, VersionInfo.SimulationServiceVersion);
+            return String.Format("Version: {0} (SIMULATION/{1} - SIMULATION/{2})", 
+                m_version, VersionInfo.SimulationServiceVersionSupportedMin, VersionInfo.SimulationServiceVersionSupportedMax);
         }
 
         /// <summary>
@@ -1045,4 +1045,4 @@ namespace OpenSim.Framework.Servers
         /// </summary>
         protected virtual void ShutdownSpecific() {}
     }
-}
\ No newline at end of file
+}
diff --git a/OpenSim/Framework/VersionInfo.cs b/OpenSim/Framework/VersionInfo.cs
index 54c4508..a145d34 100644
--- a/OpenSim/Framework/VersionInfo.cs
+++ b/OpenSim/Framework/VersionInfo.cs
@@ -61,7 +61,9 @@ namespace OpenSim
         /// This is the external interface version.  It is separate from the OpenSimulator project version.
         /// 
         /// </value>
-        public readonly static int MajorInterfaceVersion = 8;
+        /// Commented because it's not used anymore, see below for new
+        /// versioning method.
+        //public readonly static int MajorInterfaceVersion = 8;
 
         /// <summary>
         /// This rules versioning regarding teleports, and compatibility between simulators in that regard.
@@ -80,6 +82,9 @@ namespace OpenSim
         /// "SIMULATION/0.1" 
         ///   - this is an older teleport protocol used in OpenSimulator 0.7.5 and before.
         /// </remarks>
-        public readonly static float SimulationServiceVersion = 0.3f;
+        public readonly static float SimulationServiceVersionAcceptedMin = 0.3f;
+        public readonly static float SimulationServiceVersionAcceptedMax = 0.4f;
+        public readonly static float SimulationServiceVersionSupportedMin = 0.3f;
+        public readonly static float SimulationServiceVersionSupportedMax = 0.4f;
     }
 }
diff --git a/OpenSim/Region/CoreModules/Framework/EntityTransfer/EntityTransferModule.cs b/OpenSim/Region/CoreModules/Framework/EntityTransfer/EntityTransferModule.cs
index 155a085..ab9f200 100644
--- a/OpenSim/Region/CoreModules/Framework/EntityTransfer/EntityTransferModule.cs
+++ b/OpenSim/Region/CoreModules/Framework/EntityTransfer/EntityTransferModule.cs
@@ -57,13 +57,6 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
         public const int DefaultMaxTransferDistance = 4095;
         public const bool WaitForAgentArrivedAtDestinationDefault = true;
 
-        public static readonly string OutgoingTransferVersionName = "SIMULATION";
-
-        /// <summary>
-        /// Determine the entity transfer version we will use for teleports.
-        /// </summary>
-        public static readonly float OutgoingTransferVersion = VersionInfo.SimulationServiceVersion;
-
         /// <summary>
         /// The maximum distance, in standard region units (256m) that an agent is allowed to transfer.
         /// </summary>
@@ -726,10 +719,9 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
                     sp.Name, sp.Scene.Name, finalDestination.RegionName);
 
             string reason;
-            string version;
-            string myversion = string.Format("{0}/{1}", OutgoingTransferVersionName, OutgoingTransferVersion);
+            float version;
             if (!Scene.SimulationService.QueryAccess(
-                finalDestination, sp.ControllingClient.AgentId, homeURI, true, position, myversion, sp.Scene.GetFormatsOffered(), out version, out reason))
+                finalDestination, sp.ControllingClient.AgentId, homeURI, true, position, sp.Scene.GetFormatsOffered(), out version, out reason))
             {
                 sp.ControllingClient.SendTeleportFailed(reason);
 
@@ -746,8 +738,8 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
             m_interRegionTeleportAttempts.Value++;
 
             m_log.DebugFormat(
-                "[ENTITY TRANSFER MODULE]: {0} transfer version is {1}/{2}, {3} version is {4}", 
-                sp.Scene.Name, OutgoingTransferVersionName, OutgoingTransferVersion, finalDestination.RegionName, version);
+                "[ENTITY TRANSFER MODULE]: {0} transfer version is SIMULATION/{2}, {3} version is {4}", 
+                sp.Scene.Name, version, finalDestination.RegionName, version);
 
             // Fixing a bug where teleporting while sitting results in the avatar ending up removed from
             // both regions
@@ -795,21 +787,15 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
                 agentCircuit.CapsPath = CapsUtil.GetRandomCapsObjectPath();
             }
 
-            // We're going to fallback to V1 if the destination gives us anything smaller than 0.2 or we're forcing
-            // use of the earlier protocol
-            float versionNumber = 0.1f;
-            string[] versionComponents = version.Split(new char[] { '/' });
-            if (versionComponents.Length >= 2)
-                float.TryParse(versionComponents[1], out versionNumber);
-
-            if (versionNumber >= 0.2f)
+            // We're going to fallback to V1 if the destination gives us anything smaller than 0.2
+            if (version >= 0.2f)
                 TransferAgent_V2(sp, agentCircuit, reg, finalDestination, endPoint, teleportFlags, oldRegionX, newRegionX, oldRegionY, newRegionY, version, out reason);
             else
                 TransferAgent_V1(sp, agentCircuit, reg, finalDestination, endPoint, teleportFlags, oldRegionX, newRegionX, oldRegionY, newRegionY, version, out reason);           
         }
 
         private void TransferAgent_V1(ScenePresence sp, AgentCircuitData agentCircuit, GridRegion reg, GridRegion finalDestination,
-            IPEndPoint endPoint, uint teleportFlags, uint oldRegionX, uint newRegionX, uint oldRegionY, uint newRegionY, string version, out string reason)
+            IPEndPoint endPoint, uint teleportFlags, uint oldRegionX, uint newRegionX, uint oldRegionY, uint newRegionY, float version, out string reason)
         {
             ulong destinationHandle = finalDestination.RegionHandle;
             AgentCircuitData currentAgentCircuit = sp.Scene.AuthenticateHandler.GetAgentCircuitData(sp.ControllingClient.CircuitCode);
@@ -1023,7 +1009,7 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
             m_entityTransferStateMachine.UpdateInTransit(sp.UUID, AgentTransferState.CleaningUp);
 
             // For backwards compatibility
-            if (version == "Unknown" || version == string.Empty)
+            if (version == 0f)
             {
                 // CrossAttachmentsIntoNewRegion is a synchronous call. We shouldn't need to wait after it
                 m_log.DebugFormat("[ENTITY TRANSFER MODULE]: Old simulator, sending attachments one by one...");
@@ -1064,7 +1050,7 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
         }
 
         private void TransferAgent_V2(ScenePresence sp, AgentCircuitData agentCircuit, GridRegion reg, GridRegion finalDestination,
-            IPEndPoint endPoint, uint teleportFlags, uint oldRegionX, uint newRegionX, uint oldRegionY, uint newRegionY, string version, out string reason)
+            IPEndPoint endPoint, uint teleportFlags, uint oldRegionX, uint newRegionX, uint oldRegionY, uint newRegionY, float version, out string reason)
         {
             ulong destinationHandle = finalDestination.RegionHandle;
             AgentCircuitData currentAgentCircuit = sp.Scene.AuthenticateHandler.GetAgentCircuitData(sp.ControllingClient.CircuitCode);
@@ -1444,9 +1430,9 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
         //    point is actually in.
         // Returns the coordinates and information of the new region or 'null' of it doesn't exist.
         public GridRegion GetDestination(Scene scene, UUID agentID, Vector3 pos,
-                                            out string version, out Vector3 newpos, out string failureReason)
+                                            out float version, out Vector3 newpos, out string failureReason)
         {
-            version = String.Empty;
+            version = 0f;
             newpos = pos;
             failureReason = string.Empty;
             string homeURI = scene.GetAgentHomeURI(agentID);
@@ -1482,9 +1468,8 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
                 }
 
                 // Check to see if we have access to the target region.
-                string myversion = string.Format("{0}/{1}", OutgoingTransferVersionName, OutgoingTransferVersion);
                 if (neighbourRegion != null
-                    && !scene.SimulationService.QueryAccess(neighbourRegion, agentID, homeURI, false, newpos, myversion, scene.GetFormatsOffered(), out version, out failureReason))
+                    && !scene.SimulationService.QueryAccess(neighbourRegion, agentID, homeURI, false, newpos, scene.GetFormatsOffered(), out version, out failureReason))
                 {
                     // remember banned
                     m_bannedRegionCache.Add(neighbourRegion.RegionHandle, agentID);
@@ -1515,7 +1500,7 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
         public bool Cross(ScenePresence agent, bool isFlying)
         {
             Vector3 newpos;
-            string version;
+            float version;
             string failureReason;
 
             GridRegion neighbourRegion = GetDestination(agent.Scene, agent.UUID, agent.AbsolutePosition,
@@ -1627,7 +1612,7 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
         /// </summary>
         public ScenePresence CrossAgentToNewRegionAsync(
                                 ScenePresence agent, Vector3 pos, GridRegion neighbourRegion,
-                                bool isFlying, string version)
+                                bool isFlying, float version)
         {
             try
             {
@@ -1703,7 +1688,7 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
         }
 
         public void CrossAgentToNewRegionPost(ScenePresence agent, Vector3 pos, GridRegion neighbourRegion,
-            bool isFlying, string version)
+            bool isFlying, float version)
         {
             agent.ControllingClient.RequestClientInfo();
 
@@ -1756,7 +1741,7 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
             agent.SendOtherAgentsAppearanceToClient();
 
             // Backwards compatibility. Best effort
-            if (version == "Unknown" || version == string.Empty)
+            if (version == 0f)
             {
                 m_log.DebugFormat("[ENTITY TRANSFER MODULE]: neighbor with old version, passing attachments one by one...");
                 Thread.Sleep(3000); // wait a little now that we're not waiting for the callback
diff --git a/OpenSim/Region/CoreModules/ServiceConnectorsOut/Simulation/LocalSimulationConnector.cs b/OpenSim/Region/CoreModules/ServiceConnectorsOut/Simulation/LocalSimulationConnector.cs
index 3800b3f..32ac992 100644
--- a/OpenSim/Region/CoreModules/ServiceConnectorsOut/Simulation/LocalSimulationConnector.cs
+++ b/OpenSim/Region/CoreModules/ServiceConnectorsOut/Simulation/LocalSimulationConnector.cs
@@ -81,8 +81,6 @@ namespace OpenSim.Region.CoreModules.ServiceConnectorsOut.Simulation
 
         public void InitialiseService(IConfigSource configSource)
         {
-            ServiceVersion = String.Format("SIMULATION/{0}", VersionInfo.SimulationServiceVersion);
-            m_log.InfoFormat("[LOCAL SIMULATION CONNECTOR]: Initialized with connector protocol version {0}", ServiceVersion);
         }
 
         public void PostInitialise()
@@ -251,10 +249,10 @@ namespace OpenSim.Region.CoreModules.ServiceConnectorsOut.Simulation
             return true;
         }
 
-        public bool QueryAccess(GridRegion destination, UUID agentID, string agentHomeURI, bool viaTeleport, Vector3 position, string theirversion, List<UUID> features, out string version, out string reason)
+        public bool QueryAccess(GridRegion destination, UUID agentID, string agentHomeURI, bool viaTeleport, Vector3 position, List<UUID> features, out float version, out string reason)
         {
             reason = "Communications failure";
-            version = ServiceVersion;
+            version = VersionInfo.SimulationServiceVersionAcceptedMax; // If it's within the process, use max. If it's not, the connector will overwrite this
             if (destination == null)
                 return false;
 
@@ -265,17 +263,12 @@ namespace OpenSim.Region.CoreModules.ServiceConnectorsOut.Simulation
 //                        s.RegionInfo.RegionName, destination.RegionHandle);
                 uint size = m_scenes[destination.RegionID].RegionInfo.RegionSizeX;
 
-                float theirVersionNumber = 0f;
-                string[] versionComponents = theirversion.Split(new char[] { '/' });
-                if (versionComponents.Length >= 2)
-                    float.TryParse(versionComponents[1], out theirVersionNumber);
-
                 // Var regions here, and the requesting simulator is in an older version.
                 // We will forbide this, because it crashes the viewers
-                if (theirVersionNumber < 0.3f && size > 256)
+                if (version < 0.3f && size != 256)
                 {
                     reason = "Destination is a variable-sized region, and source is an old simulator. Consider upgrading.";
-                    m_log.DebugFormat("[LOCAL SIMULATION CONNECTOR]: Request to access this variable-sized region from {0} simulator was denied", theirVersionNumber);
+                    m_log.DebugFormat("[LOCAL SIMULATION CONNECTOR]: Request to access this variable-sized region from older simulator was denied");
                     return false;
                 
                 }
diff --git a/OpenSim/Region/CoreModules/ServiceConnectorsOut/Simulation/RemoteSimulationConnector.cs b/OpenSim/Region/CoreModules/ServiceConnectorsOut/Simulation/RemoteSimulationConnector.cs
index f963242..e2f52c4 100644
--- a/OpenSim/Region/CoreModules/ServiceConnectorsOut/Simulation/RemoteSimulationConnector.cs
+++ b/OpenSim/Region/CoreModules/ServiceConnectorsOut/Simulation/RemoteSimulationConnector.cs
@@ -205,21 +205,21 @@ namespace OpenSim.Region.CoreModules.ServiceConnectorsOut.Simulation
             return m_remoteConnector.UpdateAgent(destination, cAgentData);
         }
 
-        public bool QueryAccess(GridRegion destination, UUID agentID, string agentHomeURI, bool viaTeleport, Vector3 position, string sversion, List<UUID> features, out string version, out string reason)
+        public bool QueryAccess(GridRegion destination, UUID agentID, string agentHomeURI, bool viaTeleport, Vector3 position, List<UUID> features, out float version, out string reason)
         {
             reason = "Communications failure";
-            version = "Unknown";
+            version = 0f;
 
             if (destination == null)
                 return false;
 
             // Try local first
-            if (m_localBackend.QueryAccess(destination, agentID, agentHomeURI, viaTeleport, position, sversion, features, out version, out reason))
+            if (m_localBackend.QueryAccess(destination, agentID, agentHomeURI, viaTeleport, position, features, out version, out reason))
                 return true;
 
             // else do the remote thing
             if (!m_localBackend.IsLocalRegion(destination.RegionID))
-                return m_remoteConnector.QueryAccess(destination, agentID, agentHomeURI, viaTeleport, position, sversion, features, out version, out reason);
+                return m_remoteConnector.QueryAccess(destination, agentID, agentHomeURI, viaTeleport, position, features, out version, out reason);
 
             return false;
         }
diff --git a/OpenSim/Region/Framework/Interfaces/IEntityTransferModule.cs b/OpenSim/Region/Framework/Interfaces/IEntityTransferModule.cs
index 1ebef90..9e91d7d 100644
--- a/OpenSim/Region/Framework/Interfaces/IEntityTransferModule.cs
+++ b/OpenSim/Region/Framework/Interfaces/IEntityTransferModule.cs
@@ -35,7 +35,7 @@ using OpenSim.Region.Framework.Scenes;
 
 namespace OpenSim.Region.Framework.Interfaces
 {
-    public delegate ScenePresence CrossAgentToNewRegionDelegate(ScenePresence agent, Vector3 pos, GridRegion neighbourRegion, bool isFlying, string version);
+    public delegate ScenePresence CrossAgentToNewRegionDelegate(ScenePresence agent, Vector3 pos, GridRegion neighbourRegion, bool isFlying, float version);
 
     public interface IEntityTransferModule
     {
@@ -92,12 +92,12 @@ namespace OpenSim.Region.Framework.Interfaces
 
         void EnableChildAgent(ScenePresence agent, GridRegion region);
 
-        GridRegion GetDestination(Scene scene, UUID agentID, Vector3 pos, out string version,
+        GridRegion GetDestination(Scene scene, UUID agentID, Vector3 pos, out float version,
                                         out Vector3 newpos, out string reason);
 
         void Cross(SceneObjectGroup sog, Vector3 position, bool silent);
 
-        ScenePresence CrossAgentToNewRegionAsync(ScenePresence agent, Vector3 pos, GridRegion neighbourRegion, bool isFlying, string version);
+        ScenePresence CrossAgentToNewRegionAsync(ScenePresence agent, Vector3 pos, GridRegion neighbourRegion, bool isFlying, float version);
 
         bool HandleIncomingSceneObject(SceneObjectGroup so, Vector3 newPosition);
     }
diff --git a/OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs b/OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs
index f3b3a9c..3b13e64 100644
--- a/OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs
+++ b/OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs
@@ -476,7 +476,7 @@ namespace OpenSim.Region.Framework.Scenes
                         )
                     {
                         IEntityTransferModule entityTransfer = m_scene.RequestModuleInterface<IEntityTransferModule>();
-                        string version = String.Empty;
+                        float version = 0f;
                         Vector3 newpos = Vector3.Zero;
                         string failureReason = String.Empty;
                         OpenSim.Services.Interfaces.GridRegion destination = null;
diff --git a/OpenSim/Server/Handlers/Simulation/AgentHandlers.cs b/OpenSim/Server/Handlers/Simulation/AgentHandlers.cs
index 8b4518c..e0fa799 100644
--- a/OpenSim/Server/Handlers/Simulation/AgentHandlers.cs
+++ b/OpenSim/Server/Handlers/Simulation/AgentHandlers.cs
@@ -145,9 +145,96 @@ namespace OpenSim.Server.Handlers.Simulation
             if (args.ContainsKey("agent_home_uri"))
                 agentHomeURI = args["agent_home_uri"].AsString();
 
-            string theirVersion = string.Empty;
+            // Decode the legacy (string) version and extract the number
+            float theirVersion = 0f;
             if (args.ContainsKey("my_version"))
-                theirVersion = args["my_version"].AsString();
+            {
+                string theirVersionStr = args["my_version"].AsString();
+                string[] parts = theirVersionStr.Split(new char[] {'/'});
+                if (parts.Length > 1)
+                    theirVersion = float.Parse(parts[1]);
+            }
+
+            // Decode the new versioning data
+            float minVersionRequired = 0f;
+            float maxVersionRequired = 0f;
+            float minVersionProvided = 0f;
+            float maxVersionProvided = 0f;
+
+            if (args.ContainsKey("simulation_service_supported_min"))
+                minVersionProvided = (float)args["simulation_service_supported_min"].AsReal();
+            if (args.ContainsKey("simulation_service_supported_max"))
+                maxVersionProvided = (float)args["simulation_service_supported_max"].AsReal();
+
+            if (args.ContainsKey("simulation_service_accepted_min"))
+                minVersionRequired = (float)args["simulation_service_accepted_min"].AsReal();
+            if (args.ContainsKey("simulation_service_accepted_max"))
+                maxVersionRequired = (float)args["simulation_service_accepted_max"].AsReal();
+
+            responsedata["int_response_code"] = HttpStatusCode.OK;
+            OSDMap resp = new OSDMap(3);
+
+
+            // If there is no version in the packet at all we're looking at 0.6 or
+            // even more ancient. Refuse it.
+            if (minVersionProvided == 0f && theirVersion == 0f) // 0.6 or earlier
+            {
+                resp["success"] = OSD.FromBoolean(false);
+                resp["reason"] = OSD.FromString("Version not supported");
+                responsedata["str_response_string"] = OSDParser.SerializeJsonString(resp, true);
+                return;
+            }
+
+            float version;
+
+            if (minVersionProvided == 0f) // Legacy version
+            {
+                if (theirVersion >= VersionInfo.SimulationServiceVersionAcceptedMin &&
+                    theirVersion <= VersionInfo.SimulationServiceVersionAcceptedMax)
+                {
+                    version = Math.Max(theirVersion, VersionInfo.SimulationServiceVersionAcceptedMax);
+                }
+                else
+                {
+                    resp["success"] = OSD.FromBoolean(false);
+                    resp["reason"] = OSD.FromString(String.Format("Your version is {0} and we accept only {1} - {2}", theirVersion, VersionInfo.SimulationServiceVersionAcceptedMin, VersionInfo.SimulationServiceVersionAcceptedMax));
+                    responsedata["str_response_string"] = OSDParser.SerializeJsonString(resp, true);
+                    return;
+                }
+            }
+            else
+            {
+                // Test for no overlap
+                if (minVersionProvided > VersionInfo.SimulationServiceVersionAcceptedMax ||
+                    maxVersionProvided < VersionInfo.SimulationServiceVersionAcceptedMin)
+                {
+                    resp["success"] = OSD.FromBoolean(false);
+                    resp["reason"] = OSD.FromString(String.Format("You provide versions {0} - {1} and we accept only {2} - {3}. No version overlap.", minVersionProvided, maxVersionProvided, VersionInfo.SimulationServiceVersionAcceptedMin, VersionInfo.SimulationServiceVersionAcceptedMax));
+                    responsedata["str_response_string"] = OSDParser.SerializeJsonString(resp, true);
+                    return;
+                }
+                if (minVersionRequired > VersionInfo.SimulationServiceVersionSupportedMax ||
+                    maxVersionRequired < VersionInfo.SimulationServiceVersionSupportedMin)
+                {
+                    resp["success"] = OSD.FromBoolean(false);
+                    resp["reason"] = OSD.FromString(String.Format("You require versions {0} - {1} and we provide only {2} - {3}. No version overlap.", minVersionRequired, maxVersionRequired, VersionInfo.SimulationServiceVersionSupportedMin, VersionInfo.SimulationServiceVersionSupportedMax));
+                    responsedata["str_response_string"] = OSDParser.SerializeJsonString(resp, true);
+                    return;
+                }
+
+                // Determine version to use
+                version = Math.Max(Math.Max(maxVersionProvided, VersionInfo.SimulationServiceVersionAcceptedMax), Math.Max(maxVersionRequired, VersionInfo.SimulationServiceVersionSupportedMax));
+                if (version < VersionInfo.SimulationServiceVersionAcceptedMin ||
+                    version > VersionInfo.SimulationServiceVersionAcceptedMax ||
+                    version < VersionInfo.SimulationServiceVersionSupportedMin ||
+                    version > VersionInfo.SimulationServiceVersionSupportedMax)
+                {
+                    resp["success"] = OSD.FromBoolean(false);
+                    resp["reason"] = OSD.FromString(String.Format("The protocol version we determined, {0}, is incompatible with the version windows, {1} - {2} and {3} - {4}. No version overlap.", version, VersionInfo.SimulationServiceVersionAcceptedMin, VersionInfo.SimulationServiceVersionAcceptedMax, VersionInfo.SimulationServiceVersionSupportedMin, VersionInfo.SimulationServiceVersionSupportedMax));
+                    responsedata["str_response_string"] = OSDParser.SerializeJsonString(resp, true);
+                    return;
+                }
+            }
 
             List<UUID> features = new List<UUID>();
 
@@ -163,16 +250,14 @@ namespace OpenSim.Server.Handlers.Simulation
             destination.RegionID = regionID;
 
             string reason;
-            string version;
-            bool result = m_SimulationService.QueryAccess(destination, agentID, agentHomeURI, viaTeleport, position, theirVersion, features, out version, out reason);
-
-            responsedata["int_response_code"] = HttpStatusCode.OK;
-
-            OSDMap resp = new OSDMap(3);
+            float dummyVersion;
+            bool result = m_SimulationService.QueryAccess(destination, agentID, agentHomeURI, viaTeleport, position, features, out dummyVersion, out reason);
 
             resp["success"] = OSD.FromBoolean(result);
             resp["reason"] = OSD.FromString(reason);
-            resp["version"] = OSD.FromString(version);
+            string legacyVersion = String.Format("SIMULATION/{0}", version);
+            resp["version"] = OSD.FromString(legacyVersion);
+            resp["negotiated_version"] = OSD.FromReal(version);
             resp["variable_wearables_count_supported"] = OSD.FromBoolean(true);
 
             OSDArray featuresWanted = new OSDArray();
diff --git a/OpenSim/Services/Connectors/Simulation/SimulationServiceConnector.cs b/OpenSim/Services/Connectors/Simulation/SimulationServiceConnector.cs
index 1eedbef..5ee2c9c 100644
--- a/OpenSim/Services/Connectors/Simulation/SimulationServiceConnector.cs
+++ b/OpenSim/Services/Connectors/Simulation/SimulationServiceConnector.cs
@@ -282,10 +282,10 @@ namespace OpenSim.Services.Connectors.Simulation
         }
 
 
-        public bool QueryAccess(GridRegion destination, UUID agentID, string agentHomeURI, bool viaTeleport, Vector3 position, string myversion, List<UUID> featuresAvailable, out string version, out string reason)
+        public bool QueryAccess(GridRegion destination, UUID agentID, string agentHomeURI, bool viaTeleport, Vector3 position, List<UUID> featuresAvailable, out float version, out string reason)
         {
             reason = "Failed to contact destination";
-            version = "Unknown";
+            version = 0f;
 
             // m_log.DebugFormat("[REMOTE SIMULATION CONNECTOR]: QueryAccess start, position={0}", position);
 
@@ -298,7 +298,14 @@ namespace OpenSim.Services.Connectors.Simulation
             OSDMap request = new OSDMap();
             request.Add("viaTeleport", OSD.FromBoolean(viaTeleport));
             request.Add("position", OSD.FromString(position.ToString()));
-            request.Add("my_version", OSD.FromString(myversion));
+            // To those who still understad this field, we're telling them 
+            // the lowest version just to be safe
+            request.Add("my_version", OSD.FromString(String.Format("SIMULATION/{0}", VersionInfo.SimulationServiceVersionSupportedMin)));
+            // New simulation service negotiation
+            request.Add("simulation_service_supported_min", OSD.FromReal(VersionInfo.SimulationServiceVersionSupportedMin));
+            request.Add("simulation_service_supported_max", OSD.FromReal(VersionInfo.SimulationServiceVersionSupportedMax));
+            request.Add("simulation_service_accepted_min", OSD.FromReal(VersionInfo.SimulationServiceVersionAcceptedMin));
+            request.Add("simulation_service_accepted_max", OSD.FromReal(VersionInfo.SimulationServiceVersionAcceptedMax));
 
             OSDArray features = new OSDArray();
             foreach (UUID feature in featuresAvailable)
@@ -322,15 +329,24 @@ namespace OpenSim.Services.Connectors.Simulation
                     success = data["success"];
 
                     reason = data["reason"].AsString();
-                    if (data["version"] != null && data["version"].AsString() != string.Empty)
-                        version = data["version"].AsString();
+                    if (data["negotiated_version"] != null)
+                    {
+                        version = (float)data["negotiated_version"].AsReal();
+                    }
+                    else if (data["version"] != null && data["version"].AsString() != string.Empty)
+                    {
+                        string versionString = data["version"].AsString();
+                        String[] parts = versionString.Split(new char[] {'/'});
+                        if (parts.Length > 1)
+                            version = float.Parse(parts[1]);
+                    }
 
                     m_log.DebugFormat(
-                        "[REMOTE SIMULATION CONNECTOR]: QueryAccess to {0} returned {1}, reason {2}, version {3} ({4})",
-                        uri, success, reason, version, data["version"].AsString());
+                        "[REMOTE SIMULATION CONNECTOR]: QueryAccess to {0} returned {1}, reason {2}, version SIMULATION/{3}",
+                        uri, success, reason, version);
                 }
 
-                if (!success)
+                if (!success || version == 0f)
                 {
                     // If we don't check this then OpenSimulator 0.7.3.1 and some period before will never see the
                     // actual failure message
diff --git a/OpenSim/Services/HypergridService/GatekeeperService.cs b/OpenSim/Services/HypergridService/GatekeeperService.cs
index bee3db3..a2c5327 100644
--- a/OpenSim/Services/HypergridService/GatekeeperService.cs
+++ b/OpenSim/Services/HypergridService/GatekeeperService.cs
@@ -452,12 +452,11 @@ namespace OpenSim.Services.HypergridService
 
             m_log.DebugFormat("[GATEKEEPER SERVICE]: Launching {0}, Teleport Flags: {1}", aCircuit.Name, loginFlag);
 
-            string version;
+            float version;
 
-            string myversion = String.Format("SIMULATION/{0}", VersionInfo.SimulationServiceVersion);
             if (!m_SimulationService.QueryAccess(
                 destination, aCircuit.AgentID, aCircuit.ServiceURLs["HomeURI"].ToString(), 
-                true, aCircuit.startpos, myversion, new List<UUID>(), out version, out reason))
+                true, aCircuit.startpos, new List<UUID>(), out version, out reason))
                 return false;
 
             return m_SimulationService.CreateAgent(source, destination, aCircuit, (uint)loginFlag, out reason);
diff --git a/OpenSim/Services/Interfaces/ISimulationService.cs b/OpenSim/Services/Interfaces/ISimulationService.cs
index 42c414d..6f205ad 100644
--- a/OpenSim/Services/Interfaces/ISimulationService.cs
+++ b/OpenSim/Services/Interfaces/ISimulationService.cs
@@ -92,7 +92,7 @@ namespace OpenSim.Services.Interfaces
         /// <param name="version">Version that the target simulator is running</param>
         /// <param name="reason">[out] Optional error message</param>
         /// <returns>True: ok; False: not allowed</returns>
-        bool QueryAccess(GridRegion destination, UUID agentID, string agentHomeURI, bool viaTeleport, Vector3 position, string sversion, List<UUID> features, out string version, out string reason);
+        bool QueryAccess(GridRegion destination, UUID agentID, string agentHomeURI, bool viaTeleport, Vector3 position, List<UUID> features, out float version, out string reason);
 
         /// <summary>
         /// Message from receiving region to departing region, telling it got contacted by the client.
diff --git a/OpenSim/Services/LLLoginService/LLLoginService.cs b/OpenSim/Services/LLLoginService/LLLoginService.cs
index 9e12f9d..4f8f459 100644
--- a/OpenSim/Services/LLLoginService/LLLoginService.cs
+++ b/OpenSim/Services/LLLoginService/LLLoginService.cs
@@ -983,11 +983,10 @@ namespace OpenSim.Services.LLLoginService
 
         private bool LaunchAgentDirectly(ISimulationService simConnector, GridRegion region, AgentCircuitData aCircuit, TeleportFlags flags, out string reason)
         {
-            string myversion = String.Format("SIMULATION/{0}", VersionInfo.SimulationServiceVersion);
-            string version;
+            float version;
 
             if (!simConnector.QueryAccess(
-                    region, aCircuit.AgentID, null, true, aCircuit.startpos, myversion, new List<UUID>(), out version, out reason))
+                    region, aCircuit.AgentID, null, true, aCircuit.startpos, new List<UUID>(), out version, out reason))
                 return false;
 
             return simConnector.CreateAgent(null, region, aCircuit, (uint)flags, out reason);