diff --git a/web/gui/src/main/webapp/index2.html b/web/gui/src/main/webapp/index2.html
index 6168271..9688522 100644
--- a/web/gui/src/main/webapp/index2.html
+++ b/web/gui/src/main/webapp/index2.html
@@ -90,6 +90,7 @@
     <script src="sampleAlt2.js"></script>
     <script src="sampleRadio.js"></script>
     <script src="sampleKeys.js"></script>
+    <script src="sampleHash.js"></script>
 
     <!-- Contributed (application) views injected here -->
     <!-- TODO: replace with template marker and inject refs server-side -->
diff --git a/web/gui/src/main/webapp/json/intent/ev_1_ui.json b/web/gui/src/main/webapp/json/ev/intent/ev_1_ui.json
similarity index 100%
rename from web/gui/src/main/webapp/json/intent/ev_1_ui.json
rename to web/gui/src/main/webapp/json/ev/intent/ev_1_ui.json
diff --git a/web/gui/src/main/webapp/json/intent/ev_2_onos.json b/web/gui/src/main/webapp/json/ev/intent/ev_2_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/intent/ev_2_onos.json
rename to web/gui/src/main/webapp/json/ev/intent/ev_2_onos.json
diff --git a/web/gui/src/main/webapp/json/intent/ev_3_ui.json b/web/gui/src/main/webapp/json/ev/intent/ev_3_ui.json
similarity index 100%
rename from web/gui/src/main/webapp/json/intent/ev_3_ui.json
rename to web/gui/src/main/webapp/json/ev/intent/ev_3_ui.json
diff --git a/web/gui/src/main/webapp/json/intent/ev_4_onos.json b/web/gui/src/main/webapp/json/ev/intent/ev_4_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/intent/ev_4_onos.json
rename to web/gui/src/main/webapp/json/ev/intent/ev_4_onos.json
diff --git a/web/gui/src/main/webapp/json/intent/ev_5_onos.json b/web/gui/src/main/webapp/json/ev/intent/ev_5_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/intent/ev_5_onos.json
rename to web/gui/src/main/webapp/json/ev/intent/ev_5_onos.json
diff --git a/web/gui/src/main/webapp/json/intent/ev_6_onos.json b/web/gui/src/main/webapp/json/ev/intent/ev_6_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/intent/ev_6_onos.json
rename to web/gui/src/main/webapp/json/ev/intent/ev_6_onos.json
diff --git a/web/gui/src/main/webapp/json/intent/ev_7_ui.json b/web/gui/src/main/webapp/json/ev/intent/ev_7_ui.json
similarity index 100%
rename from web/gui/src/main/webapp/json/intent/ev_7_ui.json
rename to web/gui/src/main/webapp/json/ev/intent/ev_7_ui.json
diff --git a/web/gui/src/main/webapp/json/ev/intent/scenario.json b/web/gui/src/main/webapp/json/ev/intent/scenario.json
new file mode 100644
index 0000000..136d027
--- /dev/null
+++ b/web/gui/src/main/webapp/json/ev/intent/scenario.json
@@ -0,0 +1,9 @@
+{
+  "comments": [
+    "This scenario steps through adding a host intent."
+  ],
+  "title": "Host Intent Scenario",
+  "params": {
+    "lastAuto": 0
+  }
+}
\ No newline at end of file
diff --git a/web/gui/src/main/webapp/json/ev/simple/ev_1_onos.json b/web/gui/src/main/webapp/json/ev/simple/ev_1_onos.json
new file mode 100644
index 0000000..1776f94
--- /dev/null
+++ b/web/gui/src/main/webapp/json/ev/simple/ev_1_onos.json
@@ -0,0 +1,17 @@
+{
+  "event": "addDevice",
+  "payload": {
+    "id": "of:0000ffffffff0008",
+    "type": "switch",
+    "online": false,
+    "labels": [
+      "0000ffffffff0008",
+      "FF:FF:FF:FF:00:08",
+      "sw-8"
+    ],
+    "metaUi": {
+      "x": 400,
+      "y": 280
+    }
+  }
+}
diff --git a/web/gui/src/main/webapp/json/ev/simple/ev_2_onos.json b/web/gui/src/main/webapp/json/ev/simple/ev_2_onos.json
new file mode 100644
index 0000000..4f9b32a
--- /dev/null
+++ b/web/gui/src/main/webapp/json/ev/simple/ev_2_onos.json
@@ -0,0 +1,17 @@
+{
+  "event": "addDevice",
+  "payload": {
+    "id": "of:0000ffffffff0003",
+    "type": "switch",
+    "online": false,
+    "labels": [
+      "0000ffffffff0003",
+      "FF:FF:FF:FF:00:03",
+      "sw-3"
+    ],
+    "metaUi": {
+      "x": 800,
+      "y": 280
+    }
+  }
+}
diff --git a/web/gui/src/main/webapp/json/ev/simple/ev_3_onos.json b/web/gui/src/main/webapp/json/ev/simple/ev_3_onos.json
new file mode 100644
index 0000000..3312682
--- /dev/null
+++ b/web/gui/src/main/webapp/json/ev/simple/ev_3_onos.json
@@ -0,0 +1,14 @@
+{
+  "event": "addLink",
+  "payload": {
+    "src": "of:0000ffffffff0003",
+    "srcPort": "21",
+    "dst": "of:0000ffffffff0008",
+    "dstPort": "20",
+    "type": "infra",
+    "linkWidth": 2,
+    "props" : {
+      "BW": "70 G"
+    }
+  }
+}
diff --git a/web/gui/src/main/webapp/json/ev/simple/ev_4_onos.json b/web/gui/src/main/webapp/json/ev/simple/ev_4_onos.json
new file mode 100644
index 0000000..51fdb8c
--- /dev/null
+++ b/web/gui/src/main/webapp/json/ev/simple/ev_4_onos.json
@@ -0,0 +1,16 @@
+{
+  "event": "addHost",
+  "payload": {
+    "id": "00:00:00:00:00:03/-1",
+    "cp": {
+      "device": "of:0000ffffffff0003",
+      "port": 1
+    },
+    "labels": [
+      "10.0.0.3",
+      "00:00:00:00:00:03"
+    ],
+    "metaUi": {
+    }
+  }
+}
diff --git a/web/gui/src/main/webapp/json/ev/simple/ev_5_onos.json b/web/gui/src/main/webapp/json/ev/simple/ev_5_onos.json
new file mode 100644
index 0000000..a6489b2
--- /dev/null
+++ b/web/gui/src/main/webapp/json/ev/simple/ev_5_onos.json
@@ -0,0 +1,16 @@
+{
+  "event": "addHost",
+  "payload": {
+    "id": "00:00:00:00:00:08/-1",
+    "cp": {
+      "device": "of:0000ffffffff0008",
+      "port": 1
+    },
+    "labels": [
+      "10.0.0.8",
+      "00:00:00:00:00:08"
+    ],
+    "metaUi": {
+    }
+  }
+}
diff --git a/web/gui/src/main/webapp/json/ev/simple/scenario.json b/web/gui/src/main/webapp/json/ev/simple/scenario.json
new file mode 100644
index 0000000..d24626f
--- /dev/null
+++ b/web/gui/src/main/webapp/json/ev/simple/scenario.json
@@ -0,0 +1,9 @@
+{
+  "comments": [
+    "Add two devices and one link (auto), and two hosts."
+  ],
+  "title": "Simple Startup Scenario",
+  "params": {
+    "lastAuto": 0
+  }
+}
\ No newline at end of file
diff --git a/web/gui/src/main/webapp/json/eventTest_10.json b/web/gui/src/main/webapp/json/ev/startup/ev_10_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_10.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_10_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_11.json b/web/gui/src/main/webapp/json/ev/startup/ev_11_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_11.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_11_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_12.json b/web/gui/src/main/webapp/json/ev/startup/ev_12_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_12.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_12_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_13.json b/web/gui/src/main/webapp/json/ev/startup/ev_13_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_13.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_13_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_14.json b/web/gui/src/main/webapp/json/ev/startup/ev_14_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_14.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_14_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_15.json b/web/gui/src/main/webapp/json/ev/startup/ev_15_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_15.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_15_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_16.json b/web/gui/src/main/webapp/json/ev/startup/ev_16_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_16.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_16_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_17.json b/web/gui/src/main/webapp/json/ev/startup/ev_17_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_17.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_17_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_18.json b/web/gui/src/main/webapp/json/ev/startup/ev_18_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_18.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_18_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_19.json b/web/gui/src/main/webapp/json/ev/startup/ev_19_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_19.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_19_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_1.json b/web/gui/src/main/webapp/json/ev/startup/ev_1_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_1.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_1_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_20.json b/web/gui/src/main/webapp/json/ev/startup/ev_20_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_20.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_20_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_21.json b/web/gui/src/main/webapp/json/ev/startup/ev_21_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_21.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_21_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_22.json b/web/gui/src/main/webapp/json/ev/startup/ev_22_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_22.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_22_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_23.json b/web/gui/src/main/webapp/json/ev/startup/ev_23_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_23.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_23_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_24.json b/web/gui/src/main/webapp/json/ev/startup/ev_24_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_24.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_24_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_25.json b/web/gui/src/main/webapp/json/ev/startup/ev_25_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_25.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_25_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_26.json b/web/gui/src/main/webapp/json/ev/startup/ev_26_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_26.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_26_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_27.json b/web/gui/src/main/webapp/json/ev/startup/ev_27_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_27.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_27_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_28.json b/web/gui/src/main/webapp/json/ev/startup/ev_28_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_28.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_28_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_29.json b/web/gui/src/main/webapp/json/ev/startup/ev_29_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_29.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_29_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_2.json b/web/gui/src/main/webapp/json/ev/startup/ev_2_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_2.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_2_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_30.json b/web/gui/src/main/webapp/json/ev/startup/ev_30_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_30.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_30_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_31.json b/web/gui/src/main/webapp/json/ev/startup/ev_31_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_31.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_31_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_32.json b/web/gui/src/main/webapp/json/ev/startup/ev_32_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_32.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_32_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_33.json b/web/gui/src/main/webapp/json/ev/startup/ev_33_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_33.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_33_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_34.json b/web/gui/src/main/webapp/json/ev/startup/ev_34_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_34.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_34_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_35.json b/web/gui/src/main/webapp/json/ev/startup/ev_35_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_35.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_35_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_3.json b/web/gui/src/main/webapp/json/ev/startup/ev_3_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_3.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_3_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_4.json b/web/gui/src/main/webapp/json/ev/startup/ev_4_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_4.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_4_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_5.json b/web/gui/src/main/webapp/json/ev/startup/ev_5_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_5.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_5_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_6.json b/web/gui/src/main/webapp/json/ev/startup/ev_6_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_6.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_6_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_7.json b/web/gui/src/main/webapp/json/ev/startup/ev_7_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_7.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_7_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_8.json b/web/gui/src/main/webapp/json/ev/startup/ev_8_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_8.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_8_onos.json
diff --git a/web/gui/src/main/webapp/json/eventTest_9.json b/web/gui/src/main/webapp/json/ev/startup/ev_9_onos.json
similarity index 100%
rename from web/gui/src/main/webapp/json/eventTest_9.json
rename to web/gui/src/main/webapp/json/ev/startup/ev_9_onos.json
diff --git a/web/gui/src/main/webapp/json/ev/startup/scenario.json b/web/gui/src/main/webapp/json/ev/startup/scenario.json
new file mode 100644
index 0000000..37939ca0
--- /dev/null
+++ b/web/gui/src/main/webapp/json/ev/startup/scenario.json
@@ -0,0 +1,10 @@
+{
+  "comments": [
+    "This scenario steps through adding devices and links.",
+    "(Typical 'start-ip' of the view.)"
+  ],
+  "title": "Startup Scenario",
+  "params": {
+    "lastAuto": 32
+  }
+}
\ No newline at end of file
diff --git a/web/gui/src/main/webapp/onos2.js b/web/gui/src/main/webapp/onos2.js
index 4aeb23e..a0276df 100644
--- a/web/gui/src/main/webapp/onos2.js
+++ b/web/gui/src/main/webapp/onos2.js
@@ -52,6 +52,7 @@
             current = {
                 view: null,
                 ctx: '',
+                flags: {},
                 theme: settings.theme
             },
             built = false,
@@ -110,6 +111,7 @@
         function doError(msg) {
             errorCount++;
             console.error(msg);
+            doAlert(msg);
         }
 
         function trace(msg) {
@@ -140,7 +142,7 @@
 
             t = parseHash(hash);
             if (!t || !t.vid) {
-                doError('Unable to parse target hash: ' + hash);
+                doError('Unable to parse target hash: "' + hash + '"');
             }
 
             view = views[t.vid];
@@ -160,33 +162,72 @@
 
         function parseHash(s) {
             // extract navigation coordinates from the supplied string
-            // "vid,ctx" --> { vid:vid, ctx:ctx }
+            // "vid,ctx?flag1,flag2" --> { vid:vid, ctx:ctx, flags:{...} }
             traceFn('parseHash', s);
 
-            var m = /^[#]{0,1}(\S+),(\S*)$/.exec(s);
+            // look for use of flags, first
+            var vidctx,
+                vid,
+                ctx,
+                flags,
+                flagMap,
+                m;
+
+            // RE that includes flags ('?flag1,flag2')
+            m = /^[#]{0,1}(.+)\?(.+)$/.exec(s);
             if (m) {
-                return { vid: m[1], ctx: m[2] };
+                vidctx = m[1];
+                flags = m[2];
+                flagMap = {};
+            } else {
+                // no flags
+                m = /^[#]{0,1}((.+)(,.+)*)$/.exec(s);
+                if (m) {
+                    vidctx = m[1];
+                } else {
+                    // bad hash
+                    return null;
+                }
             }
 
-            m = /^[#]{0,1}(\S+)$/.exec(s);
-            return m ? { vid: m[1] } : null;
+            vidctx = vidctx.split(',');
+            vid = vidctx[0];
+            ctx = vidctx[1];
+            if (flags) {
+                flags.split(',').forEach(function (f) {
+                    flagMap[f.trim()] = true;
+                });
+            }
+
+            return {
+                vid: vid.trim(),
+                ctx: ctx ? ctx.trim() : '',
+                flags: flagMap
+            };
+
         }
 
-        function makeHash(t, ctx) {
+        function makeHash(t, ctx, flags) {
             traceFn('makeHash');
-            // make a hash string from the given navigation coordinates.
+            // make a hash string from the given navigation coordinates,
+            // and optional flags map.
             // if t is not an object, then it is a vid
             var h = t,
-                c = ctx || '';
+                c = ctx || '',
+                f = $.isPlainObject(flags) ? flags : null;
 
             if ($.isPlainObject(t)) {
                 h = t.vid;
                 c = t.ctx || '';
+                f = t.flags || null;
             }
 
             if (c) {
                 h += ',' + c;
             }
+            if (f) {
+                h += '?' + d3.map(f).keys().join(',');
+            }
             trace('hash = "' + h + '"');
             return h;
         }
@@ -244,6 +285,9 @@
             // set the specified view as current, while invoking the
             // appropriate life-cycle callbacks
 
+            // first, we'll start by closing the alerts pane, if open
+            closeAlerts();
+
             // if there is a current view, and it is not the same as
             // the incoming view, then unload it...
             if (current.view && (current.view.vid !== view.vid)) {
@@ -258,10 +302,11 @@
             // cache new view and context
             current.view = view;
             current.ctx = t.ctx || '';
+            current.flags = t.flags || {};
 
             // preload is called only once, after the view is in the DOM
             if (!view.preloaded) {
-                view.preload(current.ctx);
+                view.preload(current.ctx, current.flags);
                 view.preloaded = true;
             }
 
@@ -269,7 +314,7 @@
             view.reset();
 
             // load the view
-            view.load(current.ctx);
+            view.load(current.ctx, current.flags);
         }
 
         // generate 'unique' id by prefixing view id
@@ -454,7 +499,7 @@
             d3.selectAll('.onosView').call(setViewDimensions);
             // allow current view to react to resize event...
             if (current.view) {
-                current.view.resize(current.ctx);
+                current.view.resize(current.ctx, current.flags);
             }
         }
 
@@ -521,13 +566,13 @@
                 }
             },
 
-            preload: function (ctx) {
+            preload: function (ctx, flags) {
                 var c = ctx || '',
                     fn = isF(this.cb.preload);
                 traceFn('View.preload', this.vid + ', ' + c);
                 if (fn) {
                     trace('PRELOAD cb for ' + this.vid);
-                    fn(this.token(), c);
+                    fn(this.token(), c, flags);
                 }
             },
 
@@ -544,15 +589,14 @@
                 }
             },
 
-            load: function (ctx) {
+            load: function (ctx, flags) {
                 var c = ctx || '',
                     fn = isF(this.cb.load);
                 traceFn('View.load', this.vid + ', ' + c);
                 this.$div.classed('currentView', true);
-                // TODO: add radio button set, if needed
                 if (fn) {
                     trace('LOAD cb for ' + this.vid);
-                    fn(this.token(), c);
+                    fn(this.token(), c, flags);
                 }
             },
 
@@ -560,14 +604,13 @@
                 var fn = isF(this.cb.unload);
                 traceFn('View.unload', this.vid);
                 this.$div.classed('currentView', false);
-                // TODO: remove radio button set, if needed
                 if (fn) {
                     trace('UNLOAD cb for ' + this.vid);
                     fn(this.token());
                 }
             },
 
-            resize: function (ctx) {
+            resize: function (ctx, flags) {
                 var c = ctx || '',
                     fn = isF(this.cb.resize),
                     w = this.width(),
@@ -576,7 +619,7 @@
                         ' [' + w + 'x' + h + ']');
                 if (fn) {
                     trace('RESIZE cb for ' + this.vid);
-                    fn(this.token(), c);
+                    fn(this.token(), c, flags);
                 }
             },
 
diff --git a/web/gui/src/main/webapp/preamble.js b/web/gui/src/main/webapp/preamble.js
index 8ee8e45..b6a8c02 100644
--- a/web/gui/src/main/webapp/preamble.js
+++ b/web/gui/src/main/webapp/preamble.js
@@ -21,12 +21,17 @@
  */
 
 (function () {
+
+    // NOTE: DON'T Want to do this.. we want to be able to
+    //  use the parameter section, for example:
+    //   #viewId,context?flag1,flag2,flag3
+
     // Check if the URL in the address bar contains a parameter section
     // (delineated by '?'). If this is the case, rewrite using '#' instead.
 
-    var m = /([^?]*)\?(.*)/.exec(window.location.href);
-    if (m) {
-        window.location.href = m[1] + '#' + m[2];
-    }
+    //var m = /([^?]*)\?(.*)/.exec(window.location.href);
+    //if (m) {
+    //    window.location.href = m[1] + '#' + m[2];
+    //}
 
 }());
diff --git a/web/gui/src/main/webapp/sampleHash.js b/web/gui/src/main/webapp/sampleHash.js
new file mode 100644
index 0000000..c94ebb8
--- /dev/null
+++ b/web/gui/src/main/webapp/sampleHash.js
@@ -0,0 +1,84 @@
+/*
+ * Copyright 2014 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+ Sample view to illustrate hash formats.
+
+ @author Simon Hunt
+ */
+
+(function (onos) {
+    'use strict';
+
+    var intro = "Try using the following hashes in the address bar:",
+        hashPrefix = '#sampleHash',
+        suffixes = [
+            '',
+            ',one',
+            ',two',
+            ',context,ignored',
+            ',context,ignored?a,b,c',
+            ',two?foo',
+            ',three?foo,bar'
+        ],
+        $d;
+
+    function note(txt) {
+        $d.append('p')
+            .text(txt)
+            .style({
+                'font-size': '10pt',
+                color: 'darkorange',
+                padding: '0 20px',
+                margin: 0
+            });
+    }
+
+    function para(txt, color) {
+        var c = color || 'black';
+        $d.append('p')
+            .text(txt)
+            .style({
+                padding: '2px 8px',
+                color: c
+            });
+    }
+
+    function load(view, ctx, flags) {
+        var c = ctx || '(undefined)',
+            f = flags ? d3.map(flags).keys() : [];
+
+        $d = view.$div;
+
+        para(intro);
+
+        suffixes.forEach(function (s) {
+            note(hashPrefix + s);
+        });
+
+        para('View ID: ' + view.vid, 'blue');
+        para('Context: ' + c, 'blue');
+        para('Flags: { ' + f.join(', ') + ' }', 'magenta');
+    }
+
+    // == register the view here, with links to lifecycle callbacks
+
+    onos.ui.addView('sampleHash', {
+        reset: true,    // empty the div on reset
+        load: load
+    });
+
+}(ONOS));
diff --git a/web/gui/src/main/webapp/topo2.css b/web/gui/src/main/webapp/topo2.css
index c4d9a2d..2602f6f 100644
--- a/web/gui/src/main/webapp/topo2.css
+++ b/web/gui/src/main/webapp/topo2.css
@@ -20,55 +20,59 @@
  @author Simon Hunt
  */
 
-svg #topo-bg {
+#topo svg #topo-bg {
     opacity: 0.5;
 }
 
 /* NODES */
 
-svg .node.device {
+#topo svg .node.device {
     stroke: none;
     stroke-width: 1.5px;
     cursor: pointer;
 }
 
-svg .node.device rect {
+#topo svg .node.device rect {
     stroke-width: 1.5px;
 }
 
-svg .node.device.fixed rect {
+#topo svg .node.device.fixed rect {
     stroke-width: 1.5;
     stroke: #ccc;
 }
 
-svg .node.device.switch {
+#topo svg .node.device.switch {
     fill: #17f;
 }
 
-svg .node.device.roadm {
+#topo svg .node.device.roadm {
     fill: #03c;
 }
 
-svg .node text {
+#topo svg .node.host {
+    fill: #846;
+}
+
+#topo svg .node text {
     stroke: none;
     fill: white;
     font: 10pt sans-serif;
     pointer-events: none;
 }
 
-svg .node.selected rect,
-svg .node.selected circle {
+#topo svg .node.selected rect,
+#topo svg .node.selected circle {
     filter: url(#blue-glow);
 }
 
 /* LINKS */
 
-svg .link {
+#topo svg .link {
     opacity: .7;
 }
 
 /* for debugging */
-svg .node circle.debug {
+#topo svg .node circle.debug {
     fill: white;
     stroke: red;
 }
diff --git a/web/gui/src/main/webapp/topo2.js b/web/gui/src/main/webapp/topo2.js
index acd2464..75fb99b 100644
--- a/web/gui/src/main/webapp/topo2.js
+++ b/web/gui/src/main/webapp/topo2.js
@@ -132,8 +132,21 @@
             links: [],
             lookup: {}
         },
+        scenario = {
+            evDir: 'json/ev/',
+            evScenario: '/scenario.json',
+            evPrefix: '/ev_',
+            evOnos: '_onos.json',
+            evUi: '_ui.json',
+            ctx: null,
+            params: {},
+            evNumber: 0,
+            view: null,
+            debug: false
+        },
         webSock,
-        labelIdx = 0,
+        deviceLabelIndex = 0,
+        hostLabelIndex = 0,
 
         selectOrder = [],
         selections = {},
@@ -155,10 +168,6 @@
     // ==============================
     // For Debugging / Development
 
-    var eventPrefix = 'json/eventTest_',
-        eventNumber = 0,
-        alertNumber = 0;
-
     function note(label, msg) {
         console.log('NOTE: ' + label + ': ' + msg);
     }
@@ -175,32 +184,71 @@
         view.alert('test');
     }
 
-    function injectTestEvent(view) {
+    function abortIfLive() {
         if (config.useLiveData) {
-            view.alert("Sorry, currently using live data..");
-            return;
+            scenario.view.alert("Sorry, currently using live data..");
+            return true;
         }
+        return false;
+    }
 
-        eventNumber++;
-        var eventUrl = eventPrefix + eventNumber + '.json';
+    function testDebug(msg) {
+        if (scenario.debug) {
+            scenario.view.alert(msg);
+        }
+    }
 
-        d3.json(eventUrl, function(err, data) {
+    function injectTestEvent(view) {
+        if (abortIfLive()) { return; }
+        var sc = scenario,
+            evn = ++sc.evNumber,
+            pfx = sc.evDir + sc.ctx + sc.evPrefix + evn,
+            onosUrl = pfx + sc.evOnos,
+            uiUrl = pfx + sc.evUi;
+
+        tryOnosEvent(onosUrl, uiUrl);
+    }
+
+    // TODO: tryOnosEvent/tryUiEvent folded into recursive function.
+    function tryOnosEvent(onosUrl, uiUrl) {
+        var v = scenario.view;
+        d3.json(onosUrl, function(err, data) {
             if (err) {
-                view.dataLoadError(err, eventUrl);
+                if (err.status === 404) {
+                    tryUiEvent(uiUrl);
+                } else {
+                    v.alert('non-404 error:\n\n' + onosUrl + '\n\n' + err);
+                }
             } else {
+                testDebug('loaded: ' + onosUrl);
                 handleServerEvent(data);
             }
         });
     }
 
-    function injectStartupEvents(view) {
-        if (config.useLiveData) {
-            view.alert("Sorry, currently using live data..");
-            return;
-        }
+    function tryUiEvent(uiUrl) {
+        var v = scenario.view;
+        d3.json(uiUrl, function(err, data) {
+            if (err) {
+                v.alert('Error:\n\n' + uiUrl + '\n\n' +
+                        err.status + ': ' + err.statusText);
+            } else {
+                testDebug('loaded: ' + uiUrl);
+                handleUiEvent(data);
+            }
+        });
+    }
 
-        var lastStartupEvent = 32;
-        while (eventNumber < lastStartupEvent) {
+    function handleUiEvent(data) {
+        testDebug('handleUiEvent(): ' + data.event);
+        // TODO:
+    }
+
+    function injectStartupEvents(view) {
+        var last = scenario.params.lastAuto || 0;
+        if (abortIfLive()) { return; }
+
+        while (scenario.evNumber < last) {
             injectTestEvent(view);
         }
     }
@@ -211,14 +259,16 @@
     }
 
     function cycleLabels() {
-        labelIdx = (labelIdx === network.deviceLabelCount - 1) ? 0 : labelIdx + 1;
+        deviceLabelIndex = (deviceLabelIndex === network.deviceLabelCount - 1) ? 0 : deviceLabelIndex + 1;
 
         function niceLabel(label) {
             return (label && label.trim()) ? label : '.';
         }
 
         network.nodes.forEach(function (d) {
-            var idx = (labelIdx < d.labels.length) ? labelIdx : 0,
+            if (d.class !== 'device') { return; }
+
+            var idx = (deviceLabelIndex < d.labels.length) ? deviceLabelIndex : 0,
                 node = d3.select('#' + safeId(d.id)),
                 box;
 
@@ -303,9 +353,14 @@
 
     var eventDispatch = {
         addDevice: addDevice,
-        updateDevice: updateDevice,
-        removeDevice: removeDevice,
+        updateDevice: stillToImplement,
+        removeDevice: stillToImplement,
         addLink: addLink,
+        updateLink: stillToImplement,
+        removeLink: stillToImplement,
+        addHost: addHost,
+        updateHost: stillToImplement,
+        removeHost: stillToImplement,
         showPath: showPath
     };
 
@@ -320,18 +375,6 @@
         network.force.start();
     }
 
-    function updateDevice(data) {
-        var device = data.payload;
-        note('updateDevice', device.id);
-
-    }
-
-    function removeDevice(data) {
-        var device = data.payload;
-        note('removeDevice', device.id);
-
-    }
-
     function addLink(data) {
         var link = data.payload,
             lnk = createLink(link);
@@ -345,11 +388,35 @@
         }
     }
 
+    function addHost(data) {
+        var host = data.payload,
+            node = createHostNode(host),
+            lnk;
+
+        note('addHost', node.id);
+        network.nodes.push(node);
+        network.lookup[host.id] = node;
+        updateNodes();
+
+        lnk = createHostLink(host);
+        if (lnk) {
+            network.links.push(lnk);
+            updateLinks();
+        }
+        network.force.start();
+    }
+
     function showPath(data) {
         network.view.alert(data.event + "\n" + data.payload.links.length);
     }
 
-    // ....
+    // ...............................
+
+    function stillToImplement(data) {
+        var p = data.payload;
+        note(data.event, p.id);
+        network.view.alert('Not yet implemented: "' + data.event + '"');
+    }
 
     function unknownEvent(data) {
         network.view.alert('Unknown event type: "' + data.event + '"');
@@ -367,6 +434,35 @@
         return 'translate(' + x + ',' + y + ')';
     }
 
+    function createHostLink(host) {
+        var src = host.id,
+            dst = host.cp.device,
+            srcNode = network.lookup[src],
+            dstNode = network.lookup[dst],
+            lnk;
+
+        if (!dstNode) {
+            // TODO: send warning message back to server on websocket
+            network.view.alert('switch not on map for link\n\n' +
+            'src = ' + src + '\ndst = ' + dst);
+            return null;
+        }
+
+        lnk = {
+            id: safeId(src) + '~' + safeId(dst),
+            source: srcNode,
+            target: dstNode,
+            class: 'link',
+            svgClass: 'link hostLink',
+            x1: srcNode.x,
+            y1: srcNode.y,
+            x2: dstNode.x,
+            y2: dstNode.y,
+            width: 1
+        };
+        return lnk;
+    }
+
     function createLink(link) {
         var type = link.type,
             src = link.src,
@@ -451,6 +547,22 @@
         return node;
     }
 
+    function createHostNode(host) {
+        // start with the object as is
+        var node = host;
+
+        // Augment as needed...
+        node.class = 'host';
+        node.svgClass = 'node host';
+        // TODO: consider placing near its switch, if [x,y] not defined
+        positionNode(node);
+
+        // cache label array length
+        network.hostLabelCount = host.labels.length;
+
+        return node;
+    }
+
     function positionNode(node) {
         var meta = node.metaUi,
             x = 0,
@@ -525,7 +637,7 @@
         entering.filter('.device').each(function (d) {
             var node = d3.select(this),
                 icon = iconUrl(d),
-                idx = (labelIdx < d.labels.length) ? labelIdx : 0,
+                idx = (deviceLabelIndex < d.labels.length) ? deviceLabelIndex : 0,
                 box;
 
             node.append('rect')
@@ -568,6 +680,32 @@
             }
         });
 
+        // augment host nodes...
+        entering.filter('.host').each(function (d) {
+            var node = d3.select(this),
+                idx = (hostLabelIndex < d.labels.length) ? hostLabelIndex : 0,
+                box;
+
+            node.append('circle')
+                .attr('r', 8);     // TODO: define host circle radius
+
+            // TODO: are we attaching labels to hosts?
+            node.append('text')
+                .text(d.labels[idx])
+                .attr('dy', '1.1em');
+
+            // debug function to show the modelled x,y coordinates of nodes...
+            if (debug('showNodeXY')) {
+                node.select('circle').attr('fill-opacity', 0.5);
+                node.append('circle')
+                    .attr({
+                        class: 'debug',
+                        cx: 0,
+                        cy: 0,
+                        r: '3px'
+                    });
+            }
+        });
 
         // operate on both existing and new nodes, if necessary
         //node .foo() .bar() ...
@@ -643,7 +781,7 @@
             if (webSock.ws) {
                 webSock.ws.send(message);
             } else {
-                network.view.alert('no web socket open');
+                network.view.alert('no web socket open\n\n' + message);
             }
         }
 
@@ -714,7 +852,7 @@
         //flyinPane(null);
     }
 
-
+    // TODO: this click handler does not get unloaded when the view does
     $('#view').on('click', function(e) {
         if (!$(e.target).closest('.node').length) {
             if (!e.metaKey) {
@@ -723,6 +861,33 @@
         }
     });
 
+
+    function prepareScenario(view, ctx, dbg) {
+        var sc = scenario,
+            urlSc = sc.evDir + ctx + sc.evScenario;
+
+        if (!ctx) {
+            view.alert("No scenario specified (null ctx)");
+            return;
+        }
+
+        sc.view = view;
+        sc.ctx = ctx;
+        sc.debug = dbg;
+        sc.evNumber = 0;
+
+        d3.json(urlSc, function(err, data) {
+            var p = data && data.params || {};
+            if (err) {
+                view.alert('No scenario found:\n\n' + urlSc + '\n\n' + err);
+            } else {
+                sc.params = p;
+                view.alert("Scenario loaded: " + ctx + '\n\n' + data.title);
+            }
+        });
+
+    }
+
     // ==============================
     // View life-cycle callbacks
 
@@ -781,14 +946,11 @@
         }
 
         function atDragEnd(d, self) {
-            // once we've finished moving, pin the node in position,
-            // if it is a device (not a host)
-            if (d.class === 'device') {
-                d.fixed = true;
-                d3.select(self).classed('fixed', true);
-                if (config.useLiveData) {
-                    tellServerCoords(d);
-                }
+            // once we've finished moving, pin the node in position
+            d.fixed = true;
+            d3.select(self).classed('fixed', true);
+            if (config.useLiveData) {
+                tellServerCoords(d);
             }
         }
 
@@ -814,9 +976,14 @@
         network.drag = d3u.createDragBehavior(network.force, selectCb, atDragEnd);
     }
 
-    function load(view, ctx) {
+    function load(view, ctx, flags) {
         // cache the view token, so network topo functions can access it
         network.view = view;
+        config.useLiveData = !flags.local;
+
+        if (!config.useLiveData) {
+            prepareScenario(view, ctx, flags.debug);
+        }
 
         // set our radio buttons and key bindings
         view.setRadio(btnSet);