diff --git a/src/packet.js b/src/packet.js
index 98a5b031..fb795d71 100644
--- a/src/packet.js
+++ b/src/packet.js
@@ -18,14 +18,36 @@ var optionKeys = [
 
 
 
-var Packet = Header.extend({
+var Packet = Header.extend(/** @lends Packet# */ {
 
+    /**
+     * The command field of this VBus packet. See the VBus Protocol specification for details.
+     * @type {number}
+     */
     command: 0,
 
+    /**
+     * The number of frames of this VBus packet. Each frame can hold four bytes of payload.
+     * @type {number}
+     */
     frameCount: 0,
 
+    /**
+     * The buffer containing the frame data of this VBus packet.
+     */
     frameData: null,
 
+    /**
+     * Creates a new Packet instance and optionally initializes its members with the given values.
+     *
+     * @constructs
+     * @augments Header
+     * @param {object} options Initialization values for this instance's members
+     * @param {number} options.command {@link Packet#command}
+     * @param {number} options.frameCount {@link Packet#frameCount}
+     * @param {Buffer} options.frameData {@link Packet#frameData}
+     * @see Header#constructor
+     */
     constructor: function(options) {
         Header.call(this, options);
 
@@ -50,11 +72,9 @@ var Packet = Header.extend({
         var buffer;
         if (origBuffer === undefined) {
             buffer = new Buffer(length);
+        } else if (start + length <= end) {
+            buffer = origBuffer.slice(start, start + length);
         } else {
-            buffer = origBuffer.slice(start, end);
-        }
-
-        if (buffer.length < length) {
             throw new Error('Buffer too small');
         }
 
@@ -93,7 +113,7 @@ var Packet = Header.extend({
         return result;
     },
 
-}, {
+}, /** @lends Packet */ {
 
     fromLiveBuffer: function(buffer, start, end) {
         var frameCount = buffer [start + 8];
diff --git a/test/specs/packet.spec.js b/test/specs/packet.spec.js
index 9076460c..1e36e561 100644
--- a/test/specs/packet.spec.js
+++ b/test/specs/packet.spec.js
@@ -15,160 +15,235 @@ var connectionSpec = require('./connection.spec');
 
 describe('Packet', function() {
 
-    it('should be a constructor function', function() {
-        expect(Packet).to.be.a('function');
-        expect(Packet.extend).to.be.a('function');
-    });
+    describe('#constructor', function() {
 
-    it('should have reasonable defaults', function() {
-        var before = new Date();
-        var packet = new Packet();
-        var after = new Date();
-
-        expect(packet).to.be.an('object');
-        expect(packet.timestamp).to.be.an.instanceOf(Date);
-        expect(packet.timestamp.getTime()).to.be.within(before.getTime(), after.getTime());
-        expect(packet.channel).to.equal(0);
-        expect(packet.destinationAddress).to.equal(0);
-        expect(packet.sourceAddress).to.equal(0);
-        expect(packet.command).to.equal(0);
-        expect(packet.frameCount).to.equal(0);
-        expect(packet.frameData).to.be.an.instanceOf(Buffer);
-        expect(packet.frameData.length).to.equal(127 * 4);
-    });
+        it('should be a constructor function', function() {
+            expect(Packet).to.be.a('function');
+            expect(Packet.extend).to.be.a('function');
+        });
 
-    it('should copy certain options', function() {
-        var frameData = new Buffer(13 * 4);
-        for (var i = 0; i < frameData.length; i++) {
-            frameData [i] = i * 4;
-        }
-
-        var options = {
-            timestamp: new Date(0),
-            channel: 0x1337,
-            destinationAddress: 0x2336,
-            sourceAddress: 0x3335,
-            command: 0x4334,
-            frameCount: 13,
-            frameData: frameData,
-            junk: 0x7331
-        };
-
-        var packet = new Packet(options);
-
-        expect(packet).to.be.an('object');
-
-        _.forEach(options, function(refValue, key) {
-            var value = packet [key];
-
-            if ((value instanceof Buffer) && (refValue instanceof Buffer)) {
-                value = value.slice(0, refValue.length).toString('hex');
-                refValue = refValue.toString('hex');
-            }
-            if (key === 'junk') {
-                refValue = undefined;
+        it('should have reasonable defaults', function() {
+            var before = new Date();
+            var packet = new Packet();
+            var after = new Date();
+
+            expect(packet).to.be.an('object');
+            expect(packet.timestamp).to.be.an.instanceOf(Date);
+            expect(packet.timestamp.getTime()).to.be.within(before.getTime(), after.getTime());
+            expect(packet.channel).to.equal(0);
+            expect(packet.destinationAddress).to.equal(0);
+            expect(packet.sourceAddress).to.equal(0);
+            expect(packet.command).to.equal(0);
+            expect(packet.frameCount).to.equal(0);
+            expect(packet.frameData).to.be.an.instanceOf(Buffer);
+            expect(packet.frameData.length).to.equal(127 * 4);
+        });
+
+        it('should copy certain options', function() {
+            var frameData = new Buffer(13 * 4);
+            for (var i = 0; i < frameData.length; i++) {
+                frameData [i] = i * 4;
             }
 
-            expect(value).to.equal(refValue, key);
+            var options = {
+                timestamp: new Date(0),
+                channel: 0x1337,
+                destinationAddress: 0x2336,
+                sourceAddress: 0x3335,
+                command: 0x4334,
+                frameCount: 13,
+                frameData: frameData,
+                junk: 0x7331
+            };
+
+            var packet = new Packet(options);
+
+            expect(packet).to.be.an('object');
+
+            _.forEach(options, function(refValue, key) {
+                var value = packet [key];
+
+                if ((value instanceof Buffer) && (refValue instanceof Buffer)) {
+                    value = value.slice(0, refValue.length).toString('hex');
+                    refValue = refValue.toString('hex');
+                }
+                if (key === 'junk') {
+                    refValue = undefined;
+                }
+
+                expect(value).to.equal(refValue, key);
+            });
         });
     });
 
-    it('should have a toLiveBuffer method', function() {
-        var frameData = new Buffer(13 * 4);
-        for (var i = 0; i < frameData.length; i++) {
-            frameData [i] = i * 4;
-        }
-
-        var options = {
-            destinationAddress: 0x2336,
-            sourceAddress: 0x3335,
-            command: 0x4334,
-            frameCount: 13,
-            frameData: frameData,
-        };
-
-        var packet = new Packet(options);
-
-        var buffer = packet.toLiveBuffer();
-
-        expect(buffer).to.be.an.instanceOf(Buffer);
-        expect(buffer.length).to.equal(88);
-        expect(buffer.toString('hex')).to.equal('aa362335331034430d2a0004080c00671014181c00272024282c00673034383c00274044484c00675054585c00276064686c00677074787c00270004080c0f581014181c0f182024282c0f583034383c0f184044484c0f58');
-
-/*
-        var stats = connectionSpec.parseRawDataOnce(buffer);
-        expect(stats.rawDataCount).to.equal(buffer.length);
-        expect(stats.junkDataCount).to.equal(0);
-        expect(stats.packetCount).to.equal(1);
-        expect(stats.lastPacket).to.be.an.instanceOf(Packet);
-
-        _.forEach(options, function(optionsValue, key) {
-            var value = stats.lastPacket [key];
-            var refValue = packet [key];
-
-            if (value instanceof Buffer) {
-                value = value.toString('hex');
+    describe('#toLiveBuffer', function() {
+
+        it('should be a method', function() {
+            expect(Packet.prototype.toLiveBuffer).to.be.a('function');
+        });
+
+        it('should work correctly without a buffer', function() {
+            var frameData = new Buffer(13 * 4);
+            for (var i = 0; i < frameData.length; i++) {
+                frameData [i] = i * 4;
             }
-            if (refValue instanceof Buffer) {
-                refValue = refValue.toString('hex');
+
+            var options = {
+                destinationAddress: 0x2336,
+                sourceAddress: 0x3335,
+                command: 0x4334,
+                frameCount: 13,
+                frameData: frameData,
+            };
+
+            var packet = new Packet(options);
+
+            var buffer = packet.toLiveBuffer();
+
+            expect(buffer).to.be.an.instanceOf(Buffer);
+            expect(buffer.length).to.equal(88);
+            expect(buffer.toString('hex')).to.equal('aa362335331034430d2a0004080c00671014181c00272024282c00673034383c00274044484c00675054585c00276064686c00677074787c00270004080c0f581014181c0f182024282c0f583034383c0f184044484c0f58');
+
+    /*
+            var stats = connectionSpec.parseRawDataOnce(buffer);
+            expect(stats.rawDataCount).to.equal(buffer.length);
+            expect(stats.junkDataCount).to.equal(0);
+            expect(stats.packetCount).to.equal(1);
+            expect(stats.lastPacket).to.be.an.instanceOf(Packet);
+
+            _.forEach(options, function(optionsValue, key) {
+                var value = stats.lastPacket [key];
+                var refValue = packet [key];
+
+                if (value instanceof Buffer) {
+                    value = value.toString('hex');
+                }
+                if (refValue instanceof Buffer) {
+                    refValue = refValue.toString('hex');
+                }
+
+                expect(value).to.equal(refValue, key);
+            });
+    */
+        });
+
+        it('should work correctly with a buffer', function() {
+            var frameData = new Buffer(13 * 4);
+            for (var i = 0; i < frameData.length; i++) {
+                frameData [i] = i * 4;
             }
 
-            expect(value).to.equal(refValue, key);
+            var options = {
+                destinationAddress: 0x2336,
+                sourceAddress: 0x3335,
+                command: 0x4334,
+                frameCount: 13,
+                frameData: frameData,
+            };
+
+            var packet = new Packet(options);
+
+            var bigBuffer = new Buffer(800);
+
+            var buffer = packet.toLiveBuffer(bigBuffer, 100, 200);
+
+            expect(buffer).to.be.an.instanceOf(Buffer);
+            expect(buffer.length).to.equal(88);
+            expect(buffer.toString('hex')).to.equal('aa362335331034430d2a0004080c00671014181c00272024282c00673034383c00274044484c00675054585c00276064686c00677074787c00270004080c0f581014181c0f182024282c0f583034383c0f184044484c0f58');
         });
-*/
-    });
 
-    it('should have a fromLiveBuffer function', function() {
-        var frameData = new Buffer(13 * 4);
-        for (var i = 0; i < frameData.length; i++) {
-            frameData [i] = i * 4;
-        }
+        it('should throw if buffer is too small', function() {
+            var frameData = new Buffer(13 * 4);
+            for (var i = 0; i < frameData.length; i++) {
+                frameData [i] = i * 4;
+            }
 
-        var options = {
-            destinationAddress: 0x2336,
-            sourceAddress: 0x3335,
-            command: 0x4334,
-            frameCount: 13,
-            frameData: frameData,
-        };
+            var options = {
+                destinationAddress: 0x2336,
+                sourceAddress: 0x3335,
+                command: 0x4334,
+                frameCount: 13,
+                frameData: frameData,
+            };
 
-        var buffer = new Buffer('aa362335331034430d2a0004080c00671014181c00272024282c00673034383c00274044484c00675054585c00276064686c00677074787c00270004080c0f581014181c0f182024282c0f583034383c0f184044484c0f58', 'hex');
+            var packet = new Packet(options);
 
-        var packet = Packet.fromLiveBuffer(buffer, 0, buffer.length);
+            var bigBuffer = new Buffer(800);
 
-        expect(packet).to.be.an.instanceOf(Packet);
+            expect(function() {
+                packet.toLiveBuffer(bigBuffer, 100, 180);
+            }).to.throw();
+        });
 
-        _.forEach(options, function(refValue, key) {
-            var value = packet [key];
+    });
 
-            if ((value instanceof Buffer) && (refValue instanceof Buffer)) {
-                value = value.slice(0, refValue.length).toString('hex');
-                refValue = refValue.toString('hex');
+    describe('.fromLiveBuffer', function() {
+
+        it('should be a function', function() {
+            expect(Packet.fromLiveBuffer).to.be.a('function');
+        });
+
+        it('should work correctly', function() {
+            var frameData = new Buffer(13 * 4);
+            for (var i = 0; i < frameData.length; i++) {
+                frameData [i] = i * 4;
             }
 
-            expect(value).to.equal(refValue, key);
+            var options = {
+                destinationAddress: 0x2336,
+                sourceAddress: 0x3335,
+                command: 0x4334,
+                frameCount: 13,
+                frameData: frameData,
+            };
+
+            var buffer = new Buffer('aa362335331034430d2a0004080c00671014181c00272024282c00673034383c00274044484c00675054585c00276064686c00677074787c00270004080c0f581014181c0f182024282c0f583034383c0f184044484c0f58', 'hex');
+
+            var packet = Packet.fromLiveBuffer(buffer, 0, buffer.length);
+
+            expect(packet).to.be.an.instanceOf(Packet);
+
+            _.forEach(options, function(refValue, key) {
+                var value = packet [key];
+
+                if ((value instanceof Buffer) && (refValue instanceof Buffer)) {
+                    value = value.slice(0, refValue.length).toString('hex');
+                    refValue = refValue.toString('hex');
+                }
+
+                expect(value).to.equal(refValue, key);
+            });
         });
+
     });
 
-    it('should have a working getId method', function() {
-        var frameData = new Buffer(13 * 4);
-        for (var i = 0; i < frameData.length; i++) {
-            frameData [i] = i * 4;
-        }
-
-        var options = {
-            channel: 0x13,
-            destinationAddress: 0x2336,
-            sourceAddress: 0x3335,
-            command: 0x4334,
-            frameCount: 13,
-            frameData: frameData,
-        };
-
-        var packet = new Packet(options);
-
-        expect(packet).to.be.an('object');
-        expect(packet.getId()).to.equal('13_2336_3335_10_4334');
+    describe('#getId', function() {
+
+        it('should be a method', function() {
+            expect(Packet.prototype.getId).to.be.a('function');
+        });
+
+        it('should work correctly', function() {
+            var frameData = new Buffer(13 * 4);
+            for (var i = 0; i < frameData.length; i++) {
+                frameData [i] = i * 4;
+            }
+
+            var options = {
+                channel: 0x13,
+                destinationAddress: 0x2336,
+                sourceAddress: 0x3335,
+                command: 0x4334,
+                frameCount: 13,
+                frameData: frameData,
+            };
+
+            var packet = new Packet(options);
+
+            expect(packet).to.be.an('object');
+            expect(packet.getId()).to.equal('13_2336_3335_10_4334');
+        });
+
     });
 
 });